Showing papers in "Crustaceana in 2009"

Flexible omnivory in dikerogammarus villosus (Sowinsky, 1894) (Amphipoda) - amphipod pilot species project (ampis) report 5

Abstract: [Feeding in Dikerogammarus villosus (Sowinsky, 1894) males was observed in the field and recorded on video in the laboratory. The following feeding modes were recognized: detritus feeding, grazing, particle feeding, coprophagy, predation on benthic and free swimming invertebrates, predation on fish eggs and larvae, as well as feeding on byssus threads of the zebra mussel, Dreissena polymorpha (Pallas, 1771). The feeding methods are described and illustrated with screenshots of video recordings. The very flexible feeding modes of D. villosus, which make diet switches possible, form a trait that must be an important factor in the invasion success of this Ponto-Caspian gammaridean species, and may thus explain for a great deal its high ecosystem impact. L'alimentation des mâles de Dikerogammarus villosus (Sowinsky, 1894) a ete observee dans la nature et enregistree par video au laboratoire. Les differents modes d'alimentation suivants ont ete reconnus: detritivore, broutage, particulaire, coprophage, predation sur des invertebres benthiques et nageurs, predation d'aeufs et de larves de poissons, et aussi alimentation sur les amas de la moule rayee Dreissena polymorpha (Pallas, 1771).Les methodes d'alimentation sont decrites et illustrees avec des photos provenant d'enregistrements videos. Le mode d'alimentation tres flexible de D. villosus, qui permet des changements de regime, est un trait qui est peut-etre un facteur important dans le succes d'invasion de cette espece de gammaride Ponto-Caspien et qui peut expliquer en grande partie son fort impact sur l'ecosysteme., Feeding in Dikerogammarus villosus (Sowinsky, 1894) males was observed in the field and recorded on video in the laboratory. The following feeding modes were recognized: detritus feeding, grazing, particle feeding, coprophagy, predation on benthic and free swimming invertebrates, predation on fish eggs and larvae, as well as feeding on byssus threads of the zebra mussel, Dreissena polymorpha (Pallas, 1771). The feeding methods are described and illustrated with screenshots of video recordings. The very flexible feeding modes of D. villosus, which make diet switches possible, form a trait that must be an important factor in the invasion success of this Ponto-Caspian gammaridean species, and may thus explain for a great deal its high ecosystem impact. L'alimentation des mâles de Dikerogammarus villosus (Sowinsky, 1894) a ete observee dans la nature et enregistree par video au laboratoire. Les differents modes d'alimentation suivants ont ete reconnus: detritivore, broutage, particulaire, coprophage, predation sur des invertebres benthiques et nageurs, predation d'aeufs et de larves de poissons, et aussi alimentation sur les amas de la moule rayee Dreissena polymorpha (Pallas, 1771).Les methodes d'alimentation sont decrites et illustrees avec des photos provenant d'enregistrements videos. Le mode d'alimentation tres flexible de D. villosus, qui permet des changements de regime, est un trait qui est peut-etre un facteur important dans le succes d'invasion de cette espece de gammaride Ponto-Caspien et qui peut expliquer en grande partie son fort impact sur l'ecosysteme.]

Effects of serotonin, dopamine, octopamine, and spiperone on ovarian maturation and embryonic development in the giant freshwater prawn, Macrobrachium rosenbergii (De Man, 1879)

Abstract: [Mature female Macrobrachium rosenbergii in stage I of their ovarian cycle were divided into 17 groups (14 experimental groups and 3 controls) of 28 animals each. Animals in each experimental group were injected intramuscularly with 2-3 doses of serotonin (5-HT), dopamine (DA), octopamine (OA), spiperone (SP), or 5-HT plus SP, at four-day intervals from day 1 to 49. Five animals each in every group were sacrificed, respectively, at day 14, 25, and 49 to evaluate the gonadosomatic index (GSI) and oocyte diameters. The experimental groups that received the doses of 2.5 × 10−5, 2.5 × 10−6 mol of 5-HT/prawn, 2.5 × 10−5, 2.5 × 10−6, 2.5 × 10−7 mol of 5-HT/prawn plus 2.7 × 10−7 mol of SP/prawn, as well as SP alone at the dose of 5.4 × 10−7 mol of SP/prawn, exhibited significantly shorter periods of ovarian maturation and embryonic development, as well as increased GSI values and oocyte diameters, when compared with vehicle-injected and untreated control groups. In contrast, groups injected with DA and OA at similar doses showed decreased ovarian maturation, oocyte diameters, and embryonic periods, but no differences in GSI, when compared with control groups. For the number of eggs per spawn, the groups of animals that received 5-HT at doses of 2.5 × 10−5 and 2.5 × 10−6 mol/prawn, 5-HT at doses of 2.5 × 10−5 mol plus SP at 2.7 × 10−7 mol/prawn, 5-HT at 2.5 × 10−6 mol plus SP at 2.7 × 10−7 mol/prawn, and SP at a dose of 2.7 × 10−7 mol/prawn, yielded higher numbers than the control groups, and with a significant difference (P < 0.05). All DA and OA injected groups showed lower numbers of eggs when compared to the control groups. Eggs from all these experimental groups exhibited equally good quality both among each other and in comparison with control groups, as judged from the percentage of fertilized eggs. Des femelles matures de Macrobrachium rosenbergii en stade I de leur cycle ovarien ont ete divisees en 17 groupes (14 groupes experimentaux et 3 groupes controles) de 28 animaux chacun. Les animaux dans chaque groupe experimental ont ete injectes avec 2-3 doses de serotonine (5-HT), dopamine (DA), octopamine (OA), spiperone (SP), ou 5-HT plus SP, tous les quatre jours du 1er au 49eme jour. Cinq animaux dans chaque groupe ont ete sacrifies respectivement aux jours 14, 25, et 49 afin d'evaluer l'index gonadosomatique (GSI) et le diametre des oocytes. Les groupes experimentaux ayant recu des doses de 2,5 × 10−5, 2,5 × 10−6 mol de 5-HT/crevette, 2,5 × 10−5, 2,5 × 10−6, 2,5 × 10−7 mol de 5-HT/crevette plus 2,7 × 10−7 mol de SP/crevette, ainsi que SP, seule la dose de 5,4 × 10−7 mol de SP/crevette, montrent une periode de maturation ovarienne et de developpement embryonnaire significativement plus courte, ainsi que une valeur de GSI et un diametre des oocytes plus eleve par comparaison avec les groupes injectes seulement avec le solvant et les groupes controles pas injectes. Par contre les groupes injectes avec DA et OA a des doses similaires montrent une diminution de la maturation ovarienne, du diametre des ovocytes et de la periode embryonnaire, mais aucune difference avec la GSI comparee aux autres groupes. Pour le nombre d'œufs par ponte, les groupes d'animaux qui ont recu de la 5-HT aux doses de 2,5 × 10−5 et 2,5 × 10−6 mol/crevette, 5-HT aux doses de 2,5 × 10−5 mol plus SP a 2,7 × 10−7 mol/crevette, 5-HT a 2,5 × 10−6 mol plus SP a 2,7 × 10−7 mol/crevette, et SP a une dose de 2,7 × 10−7 mol/crevette, portent un nombre plus eleve que les groupes controles avec une difference significative (P < 0,05). Tous les groupes injectes avec DA et OA montrent par comparaison aux groupes controles, un nombre d'œufs plus faible. En se basant sur le pourcentage du nombre d'œufs fecondes, les oeufs de tous les groupes experimentaux presentent la meme bonne qualite les uns par rapport aux autres et par comparaison avec les groupes controles., Mature female Macrobrachium rosenbergii in stage I of their ovarian cycle were divided into 17 groups (14 experimental groups and 3 controls) of 28 animals each. Animals in each experimental group were injected intramuscularly with 2-3 doses of serotonin (5-HT), dopamine (DA), octopamine (OA), spiperone (SP), or 5-HT plus SP, at four-day intervals from day 1 to 49. Five animals each in every group were sacrificed, respectively, at day 14, 25, and 49 to evaluate the gonadosomatic index (GSI) and oocyte diameters. The experimental groups that received the doses of 2.5 × 10−5, 2.5 × 10−6 mol of 5-HT/prawn, 2.5 × 10−5, 2.5 × 10−6, 2.5 × 10−7 mol of 5-HT/prawn plus 2.7 × 10−7 mol of SP/prawn, as well as SP alone at the dose of 5.4 × 10−7 mol of SP/prawn, exhibited significantly shorter periods of ovarian maturation and embryonic development, as well as increased GSI values and oocyte diameters, when compared with vehicle-injected and untreated control groups. In contrast, groups injected with DA and OA at similar doses showed decreased ovarian maturation, oocyte diameters, and embryonic periods, but no differences in GSI, when compared with control groups. For the number of eggs per spawn, the groups of animals that received 5-HT at doses of 2.5 × 10−5 and 2.5 × 10−6 mol/prawn, 5-HT at doses of 2.5 × 10−5 mol plus SP at 2.7 × 10−7 mol/prawn, 5-HT at 2.5 × 10−6 mol plus SP at 2.7 × 10−7 mol/prawn, and SP at a dose of 2.7 × 10−7 mol/prawn, yielded higher numbers than the control groups, and with a significant difference (P < 0.05). All DA and OA injected groups showed lower numbers of eggs when compared to the control groups. Eggs from all these experimental groups exhibited equally good quality both among each other and in comparison with control groups, as judged from the percentage of fertilized eggs. Des femelles matures de Macrobrachium rosenbergii en stade I de leur cycle ovarien ont ete divisees en 17 groupes (14 groupes experimentaux et 3 groupes controles) de 28 animaux chacun. Les animaux dans chaque groupe experimental ont ete injectes avec 2-3 doses de serotonine (5-HT), dopamine (DA), octopamine (OA), spiperone (SP), ou 5-HT plus SP, tous les quatre jours du 1er au 49eme jour. Cinq animaux dans chaque groupe ont ete sacrifies respectivement aux jours 14, 25, et 49 afin d'evaluer l'index gonadosomatique (GSI) et le diametre des oocytes. Les groupes experimentaux ayant recu des doses de 2,5 × 10−5, 2,5 × 10−6 mol de 5-HT/crevette, 2,5 × 10−5, 2,5 × 10−6, 2,5 × 10−7 mol de 5-HT/crevette plus 2,7 × 10−7 mol de SP/crevette, ainsi que SP, seule la dose de 5,4 × 10−7 mol de SP/crevette, montrent une periode de maturation ovarienne et de developpement embryonnaire significativement plus courte, ainsi que une valeur de GSI et un diametre des oocytes plus eleve par comparaison avec les groupes injectes seulement avec le solvant et les groupes controles pas injectes. Par contre les groupes injectes avec DA et OA a des doses similaires montrent une diminution de la maturation ovarienne, du diametre des ovocytes et de la periode embryonnaire, mais aucune difference avec la GSI comparee aux autres groupes. Pour le nombre d'œufs par ponte, les groupes d'animaux qui ont recu de la 5-HT aux doses de 2,5 × 10−5 et 2,5 × 10−6 mol/crevette, 5-HT aux doses de 2,5 × 10−5 mol plus SP a 2,7 × 10−7 mol/crevette, 5-HT a 2,5 × 10−6 mol plus SP a 2,7 × 10−7 mol/crevette, et SP a une dose de 2,7 × 10−7 mol/crevette, portent un nombre plus eleve que les groupes controles avec une difference significative (P < 0,05). Tous les groupes injectes avec DA et OA montrent par comparaison aux groupes controles, un nombre d'œufs plus faible. En se basant sur le pourcentage du nombre d'œufs fecondes, les oeufs de tous les groupes experimentaux presentent la meme bonne qualite les uns par rapport aux autres et par comparaison avec les groupes controles.]

New species and new records of hydrothermal vent shrimps from New Zealand (Caridea: Alvinocarididae, Hippolytidae)

Abstract: Alvinocaris alexander sp. nov. (Alvinocarididae) and Lebbeus wera sp. nov. (Hippolytidae) are described from hydrothermal vents on the southern Kermadec Ridge, northern New Zealand. Alvinocaris alexander most closely resembles A. williamsi Shank & Martin, 2003 from the Mid-Atlantic Ridge, differing in rostral, antennular, and abdominal features. Alvinocaris alexander is apparently sympatric with A. niwa Webber, 2004, and comprises part of the type series of the latter. Lebbeus wera is the first species of the genus to be recorded from New Zealand waters and is most similar to other deep-water Lebbeus species including Lebbeus washingtonianus (Rathbun, 1902) and L. polyacanthus Komai, Hayashi & Kohtsuka, 2004, but is distinctive in its five dorsal postrostral teeth. The first records of the alvinocaridid, Nautilocaris saintlaurentae Komai & Segonzac, 2004, from Brothers Seamount, New Zealand, are reported, being previously known only from the North Fiji and Lau basins. Three genera and five species of caridean shrimp are now known from New Zealand hydrothermal vents. Alvinocaris alexander sp. nov. (Alvinocarididae) und Lebbeus wera sp. nov. (Hippolytidae) werden im Folgenden von hydrothermalen Quellen des sudlichen Kermadec Ruckens, Nord-Neuseeland, beschrieben. Alvinocaris alexander ahnelt A. williamsi Shank & Martin, 2003 vom Mittelatlantischen Rucken, unterscheidet sich aber in Merkmalen des Rostrums, der Antennen und des Abdomens. Alvinocaris alexander ist scheinbar sympatrisch mit A. niwa Webber, 2004, und stellt einen Teil dessen Typenserie dar. Lebbeus wera ist die erste Art dieser Gattung aus neuseelandischen Gewassern und ahnelt anderen Tiefseearten der Gattung Lebbeus wie Lebbeus washingtonianus (Rathbun, 1902) und L. polyacanthus Komai, Hayashi & Kohtsuka, 2004, unterscheidet sich von diesen allerdings durch seine funf dorsalen postrostralen Zahne. Erstmals wird hier die alvinocaridide Nautilocaris saintlaurentae Komai & Segonzac, 2004, von dem Brothers Seamount, Neuseeland, gemeldet. Bisher war diese Art nur vom Nord-Fidschi-Becken und dem Lau Becken bekannt. Damit sind drei Gattungen und funf Arten carideaner Garnele von neuseelandischen Hydrothermalquellen bekannt.

Cryptic species from cryptic space: the case of Niphargus fongi sp. n. (Amphipoda, Niphargidae)

Abstract: [Niphargus fongi sp. n. (Amphipoda, Niphargidae) is described from a cave in the Dinaric karst of southeastern Slovenia and its morphology is reported in detail. Its occurrence in pools of percolating water, some of which temporarily dry up, and its narrow distribution range suggest that the species lives in limestone fissures, possibly in the epikarst ecotone. Small though distinct diagnostic morphological characters support the species hypothesis based on molecular evidence. Re-evaluation of the degree of morphological differentiation in the light of molecular findings implies that the term "cryptic species", at least in some less well-studied taxa, may also depend on taxonomic evaluation of morphologically distinct populations. Additionally, a species described from a poorly sampled habitat constitutes a sample case of where taxonomic as well as ecological influences on biodiversity become apparent. Both incomplete taxonomy as well as insufficient sampling affect estimates of biodiversity in subterranean habitats. Niphargus fongi sp. n. (Amphipoda, Niphargidae) est decrit d'une grotte du karst dinarique de Slovenie sud-orientale et sa morphologie est decrite en detail. Sa presence dans les bassins d'eaux de percolation, dont certains s'assechent temporairement, et son aire de repartition etroite suggerent que l'espece vit dans les fissures du calcaire, et peut-etre dans l'ecotone epikarst. De petits, bien que distincts, caracteres morphologiques diagnostiques supportent l'hypothese d'espece a partir de l'evidence moleculaire. La reevaluation du degre de differenciation morphologique a la lumiere des resultats moleculaires impliquent que le terme "espece cryptique", au moins chez quelques taxons moins bien etudies, peut aussi dependre de l'evaluation taxonomique de populations morphologiquement distinctes. De plus, une espece decrite d'un habitat peu echantillonne constitue un cas dans lequel les influences taxonomiques comme ecologiques sur la biodiversite deviennent apparentes. Une taxonomie incomplete et un echantillonnage insuffisant affectent tous deux les estimations de la biodiversite dans les habitats souterrains., Niphargus fongi sp. n. (Amphipoda, Niphargidae) is described from a cave in the Dinaric karst of southeastern Slovenia and its morphology is reported in detail. Its occurrence in pools of percolating water, some of which temporarily dry up, and its narrow distribution range suggest that the species lives in limestone fissures, possibly in the epikarst ecotone. Small though distinct diagnostic morphological characters support the species hypothesis based on molecular evidence. Re-evaluation of the degree of morphological differentiation in the light of molecular findings implies that the term "cryptic species", at least in some less well-studied taxa, may also depend on taxonomic evaluation of morphologically distinct populations. Additionally, a species described from a poorly sampled habitat constitutes a sample case of where taxonomic as well as ecological influences on biodiversity become apparent. Both incomplete taxonomy as well as insufficient sampling affect estimates of biodiversity in subterranean habitats. Niphargus fongi sp. n. (Amphipoda, Niphargidae) est decrit d'une grotte du karst dinarique de Slovenie sud-orientale et sa morphologie est decrite en detail. Sa presence dans les bassins d'eaux de percolation, dont certains s'assechent temporairement, et son aire de repartition etroite suggerent que l'espece vit dans les fissures du calcaire, et peut-etre dans l'ecotone epikarst. De petits, bien que distincts, caracteres morphologiques diagnostiques supportent l'hypothese d'espece a partir de l'evidence moleculaire. La reevaluation du degre de differenciation morphologique a la lumiere des resultats moleculaires impliquent que le terme "espece cryptique", au moins chez quelques taxons moins bien etudies, peut aussi dependre de l'evaluation taxonomique de populations morphologiquement distinctes. De plus, une espece decrite d'un habitat peu echantillonne constitue un cas dans lequel les influences taxonomiques comme ecologiques sur la biodiversite deviennent apparentes. Une taxonomie incomplete et un echantillonnage insuffisant affectent tous deux les estimations de la biodiversite dans les habitats souterrains.]

Potential production of the caribbean spiny lobster (decapoda, palinura) fisheries

Abstract: [The spiny lobster Panulirus argus (Latreille, 1804) constitutes the most important fishery of the Caribbean: it accounts for nearly 42 000 tonnes. Evidence suggests that high fishing mortality (F) may have been overexploiting most stocks. An assessment was carried out providing the basis for a sustainable exploitation of the nine most important producing countries. Values were assessed and each fishery was simulated; age structure was reconstructed linking biological, economic, and social variables. The results show that advice is required to enhance recruitment and to restore biomass of most stocks. Among the nine fisheries examined in detail, the Bahamas, the main producer, is slightly overexploited, and the overexploitation of four others ranges from moderate to severe. An arbitrary F value, lower than the one producing the Maximum Sustainable Yield, or extreme reference point, is adopted as management target and was proposed for adoption by these fisheries; in order to attain the target, gradual F reductions are required to restore stock biomass in eight fisheries, and a slight increase of F in one case. La langosta Panulirus argus (Latreille, 1804) constituye la pesqueria mas importante del Caribe: se capturan cerca de 42,000 toneladas. La evidencia sugiere que la alta mortalidad por pesca (F) podria haber provocado la sobre explotacion de la mayoria de las poblaciones. Las pesquerias mas importantes fueron evaluadas, proporcionando las bases para una explotacion sustentable en nueve paises que la explotan. Se evaluaron los parametros de las poblaciones y cada pesqueria fue simulada; la estructura por edades fue reconstruida vinculando las variables biologicas, economicas y sociales. Los resultados sugieren que se requiere de un manejo informado para mejorar los niveles de reclutamiento y recuperar la mayoria de las poblaciones. De las nueve pesquerias analizadas en detalle, se encontro que la de las Bahamas el principal productor, esta ligeramente sobreexplotada y otras cuatro se encuentran en un grado de sobreexplotacion que va de moderado a severo. Se identifico un valor arbitrario de F, mas bajo que el requerido para el nivel de Rendimiento Maximo Sostenible que es un punto de referencia extremo y se propone aqui como objetivo de manejo para estas pesquerias; para el logro de ese objetivo, es necesario reducir gradualmente la F en ocho pesquerias para que sus biomasas se restablezcan y en un caso implica un ligero aumento de la F., The spiny lobster Panulirus argus (Latreille, 1804) constitutes the most important fishery of the Caribbean: it accounts for nearly 42 000 tonnes. Evidence suggests that high fishing mortality (F) may have been overexploiting most stocks. An assessment was carried out providing the basis for a sustainable exploitation of the nine most important producing countries. Values were assessed and each fishery was simulated; age structure was reconstructed linking biological, economic, and social variables. The results show that advice is required to enhance recruitment and to restore biomass of most stocks. Among the nine fisheries examined in detail, the Bahamas, the main producer, is slightly overexploited, and the overexploitation of four others ranges from moderate to severe. An arbitrary F value, lower than the one producing the Maximum Sustainable Yield, or extreme reference point, is adopted as management target and was proposed for adoption by these fisheries; in order to attain the target, gradual F reductions are required to restore stock biomass in eight fisheries, and a slight increase of F in one case. La langosta Panulirus argus (Latreille, 1804) constituye la pesqueria mas importante del Caribe: se capturan cerca de 42,000 toneladas. La evidencia sugiere que la alta mortalidad por pesca (F) podria haber provocado la sobre explotacion de la mayoria de las poblaciones. Las pesquerias mas importantes fueron evaluadas, proporcionando las bases para una explotacion sustentable en nueve paises que la explotan. Se evaluaron los parametros de las poblaciones y cada pesqueria fue simulada; la estructura por edades fue reconstruida vinculando las variables biologicas, economicas y sociales. Los resultados sugieren que se requiere de un manejo informado para mejorar los niveles de reclutamiento y recuperar la mayoria de las poblaciones. De las nueve pesquerias analizadas en detalle, se encontro que la de las Bahamas el principal productor, esta ligeramente sobreexplotada y otras cuatro se encuentran en un grado de sobreexplotacion que va de moderado a severo. Se identifico un valor arbitrario de F, mas bajo que el requerido para el nivel de Rendimiento Maximo Sostenible que es un punto de referencia extremo y se propone aqui como objetivo de manejo para estas pesquerias; para el logro de ese objetivo, es necesario reducir gradualmente la F en ocho pesquerias para que sus biomasas se restablezcan y en un caso implica un ligero aumento de la F.]

External description of the embryonic development of the prawn, macrobrachium americanum bate, 1868 (decapoda, palaemonidae) based on the staging method

Abstract: The embryonic changes during the development of the freshwater prawn, Macrobrachium americanum are described from observations made on live embryos based on the percentage-staging method. Eggs were observed with a stereomicroscope to obtain descriptions of embryonic periods. This prawn has an incubation time of 18 days at 24°C. Ten periods are described and illustrated. A comparison of this developmental process with those of congeneric species is included. Se describen los caracteres externos del desarrollo embrionario del langostino dulceacuicola Macrobrachium americanum tomando como criterio el metodo de estadios fijos basado en porcentajes. Los huevecillos fueron observados en vivo con un microscopio estereoscopico y se descibe cada periodo de desarrollo. Los huevecillos tardan 18 dias en incubarse a una temperatura de 24°C. Diez periodos se describen e ilustran. Se compara el desarrollo con el de algunas especies cercanas.

A Review of Recently Described Epibioses of Ciliate Protozoa on Crustacea

Abstract: An account of the Ciliata (Protozoa) recently described as epibionts on crustaceans is given herein. Eighty-seven species of ciliates are included, with indication of their taxonomic position, the basibiont crustacean species, and the localities were these epibiontic phenomena have been recorded. This overview actualizes the study of epibiosis in the Crustacea and could be of help in future research. Se proporciona una compilacion de los Ciliata (Protozoo) recientemente descritos como epibiontes de crustaceos. Ochenta y siete especies de ciliados son incluidas, con indicacion de su posicion taxonomica, las especies de crustaceos basibiontes, y las localidades donde estos fenomenos epibioticos han sido observados. Esta revision actualiza el estudio de la epibiosis en los Crustacea y puede ser de utilidad en futuras investigaciones.

Estimated Molecular Phylogenetic Relationships of Six Siphonostomatoid Families (Copepoda) Symbiotic on Elasmobranchs

Abstract: Members of the Siphonostomatoida are associated with either invertebrates or vertebrates. Even though the interfamilial relationships within the Siphonostomatoida are unresolved, it has generally been assumed that those members parasitic on vertebrates form a derived and monophyletic group. Eleven of the families symbiotic on vertebrates have been reported from elasmobranchs. One nuclear genetic marker (18S rDNA) and two partial mitochondrial markers (16S rDNA and COI) were used to estimate the phylogenetic relationship among six families symbiotic on elasmobranchs. The estimated molecular topologies using maximum likelihood, parsimony (unweighted and weighted), and Bayesian analyses are mostly similar. The six families investigated grouped into two major clades, with Kroyeriidae, Caligidae, Pandaridae, and Dichelestiidae in one clade, and Eudactylinidae and Sphyriidae in the other. The molecular topologies are compared with the previous morphological topology and present some support for some of the proposed relationships and alternative hypotheses in the areas of conflict. Valuable information obtained from the study is the indication that the genes used are informative at this level of investigation and can therefore be used in more elaborate future studies.

Population Biology and Reproduction of Kalliapseudes Schubartii Mañé-Garzón, 1949 (Peracarida, Tanaidacea) in a Tropical Coastal Lagoon, Itaipu, Southeastern Brazil

Abstract: [A population of the tanaidacean, Kalliapseudes schubartii Mane-Garzon, 1949 was sampled monthly in order to study its life cycle in a southeastern Brazilian tropical lagoon. The species' density changed seasonally, increasing in the beginning of the wet season and presenting peaks following precipitation peaks in other periods. Density changed due to oscillations in numbers of larval stages and juveniles. Females were larger than males, and the size at onset of sexual maturity of females was 5.9 mm. The sex-ratio was female-skewed during all months, in accordance with studies of the same species at other sites along the Brazilian coast and on other species of tanaids. Ovigerous females and other developmental stages were observed in all samples. Peaks in the frequencies of larval stages and juveniles were followed by peaks in ovigerous female frequency. Comparisons of populations of K. schubartii at different sites along the Brazilian coast showed an intraspecific difference in their life cycles according to a latitudinal gradient, with longer reproductive activity occurring in the tropics. [Les etudes de biologie des populations des especes-proies fournissent des informations utiles pour la gestion de la ressource et aident a prevoir les changements a venir concernant les especes exploitees commercialement.] Une population de tanaidaces Kalliapseudes schubartii Mane-Garzon, 1949 a ete echantillonnee mensuellement dans une lagune tropicale du sud-est du Bresil afin d'etudier son cycle de vie. Les resultats montrent une variation saisonniere de la densite, celle-ci augmentant au debut de la saison des pluies et presentant des pics a la suite des precipitations pour les autres periodes de l'annee. Les densites mesurees varient avec le changement de stade larvaire a juvenile. Les femelles sont plus grandes que les individus mâles, la taille de celles-ci au debut de la maturite sexuelle est de 5,9 mm. Le «sex-ratio» apparait desequilibre pour chaque mois avec une predominance des individus femelles, ce qui concorde avec des etudes realisees chez la meme espece sur d'autres sites le long de la cote bresilienne ainsi que chez d'autres especes de tanaidaces. Des femelles ovigeres ainsi qu'a d'autres stades de developpement ont ete observees dans tous les echantillons. Les pics de frequence concernant les stades larvaires et les individus juveniles sont suivis par des pics de frequence des femelles ovigeres. Enfin, la comparaison avec des populations de K. schubartii de differents endroits de la cote bresilienne a montre une difference intraspecifique dans leurs cycles de vie selon un gradient de latitude, avec une activite reproductrice plus longue sous les tropiques. , A population of the tanaidacean, Kalliapseudes schubartii Mane-Garzon, 1949 was sampled monthly in order to study its life cycle in a southeastern Brazilian tropical lagoon. The species' density changed seasonally, increasing in the beginning of the wet season and presenting peaks following precipitation peaks in other periods. Density changed due to oscillations in numbers of larval stages and juveniles. Females were larger than males, and the size at onset of sexual maturity of females was 5.9 mm. The sex-ratio was female-skewed during all months, in accordance with studies of the same species at other sites along the Brazilian coast and on other species of tanaids. Ovigerous females and other developmental stages were observed in all samples. Peaks in the frequencies of larval stages and juveniles were followed by peaks in ovigerous female frequency. Comparisons of populations of K. schubartii at different sites along the Brazilian coast showed an intraspecific difference in their life cycles according to a latitudinal gradient, with longer reproductive activity occurring in the tropics. [Les etudes de biologie des populations des especes-proies fournissent des informations utiles pour la gestion de la ressource et aident a prevoir les changements a venir concernant les especes exploitees commercialement.] Une population de tanaidaces Kalliapseudes schubartii Mane-Garzon, 1949 a ete echantillonnee mensuellement dans une lagune tropicale du sud-est du Bresil afin d'etudier son cycle de vie. Les resultats montrent une variation saisonniere de la densite, celle-ci augmentant au debut de la saison des pluies et presentant des pics a la suite des precipitations pour les autres periodes de l'annee. Les densites mesurees varient avec le changement de stade larvaire a juvenile. Les femelles sont plus grandes que les individus mâles, la taille de celles-ci au debut de la maturite sexuelle est de 5,9 mm. Le «sex-ratio» apparait desequilibre pour chaque mois avec une predominance des individus femelles, ce qui concorde avec des etudes realisees chez la meme espece sur d'autres sites le long de la cote bresilienne ainsi que chez d'autres especes de tanaidaces. Des femelles ovigeres ainsi qu'a d'autres stades de developpement ont ete observees dans tous les echantillons. Les pics de frequence concernant les stades larvaires et les individus juveniles sont suivis par des pics de frequence des femelles ovigeres. Enfin, la comparaison avec des populations de K. schubartii de differents endroits de la cote bresilienne a montre une difference intraspecifique dans leurs cycles de vie selon un gradient de latitude, avec une activite reproductrice plus longue sous les tropiques. ]

First record of Orconectes rusticus (Girard, 1852) (Decapoda, Cambaridae) west of the Great Continental Divide in North America

Abstract: Orconectes rusticus (Girard, 1852), known as the rusty crayfish, have spread over the last 50 years from their historical range in the Ohio River drainage, United States, to waters throughout much of 18 additional eastern and central states, provinces of Ontario and Qu?bec in Canada, and the Laurentian Great Lakes (Hobbs et al., 1989; Olden et al., 2006; Taylor et al., 2007). O. rusticus are omni vores and aggressive, resulting in numerous ecological and evolutionary impacts manifested across entire food webs. The invasion of this species has been associ ated with negative effects on aquatic plants, invertebrates, snails, and fishes (e.g., Olsen et al., 1991; Lodge et al., 1994; McCarthy et al., 2006), in addition to dis placing and hybridizing with native crayfish (e.g., Perry et al., 2001). The most westward reported occurrences of O. rusticus are the North Platte River near Dou glas, Wyoming (where the population is believed to have been successfully eradi cated) and Conchas Lake in north-east New Mexico (Bouchard, 1977). Preventing the westward spread of aquatic nuisance species from eastern North America is a primary goal of the 100th Meridian Initiative (http://www.100thmeridian.org). Here we are the first to document the presence of O. rusticus west of the Continental Divide in North America, separating watersheds that drain into the Pacific Ocean from those river systems that drain into the Atlantic Ocean. On 19 July 2005, a field survey conducted by the Xerces Society for Invertebrate Conservation and the Confederated Tribes of Warm Springs Reservation of Oregon revealed the occurrence of a non-native Orconectes sp. crayfish in the upper

Interactions with fishes of five species of Lysmata (Decapoda, Caridea, Lysmatidae)

Abstract: Species of Lysmata, commonly called peppermint shrimp, rock shrimp or cleaner shrimp; inhabit rocks, coral reefs, or shipwrecks from the intertidal zone to the continental shelf in tropical and warm temperate seas. At least 11 species have been reported to be cleaners: species that remove debris, dead or injured tissue, parasites, or fungi from a larger animal (the client, usually a fish) and are allowed by the client to do so without being attacked or harmed (C?t?, 2000). This behavior often is considered to be mutualistic: the cleaner receives a meal, and the client is freed from irritants or parasites. Limbaugh et al. (1961) divided cleaner shrimps into two groups on the basis of behavior. One group contained species that usually were pair forming or soli tary, territorial, brightly marked, and tropical. These species tended to be highly dependent on their "hosts" for food, and displayed themselves to their hosts in a conspicuous manner. The other group, comprised of Lysmata californica (Stimp son, 1866) (as Hippolysmata calif ornica), contained shrimp that are gregarious, wandering, and omnivorous, not highly dependent on its host for survival and not known to display themselves to attract fishes. This behavioral pattern was thought to be a more "primitive" type of cleaning behavior. C?t? (2000) distinguished be tween "facultative" cleaners, which obtain only a "small part" of their food by cleaning, and "obligate" cleaners, which obtain "on average 85%" of their food from client-gleaned items. Because the stomach contents of only a few reputed cleaners have been studied, this distinction is not very useful. Bauer (2004) distinguished between "imperfect", "transitional" and "highly evolved", or "specialized" cleaners. The first group, containing L. californica, Lysmata wurdemanni (Gibbes, 1850) and Lysmata seticaudata (Risso, 1816), has the same features as described by Limbaugh et al. (1961). These shrimp engage

Relative growth and sexual maturity of the spider crab, Mithrax tortugae Rathbun, 1920 (Brachyura, Mithracidae) on a continental island off the southeastern Brazilian coast

Abstract: Relative growth can be understood as a morphometric relationship of body parts with the body as a whole, described by a mathematic equation. This study provides information on the patterns of relative growth of Mithrax tortugae from Vitoria Island, southeastern Brazilian coast (23°44′04″S 45°01′35″W). Crabs were obtained from monthly collections by hand during SCUBA diving, between January 2004 and February 2007. A total of 168 crabs was obtained, 64 males and 104 females. Regression analysis was performed among carapace width (CW), as the independent variable, and carapace length (CL), abdomen width (AW), height high and length of the propodus (PH and PL), and gonopod length (GL) as dependent variables, using the power function y = a x b . Young males showed positive allometry with regard to gonopod growth. Abdomen growth of juvenile females was also positively allometric. The growth patterns recorded for M. tortugae are associated with the species reproductive strategy, i.e., preparation of body parts involved in gamete transfer and egg clutch storage, like the male gonopods and the female abdomen. According to the results obtained, morphological maturity is attained at 12.95 mm CW for males and at 22.40 mm CW for females. The general patterns shown by M. tortugae are similar to the model adopted for Brachyura in general. Crescimento relativo pode ser entendido como a analise das relacoes entre dimensoes de partes do corpo em funcao do corpo como um todo, descrita por uma equacao matematica. Este estudo fornece informacoes sobre os padroes de crescimento relativo do Mithrax tortugae , de uma populacao da Ilha da Vitoria, sudeste do litoral brasileiro (23°44′04″S 45°01′35″W). Os caranguejos foram obtidos manualmente, a partir de coletas mensais, por meio de mergulho autonomo, entre janeiro de 2004 e fevereiro de 2007. Um total de 168 caranguejos foi obtido, 64 machos e 104 femeas. Foram executadas regressoes entre a largura da carapaca (LC), variavel independente e o comprimento da carapaca (CC), largura do abdomen (LA) e altura e comprimento do propodo quelar (APQ e CPQ), como variaveis dependentes, aplicando a funcao potencia y = a x b . Os machos jovens apresentaram alometria positiva para o crescimento do gonopodio. Enquanto que para nas femeas jovens foi registrado um padrao alometrico positivo para o crescimento do abdomen. Os padroes de crescimento registrados para M. tortugae estao associados com a estrategia reprodutiva da especie, ou seja, a preparacao das partes do corpo envolvidas com a transferencia de gametas e a incubacao dos ovos, como os gonopodios para os machos e o abdomen para as femeas. De acordo com os resultados obtidos, a maturidade morfologica e atingida em 12,95 mm LC para os machos e em 22,40 mm LC para as femeas. Os padroes gerais demonstrados por M. tortugae seguem o modelo geral descrito para os Brachyura.

Sexual maturity and reproductive strategy of the rock crab grapsus adscensionis (osbeck, 1765) (brachyura, grapsidae) on ascension island

Abstract: The rock crab, Grapsus adscensionis (Osbeck, 1765), was studied on Ascension Island, South Atlantic Ocean. By day crabs were inactive above water level at high tide, but during low tide fed on algal films exposed on the low shore. By night they were inactive at all tidal states. Both sexes reached a maximum carapace width of 74 mm, but were potentially capable of further moulting. Sexual maturity was reached at ∼38 mm carapace width in males, and ∼43 mm carapace width in females. In females one batch of eggs was produced in most intermoults. The ovaries had matured by the time that the eggs had completed incubation. The females moulted shortly after the hatching of the eggs, and re-laid early in the next intermoult. Consequently 78% of mature females were ovigerous. It is estimated that an egg batch is laid every 24 days. Reproductive investment (dry weight) per egg batch averaged 5.5%. Le crabe des rochers Grapsus adscensionis (Osbeck, 1765), a ete etudie sur l'ile d'Ascencion, ocean Atlantique Sud. De jour, les crabes sont inactifs au dessus du niveau de l'eau a maree haute, mais durant la maree basse ils se nourrissent sur le film algal de la cote emergee. La nuit ils sont inactifs quelle que soit la maree. Les deux sexes ont atteint une taille maximum de 74 mm de largeur de carapace, mais sont susceptibles de continuer a muer. La maturite sexuelle est atteinte a ∼38 mm de largeur de carapace pour les mâles, et ∼43 mm pour les femelles. Chez les femelles, une ponte est emise dans la plus part des intermues. Les ovaires sont matures au moment ou les œufs terminent leur incubation. Les femelles muent rapidement apres l'eclosion des œufs et pondent a nouveau au debut de l'intermue suivante. En consequence 78% des femelles mâtures sont ovigeres. Il est estime qu'une ponte est emise tous les 24 jours. L'investissement dans la reproduction (en poids sec) par portee est en moyenne de 5,5%.

The role of the major chelae in the localization and sampling of female odours by male crayfish, Orconectes rusticus (Girard, 1852)

Abstract: [Research has shown that the major chelae of male crayfish, Orconectes rusticus, are important chemosensory appendages and may aid in the perception and discrimination of female odours. However, it is unclear whether the major chelae are important for localization of female odour sources. In this study, we examined the role of sensory information from the major chelae in the localization and discrimination of conspecific female odours. We analysed the behavioural reactions of form I male crayfish to two different odour treatments: reproductive female-conditioned water or water (controls) delivered from one end of a test arena. Also, all male crayfish either had their chelae intact or sensory blocked. We measured locomotory behaviours in response to odours and chelae treatments. In addition, behaviours performed at the source of the odour were quantified. Male crayfish with intact chelae spent more time closer to a reproductive female odour source, whereas crayfish with blocked chelae showed no preference. There was no response to water. Male crayfish demonstrated differences in chelae waving and other local behaviours in response to female odours. These results suggest that the major chelae are important sensory structures, which aid in the localization and discrimination of female odours. Des recherches ont montre que la pince principale de l'ecrevisse mâle Orconectes rusticus est un important appendice chemorecepteur et pourrait aider a la perception et la discrimination des odeurs des femelles. Cependant, il n'est pas clair si la pince principale est importante pour la localisation de la source des odeurs femelles. Dans cette etude, nous avons examine le role de la pince principale dans l'information sensorielle comme la localisation et la discrimination des odeurs femelles con-specifiques. Nous avons analyse le comportement de la forme I des mâles d'ecrevisse a deux differents traitements olfactifs: de l'eau de femelles conditionnees a la reproduction ou de l'eau (controle) provenant de la fin de la zone de test. De plus toutes les ecrevisses mâles avaient soit leur pince intacte ou sensoriellement bloquee. Nous avons mesure le comportement de locomotion en reponse aux traitements odorants et de la pince. De plus les comportements effectues a la source de l'odeur ont ete quantifies. Les mâles avec une pince intacte passent plus de temps pres de la source d'odeur de femelles en reproduction, tandis que les ecrevisses avec des pinces bloquees ne montrent aucune preference. Il n'y a eu aucune reponse a l'eau temoin. Les mâles d'ecrevisse demontrent des differences dans le mouvement des pinces et d'autres comportements locaux en reponse a l'odeur des femelles. Ces resultats suggerent que les pinces principales sont des structures sensorielles importantes, qui pourraient aider a la localisation et la discrimination des odeurs des femelles., Research has shown that the major chelae of male crayfish, Orconectes rusticus, are important chemosensory appendages and may aid in the perception and discrimination of female odours. However, it is unclear whether the major chelae are important for localization of female odour sources. In this study, we examined the role of sensory information from the major chelae in the localization and discrimination of conspecific female odours. We analysed the behavioural reactions of form I male crayfish to two different odour treatments: reproductive female-conditioned water or water (controls) delivered from one end of a test arena. Also, all male crayfish either had their chelae intact or sensory blocked. We measured locomotory behaviours in response to odours and chelae treatments. In addition, behaviours performed at the source of the odour were quantified. Male crayfish with intact chelae spent more time closer to a reproductive female odour source, whereas crayfish with blocked chelae showed no preference. There was no response to water. Male crayfish demonstrated differences in chelae waving and other local behaviours in response to female odours. These results suggest that the major chelae are important sensory structures, which aid in the localization and discrimination of female odours. Des recherches ont montre que la pince principale de l'ecrevisse mâle Orconectes rusticus est un important appendice chemorecepteur et pourrait aider a la perception et la discrimination des odeurs des femelles. Cependant, il n'est pas clair si la pince principale est importante pour la localisation de la source des odeurs femelles. Dans cette etude, nous avons examine le role de la pince principale dans l'information sensorielle comme la localisation et la discrimination des odeurs femelles con-specifiques. Nous avons analyse le comportement de la forme I des mâles d'ecrevisse a deux differents traitements olfactifs: de l'eau de femelles conditionnees a la reproduction ou de l'eau (controle) provenant de la fin de la zone de test. De plus toutes les ecrevisses mâles avaient soit leur pince intacte ou sensoriellement bloquee. Nous avons mesure le comportement de locomotion en reponse aux traitements odorants et de la pince. De plus les comportements effectues a la source de l'odeur ont ete quantifies. Les mâles avec une pince intacte passent plus de temps pres de la source d'odeur de femelles en reproduction, tandis que les ecrevisses avec des pinces bloquees ne montrent aucune preference. Il n'y a eu aucune reponse a l'eau temoin. Les mâles d'ecrevisse demontrent des differences dans le mouvement des pinces et d'autres comportements locaux en reponse a l'odeur des femelles. Ces resultats suggerent que les pinces principales sont des structures sensorielles importantes, qui pourraient aider a la localisation et la discrimination des odeurs des femelles.]

Intertidal thalassinidean shrimps (Thalassinidea, Callianassidae and Upogebiidae) of the west coast of Baja California, Mexico: annotated checklist, key for identification, and symbionts

Abstract: [An annotated checklist of the intertidal species of Thalassinidea of the west coast of Baja California, Mexico, and an updated comparative list of their commensals and parasites that live inside the burrows of these crustaceans or on their body, is provided. Four species of burrower shrimps, the mud shrimp, Upogebia macginiteorum (Williams, 1986) [Upogebiidae] and the ghost shrimps, Neotrypaea biffari (Holthuis, 1991), N. californiensis (Dana, 1854), and N. gigas (Dana, 1852) [Callianassidae] were collected during our survey. For each species, the diagnostic features, distribution, and some ecological remarks are recorded, which include: (1) a revised diagnoses for the Neotrypaea species; (2) a range extension for N. californiensis and N. gigas from San Quintin Bay, Baja California, Mexico to El Coyote Estuary, near Point Abreojos, Baja California Sur, Mexico; (3) nine new records of symbiotic associations; and (4) the first record for Mexico of the commensal copepod, Clausidium vancouverense (Haddon, 1912). An illustrated key to the identification of the intertidal species of thalassinideans of the Californian Province is included as well. El presente estudio proporciona una lista faunistica comentada de las especies de Talasinidos intermareales de la costa oeste de Baja California, Mexico, y una lista comparativa actualizada de los comensales y parasitos que viven dentro de la madriguera de estos crustaceos o sobre su cuerpo. Cuatro especies de camarones amadrigadores fueron recolectados durante nuestro estudio, el camaron de fango Upogebia macginiteorum (Williams, 1986) [familia Upogebiidae] y los camarones fantasma Neotrypaea biffari (Holthuis, 1991), N. californiensis (Dana, 1854) y N. gigas (Dana, 1852) [familia Callianassidae]. Para cada especie, las caracteristicas diagnosticas, la distribucion y algunas observaciones ecologicas son registradas, lo cual incluye: (1) una diagnosis revisada para las especies de Neotrypaea ; (2) la extension del ambito geografico para N. californiensis y N. gigas de la Bahia de San Quintin, Baja California, Mexico hasta el estero El Coyote, cerca de Punta Abreojos, Baja California Sur, Mexico; (3) el registro de nueve nuevas asociaciones simbioticas y (4) el primer registro para Mexico del copepodo comensal Clausidium vancouverense (Haddon, 1912). Se incluye tambien una clave de identificacion de las especies de talasinidos intermareales de la provincia Californiana. , An annotated checklist of the intertidal species of Thalassinidea of the west coast of Baja California, Mexico, and an updated comparative list of their commensals and parasites that live inside the burrows of these crustaceans or on their body, is provided. Four species of burrower shrimps, the mud shrimp, Upogebia macginiteorum (Williams, 1986) [Upogebiidae] and the ghost shrimps, Neotrypaea biffari (Holthuis, 1991), N. californiensis (Dana, 1854), and N. gigas (Dana, 1852) [Callianassidae] were collected during our survey. For each species, the diagnostic features, distribution, and some ecological remarks are recorded, which include: (1) a revised diagnoses for the Neotrypaea species; (2) a range extension for N. californiensis and N. gigas from San Quintin Bay, Baja California, Mexico to El Coyote Estuary, near Point Abreojos, Baja California Sur, Mexico; (3) nine new records of symbiotic associations; and (4) the first record for Mexico of the commensal copepod, Clausidium vancouverense (Haddon, 1912). An illustrated key to the identification of the intertidal species of thalassinideans of the Californian Province is included as well. El presente estudio proporciona una lista faunistica comentada de las especies de Talasinidos intermareales de la costa oeste de Baja California, Mexico, y una lista comparativa actualizada de los comensales y parasitos que viven dentro de la madriguera de estos crustaceos o sobre su cuerpo. Cuatro especies de camarones amadrigadores fueron recolectados durante nuestro estudio, el camaron de fango Upogebia macginiteorum (Williams, 1986) [familia Upogebiidae] y los camarones fantasma Neotrypaea biffari (Holthuis, 1991), N. californiensis (Dana, 1854) y N. gigas (Dana, 1852) [familia Callianassidae]. Para cada especie, las caracteristicas diagnosticas, la distribucion y algunas observaciones ecologicas son registradas, lo cual incluye: (1) una diagnosis revisada para las especies de Neotrypaea ; (2) la extension del ambito geografico para N. californiensis y N. gigas de la Bahia de San Quintin, Baja California, Mexico hasta el estero El Coyote, cerca de Punta Abreojos, Baja California Sur, Mexico; (3) el registro de nueve nuevas asociaciones simbioticas y (4) el primer registro para Mexico del copepodo comensal Clausidium vancouverense (Haddon, 1912). Se incluye tambien una clave de identificacion de las especies de talasinidos intermareales de la provincia Californiana. ]

Selectivity of Square and Hexagonal Mesh Codends for the Deep Water Rose Shrimp, Parapenaeus Longirostris (Lucas, 1846) (Decapoda, Penaeidae) in the Aegean Sea

Abstract: [This study aims to assess the selectivity of square and hexagonal mesh codends for the deep water rose shrimp, Parapenaeus longirostris Experiments were conducted in Kusadasi Bay and Sigacik Bay, eastern Aegean Sea, between 30 September and 25 October 2007 with a commercial stern trawler The covered codend technique was used for controlling the escapees and selectivity parameters were estimated by maximum likelihood over a logistic model The selectivity parameters for individual hauls were estimated using the software CC2000, whereas mean selection curves of the codends were estimated by using Fryer's model, taking into account the between-haul variation using the ECModeller software The mean fifty percent retention length (L50) values of square and hexagonal mesh codends were estimated as 167 mm ± 007 and 174 mm ± 005, respectively Selection range (SR) values were 65 mm ± 011 in square and 62 mm ± 015 in hexagonal mesh codend Although L50 and SR values of the two different mesh shape codends are close to one another, L50 values of neither codend provides a satisfactory selection, considering the 21 mm length at first maturity (LFM) of this species However, the hexagonal mesh codend can be used as an alternative for the same mesh size diamond mesh codend in targeted rose shrimp trawl fishery Cette etude a pour but d'evaluer la selectivite des culs de chalut a maille carree et a maille hexagonale utilises pour la crevette rose d'eau profonde Parapenaeus longirostris Des experimentations ont ete menees dans la baie de Kusadasi et dans la baie de Sigacik, a l'est de la mer Egee, entre le 30 septembre et le 25 octobre 2007 avec un chalutier commercial de peche arriere La technique du cul de chalut "couvert" a ete utilisee pour controler les echappees et les parametres de selectivite ont ete estimes par maximum de vraisemblance a l'aide d'un modele logistique Les parametres de selectivite pour les filets individuels ont ete estimes a l'aide du logiciel CC2000, tandis que les courbes de selection moyennes des culs de chaluts etaient estimes en utilisant le modele de Fryer, en tenant compte des variations suivant les prises en utilisant le logiciel ECModeller Les valeurs moyennes de longueur a cinquante pour cent de retention (L50) des filets a maille carree et a maille hexagonale ont ete estimees a 16,7 mm ± 0,07 et 17,4 mm ± 0,05, respectivement Les valeurs de la selection (SR) etaient de 6,5 mm ± 0,11 pour la maille carree et 6,2 mm ± 0,15 pour les filets a maille hexagonale Bien que les valeurs de L50 et SR des filets de mailles differentes soient proches les unes des autres, les valeurs de L50 d'aucun des filets ne donne une valeur de selection satisfaisante, en considerant la longueur a premiere maturite (LFM) de 21 mm de cette espece Cependant, le cul de filet a maille hexagonale peut etre utilise comme une alternative au filet de meme taille de maille diamant pour la peche au chalut de la crevette rose, This study aims to assess the selectivity of square and hexagonal mesh codends for the deep water rose shrimp, Parapenaeus longirostris Experiments were conducted in Kusadasi Bay and Sigacik Bay, eastern Aegean Sea, between 30 September and 25 October 2007 with a commercial stern trawler The covered codend technique was used for controlling the escapees and selectivity parameters were estimated by maximum likelihood over a logistic model The selectivity parameters for individual hauls were estimated using the software CC2000, whereas mean selection curves of the codends were estimated by using Fryer's model, taking into account the between-haul variation using the ECModeller software The mean fifty percent retention length (L 50) values of square and hexagonal mesh codends were estimated as 167 mm ± 007 and 174 mm ± 005, respectively Selection range (SR) values were 65 mm ± 011 in square and 62 mm ± 015 in hexagonal mesh codend Although L 50 and SR values of the two different mesh shape codends are close to one another, L 50 values of neither codend provides a satisfactory selection, considering the 21 mm length at first maturity (LFM) of this species However, the hexagonal mesh codend can be used as an alternative for the same mesh size diamond mesh codend in targeted rose shrimp trawl fishery Cette etude a pour but d'evaluer la selectivite des culs de chalut a maille carree et a maille hexagonale utilises pour la crevette rose d'eau profonde Parapenaeus longirostris Des experimentations ont ete menees dans la baie de Kusadasi et dans la baie de Sigacik, a l'est de la mer Egee, entre le 30 septembre et le 25 octobre 2007 avec un chalutier commercial de peche arriere La technique du cul de chalut "couvert" a ete utilisee pour controler les echappees et les parametres de selectivite ont ete estimes par maximum de vraisemblance a l'aide d'un modele logistique Les parametres de selectivite pour les filets individuels ont ete estimes a l'aide du logiciel CC2000, tandis que les courbes de selection moyennes des culs de chaluts etaient estimes en utilisant le modele de Fryer, en tenant compte des variations suivant les prises en utilisant le logiciel ECModeller Les valeurs moyennes de longueur a cinquante pour cent de retention (L 50) des filets a maille carree et a maille hexagonale ont ete estimees a 16,7 mm ± 0,07 et 17,4 mm ± 0,05, respectivement Les valeurs de la selection (SR) etaient de 6,5 mm ± 0,11 pour la maille carree et 6,2 mm ± 0,15 pour les filets a maille hexagonale Bien que les valeurs de L 50 et SR des filets de mailles differentes soient proches les unes des autres, les valeurs de L 50 d'aucun des filets ne donne une valeur de selection satisfaisante, en considerant la longueur a premiere maturite (LFM) de 21 mm de cette espece Cependant, le cul de filet a maille hexagonale peut etre utilise comme une alternative au filet de meme taille de maille diamant pour la peche au chalut de la crevette rose]

Morphological maturity of the knobbed spider crab, leurocyclus tuberculosus (h. milne edwards & lucas, 1842) (brachyura, majidae) in the northern patagonian gulfs

Abstract: Sexual maturation in brachyurans has three different components: physiological, morphological, and functional. The second is visualized by examining changes in the morphometric relationships between some dimensions of the organs involved in mating and &gg incubation, relative to a standard measure of size. Aiming to establish the size at morphological maturity for the Patagonian knobbed spider crab, Leurocyclus tuberculosas, a morphometric analysis was conducted on specimens sampled in the northern Patagonian gulfs (41?-43?S). Discontinuities were detected in In transformed relationships of abdomen width on carapace width of females, and right chela length on carapace width of males. For females, estimated CWmorph50% (carapace width at which 50% of the individuals attains morphometric maturity) was 47.9 mm, and CW of the smallest ovigerous female observed in the samples was 42.7 mm. For males, a change in the growth rate of ln(ChL) relative to ln(CW) was detected at 48.9 mm CW.

Some Biological Aspects of Parapenaeus Longirostris (Lucas, 1846) (Decapoda, Dendrobranchiata) in the Gulf of Alicante (S.E. Spain)

Abstract: The deep water rose shrimp, Parapenaeus longirostris is a commercial species for the trawl fleet that operates in the Gulf of Alicante. Despite its importance, there were no biological studies on the species for that area. This study presents results on the life cycle of the species, shedding light on certain crucial aspects. Data were obtained from monthly samples taken from commercial catches landed in the port of Santa Pola from 2001 to 2006. The fisheries in the studied area show a decreasing trend, both in number of vessels targeted on the species, and in landings, since 2001. The species shows a sexual size dimorphism, with a negative allometry of relative growth that is more pronounced in males and thus results in lower sizes of males than of females. Estimate produced from VBGF parameters gave higher K values for males than for females, indicating that males would reach 13.2 mm CL in the first year and females 14.8 mm CL, which would represent a maximum life expectancy of 4 and 6 years, respectively. The reproductive period, based on the percentages of maturity and GSI development, was found to range throughout the year, with some peaks of activity especially in summer. The size at first maturity (L50) of 25.6 mm for females indicates that maturation will have to occur from the second year of life. La gamba blanca Parapenaeus longirostris es una especie comercial para la flota de arrastre que opera en el Golfo de Alicante. A pesar de su importancia, no existian estudios sobre la biologia de la especie en esta area. Este trabajo presenta resultados sobre el ciclo vital de la especie, aclarando algunos aspectos importantes. Los datos fueron obtenidos a partir de muestreos mensuales realizados sobre capturas comerciales desembarcadas en el puerto de Santa Pola durante los anos 2001 al 2006. La pesqueria en el area de estudio muestra una tendencia a la disminucion, tanto en el numero de embarcaciones dedicadas a su captura como de sus desembarcos, desde 2001. Los resultados muestran un dimorfismo de tallas por sexos, con una alometria negativa de crecimiento, mas destacada en los machos que alcanzan tallas menores que las hembras. Las estimaciones realizadas de los parametros de la VBGF dan unos valores de K mas elevados en machos que en hembras, con lo que los machos alcanzarian los 13,2 mm de CL en el primer ano y las hembras los 14,8 mm de CL en el mismo tiempo, lo que podria representar una esperanza de vida de cuatro y seis anos respectivamente. La epoca de reproduccion se ha definido en base a los porcentajes de madurez y la evolucion del IGS, desarrollandose a lo largo de todo el ano, con especial intensidad en primavera-verano y en otono. Las tallas de primera madurez (L50) de 25,6 mm para hembras, indican que la maduracion tendria lugar a partir del segundo ano de vida.

Seasonal abundance, ecology, reproductive biology and biochemical composition of mesopodopsis orientalis w.m.tattersall (mysida) from a tropical estuary (cochin backwater) in india

Abstract: Seasonal abundance, life history, and biochemical composition of Mesopodopsis orientalis Tattersall were investigated based on samples collected over a period of one year in tropical estuary, i.e., Cochin backwater. M. orientalis was recorded throughout the year and its peak abundance was observed during the monsoon period. The species produced more than one generation per year. The number of embryos carried by a single female ranged from 7 to12, and was correlated with female length (P<0.05), tending to increase with the size of the female. Egg size varied between 0.39 and 0.47 mm, with no correlation with length of the female, and size difference was observed in the same brood. Males and females attain sexual maturity after reaching the total length of 5 mm and 4.5 mm respectively. With the exception of chlorophyll a, the environmental parameters, dissolved oxygen, salinity, pH and water temperature do not have much influence on population density. The biochemical composition of the species reveals its high nutritional quality. Matured males and females showed higher protein contents than other stages, while carbohydrate content was high in immature stages, and lipid content was high in brooding females.

Impact of Environmental Factors on Zonation, Abundance, and Other Biological Parameters of Two Tunisian Populations of Talitrus Saltator (Amphipoda, Talitridae)

Abstract: [Zonation, biology, and reproduction of two populations of Talitrus saltator (Amphipoda, Talitridae) were studied at two different beaches: Zouaraa and Korba, respectively, in the north and northeast of Tunisia. Sampling was carried out monthly or twice a month along a transect from the shoreline up to the dunes, from December 1998 to May 2000 at Zouaraa, and from December 2001 to December 2003 at Korba. Densities and mean zonations were calculated for each sampling period. Environmental factors (sand moisture, sand and air temperature, humidity, precipitation, wind direction and velocity, cloudiness, and atmospheric pressure) were simultaneously recorded and used to assess their influence on zonation, density, and other biological parameters of the species, notably the percentage of juveniles and the sex ratio. The two populations exhibited a similar zonation: a main distribution on the dunes in winter and near the shoreline in summer, and dispersion along the transect in autumn and spring. Moreover, juveniles occurred, in most cases, lower on the shore than adults, whereas no differences were observed between sexes. The two populations exhibited two different patterns of seasonal variation in density: at Zouaraa, the highest densities were recorded in winter and the lowest in summer, whereas at Korba, the population showed a totally opposite pattern. Furthermore, statistical analysis showed, from all the environmental parameters chosen, a main influence of temperature and sand moisture on the distribution and reproductive biology of Talitrus saltator. La zonation, la biologie et la reproduction de deux populations de Talitrus saltator (Amphipoda, Talitridae) ont ete etudiees dans deux sites differents, Zouaraa et Korba, respectivement, dans le nord et le nord-est de la Tunisie. Un echantillonnage mensuel ou semi-mensuel a ete effectue le long d'un transect depuis la ligne de rivage jusqu'au sommet des dunes, et ce a partir de decembre 1998 jusqu'a mai 2000 a Zouaraa et de decembre 2001 jusqu'a decembre 2003 a Korba. La densite et la zonation moyenne ont ete estimees pour chaque periode d'echantillonnage. Les facteurs environnementaux (temperatures et humidites du substrat et de l'air, precipitation, direction et vitesse du vent, nebulosite et pression atmospherique) ont ete simultanement enregistres et utilises afin d'apprehender leur influence sur la zonation, la densite ainsi que sur d'autres parametres biologiques de l'espece, notamment le pourcentage des jeunes, et le sex ratio. Les deux populations ont une zonation similaire: une distribution exclusivement au niveau des dunes en hiver et au niveau de la ligne de rivage en ete, avec une dispersion tout au long du transect d'echantillonnage en automne et au printemps. Par ailleurs, les jeunes ont une distribution beaucoup plus vers la ligne de rivage par rapport aux adultes, alors qu'il n'y a pas de differences entre les sexes. La variation saisonniere de la densite est tres diverse d'une population a l'autre; alors qu'a Zouaraa, les densites les plus elevees ont ete enregistrees en hiver et les plus faibles en ete, Korba montre un profil tout a l'oppose. De plus, les analyses statistiques ont mis en evidence, parmi les parametres environnementaux choisis, l'influence de la temperature de l'air et l'humidite relative du substrat sur la distribution et la biologie reproductive de Talitrus saltator., Zonation, biology, and reproduction of two populations of Talitrus saltator (Amphipoda, Talitridae) were studied at two different beaches: Zouaraa and Korba, respectively, in the north and northeast of Tunisia. Sampling was carried out monthly or twice a month along a transect from the shoreline up to the dunes, from December 1998 to May 2000 at Zouaraa, and from December 2001 to December 2003 at Korba. Densities and mean zonations were calculated for each sampling period. Environmental factors (sand moisture, sand and air temperature, humidity, precipitation, wind direction and velocity, cloudiness, and atmospheric pressure) were simultaneously recorded and used to assess their influence on zonation, density, and other biological parameters of the species, notably the percentage of juveniles and the sex ratio. The two populations exhibited a similar zonation: a main distribution on the dunes in winter and near the shoreline in summer, and dispersion along the transect in autumn and spring. Moreover, juveniles occurred, in most cases, lower on the shore than adults, whereas no differences were observed between sexes. The two populations exhibited two different patterns of seasonal variation in density: at Zouaraa, the highest densities were recorded in winter and the lowest in summer, whereas at Korba, the population showed a totally opposite pattern. Furthermore, statistical analysis showed, from all the environmental parameters chosen, a main influence of temperature and sand moisture on the distribution and reproductive biology of Talitrus saltator. La zonation, la biologie et la reproduction de deux populations de Talitrus saltator (Amphipoda, Talitridae) ont ete etudiees dans deux sites differents, Zouaraa et Korba, respectivement, dans le nord et le nord-est de la Tunisie. Un echantillonnage mensuel ou semi-mensuel a ete effectue le long d'un transect depuis la ligne de rivage jusqu'au sommet des dunes, et ce a partir de decembre 1998 jusqu'a mai 2000 a Zouaraa et de decembre 2001 jusqu'a decembre 2003 a Korba. La densite et la zonation moyenne ont ete estimees pour chaque periode d'echantillonnage. Les facteurs environnementaux (temperatures et humidites du substrat et de l'air, precipitation, direction et vitesse du vent, nebulosite et pression atmospherique) ont ete simultanement enregistres et utilises afin d'apprehender leur influence sur la zonation, la densite ainsi que sur d'autres parametres biologiques de l'espece, notamment le pourcentage des jeunes, et le sex ratio. Les deux populations ont une zonation similaire: une distribution exclusivement au niveau des dunes en hiver et au niveau de la ligne de rivage en ete, avec une dispersion tout au long du transect d'echantillonnage en automne et au printemps. Par ailleurs, les jeunes ont une distribution beaucoup plus vers la ligne de rivage par rapport aux adultes, alors qu'il n'y a pas de differences entre les sexes. La variation saisonniere de la densite est tres diverse d'une population a l'autre; alors qu'a Zouaraa, les densites les plus elevees ont ete enregistrees en hiver et les plus faibles en ete, Korba montre un profil tout a l'oppose. De plus, les analyses statistiques ont mis en evidence, parmi les parametres environnementaux choisis, l'influence de la temperature de l'air et l'humidite relative du substrat sur la distribution et la biologie reproductive de Talitrus saltator.]

Ovarian development stages of Callinectes danae and Callinectes ornatus (Brachyura, Portunidae)

Abstract: Along the Brazilian coast, Callinectes danae and Callinectes ornatus are very important species, both commercially and ecologically. The fishing pressure and the social and economic importance of the group justify the need for specific detailed information concerning the reproduction of each representative for the development of management actions. Histological procedures associated with a chromatic colour scale have pointed out four ovarian developmental stages to be distinguished in both species, classified as: stage-I (immature), stage-II (developing), stage-III (ripe), and stage-IV (spent). The presence of oocytes-I and oocytes-II in the stages "ripe" and "spent" indicates that spawning takes place with at least two lots of mature oocytes for both species. However, the possibility of a single spawning during critical situations of stress cannot be rejected. Ao largo da costa brasileira, Callinectes danae e Callinectes ornatus sao especies importantes comercialmente e ecologicamente. A pressao por pesca somada a importância social e economica do grupo justifica a necessidade de informacoes especificas detalhadas a respeito da reproducao de cada um para desenvolvimento de acoes de manejo. Procedimentos histologicos associados a uma escala cromatica de cores distinguiu quatro estagios de desenvolvimento gonadal, classificados como: estagio-I (imaturo), estagio-II (desenvolvimento), estagio-III (maduro) e estagio-IV (desovado). A presenca de ovocitos-I e ovocitos-II nos estagios "maduro" e "desovado" indica uma desova em pelo menos dois lotes de ovocitos maduros para ambas as especies. No entanto, a possibilidade de uma desova simples em situacoes criticas de estresse nao deve ser rejeitada.

The first record of the Jinga shrimp, Metapenaeus affinis (H. Milne Edwards, 1837) (Decapoda, Penaeidae) from the Mediterranean Sea

Abstract: Of the nearly 600 alien marine species of Metazoa that have been recorded in the Mediterranean Sea, two-thirds have established durable populations of ever larger range (Galil, 2008a, b). The majority of the aliens originate from the Indo Pacific region and have entered the Mediterranean through the Suez Canal (Ery threan aliens). Nine species of alien penaeid prawns occur in the Levant Basin, eastern Mediterranean, all of them known from the Turkish coast: Marsupenaeus japonicus (Bate, 1888), Metapenaeus monoceros (Fabricius, 1798), Penaeus semi sulcatus De Haan, 1844, Melicertus hathor (Burkenroad, 1959), Metapenaeop sis aegyptia Galil, 1990, Metapenaeopsis mogiensis consobrina (Nobili, 1904), Metapenaeus stebbingi (Nobili, 1904), Trachysalambria palaestinensis (Steinitz, 1932), and Fenneropenaeus merguiensis (De Man, 1888) (cf. Galil, 2008a, b). All the alien penaeids but one (E merguiensis) have entered the Mediterranean through the Suez Canal. The first three species are highly valued commercially and consti tute most of the prawn catch off southeastern Turkey (Duruer et al., 2008). Extensive studies conducted in 2003-2005 of the commercial prawn trammel net fishery targeting the native Mediterranean prawn, Melicertus kerathurus (Forsk?l, 1775) in Izmir Bay, have revealed no alien prawns, either in the landed catch or in the discard (Gok?e & Metin, 2007; Akyol, 2008).

Sandimenes nov gen., for periclimenes hirsutus bruce, 1971 (decapoda, caridea, pontoniinae)

Abstract: A new genus, Sandimenes nov. gen., is established for Periclimenes hirsutus Bruce, 1971a based mainly on its unusual character of the dense, long tufts of setae on the ventral surface of the ambulatory propodi, and the general hirsuteness of the body and appendages. The genera erected or removed from the synonymy of Periclimenes after Bruce's (1994) monograph on the Indo-West Pacific genera of the Pontoniinae are reviewed, and a key to those genera closely similar to Periclimenes is provided.

Comparison between the catch composition of the French and ORE type beam trawls on deep-sea decapod crustaceans: implications for quantitative sampling of the deep-sea decapod biodiversity

Abstract: [The French beam trawl and the ORE beam trawl are common research sampling gears for deep-sea biodiversity. The French beam trawl is equipped with a tickler chain and a pair of iron sides. The ORE beam trawl has a larger mouth area than the French beam trawl and has no tickler chain. With a tickler chain, the French beam trawl appears to yield more benthic catches, whilst the ORE beam trawl may be able to collect more bathypelagic species, due to its larger mouth area. In the present study, the assemblages of decapod crustaceans in Taiwan deep waters collected with the French type and the ORE type beam trawls were compared at depths of 250, 500, and 1200 meters. With multivariate analysis, the species abundance of the catches collected by both methods appeared similar, but the catches in the French beam trawl had higher taxonomic distinctness and yielded more benthic species (especially Brachyura) at depths of 250 m and 500 m when compared to the ORE beam trawl. There were no differences in abundance of pelagic species between the two trawls, suggesting that the degree of net avoidance by species in both trawls was similar. The sizes of the dominant catches were similar in both trawls, indicating that the mesh escapement was similar in both the French beam trawl and the ORE beam trawl. During operations, the French beam trawl appears to be more robust to work on rougher terrains (e.g., with lots of sunken wood and mud). In the present study, we revealed that both French beam trawl and ORE beam trawl generally show a similar performance in collecting deep-sea decapod crustaceans, except that the French beam trawl may yield a greater diversity of benthic species at the 250 and 500 m levels. Further research is needed to compare the performance of the two trawls for catching other groups of deep-sea benthic animals (e.g., molluscs and fishes), which is essential for gear consideration in quantitative community studies. Le chalut a perche francais (CP) et le ORE sont des filets communs pour la collecte des echantillons de biodiversite profonde. Le CP est equipe avec une chaine grattante et deux cotes en fer. Le ORE a une plus large ouverture que le CP et pas de chaine grattante. Avec sa chaine grattante le CP semble recolter plus de prises benthiques, tandis que le ORE semble capable de collecter plus d'especes bathypelagiques, grâce a sa plus large ouverture. Dans cette etude l'assortiment des crustaces decapodes des eaux profondes de Taiwan, collectes avec les chaluts de type francais et le ORE a ete compare pour des profondeurs de 250, 500, et 1200 metres. A partir des analyses multivariees, l'abondance des especes collectees par les deux methodes apparait similaire, mais les prises avec le CP presentent une richesse taxonomique plus elevee et comportent plus d'especes benthiques (en particulier des brachyoures) a des profondeurs de 250 et 500 m, par rapport au chalut ORE. Il n'y a pas eu de differences dans l'abondance des especes pelagiques entre les deux filets, ce qui suggere que le degre d'evitement du filet par les especes est identique pour les deux filets. La taille des prises dominantes etait semblable dans les deux chaluts, indiquant que le pourcentage d'echappement a ete similaire pour le CP et le ORE. Au cours des operations, le CP apparait plus robuste pour travailler dans des terrains difficiles (p.e. avec des bois coules ou de la vase). Dans ce travail, nous montrons que les deux chaluts presentent une performance similaire dans la collecte des crustaces decapodes benthiques, sauf que le CP produit une plus grande diversite des especes a 250 et 500 m. Des recherches plus approfondies sont necessaires pour comparer les performances des deux chaluts dans la collecte d'autres groupes d'animaux benthiques de profondeur (p.e. mollusques et poissons), ce qui est essentiel pour envisager l'utilisation des filets dans l'etude quantitative des communautes., The French beam trawl and the ORE beam trawl are common research sampling gears for deep-sea biodiversity. The French beam trawl is equipped with a tickler chain and a pair of iron sides. The ORE beam trawl has a larger mouth area than the French beam trawl and has no tickler chain. With a tickler chain, the French beam trawl appears to yield more benthic catches, whilst the ORE beam trawl may be able to collect more bathypelagic species, due to its larger mouth area. In the present study, the assemblages of decapod crustaceans in Taiwan deep waters collected with the French type and the ORE type beam trawls were compared at depths of 250, 500, and 1200 meters. With multivariate analysis, the species abundance of the catches collected by both methods appeared similar, but the catches in the French beam trawl had higher taxonomic distinctness and yielded more benthic species (especially Brachyura) at depths of 250 m and 500 m when compared to the ORE beam trawl. There were no differences in abundance of pelagic species between the two trawls, suggesting that the degree of net avoidance by species in both trawls was similar. The sizes of the dominant catches were similar in both trawls, indicating that the mesh escapement was similar in both the French beam trawl and the ORE beam trawl. During operations, the French beam trawl appears to be more robust to work on rougher terrains (e.g., with lots of sunken wood and mud). In the present study, we revealed that both French beam trawl and ORE beam trawl generally show a similar performance in collecting deep-sea decapod crustaceans, except that the French beam trawl may yield a greater diversity of benthic species at the 250 and 500 m levels. Further research is needed to compare the performance of the two trawls for catching other groups of deep-sea benthic animals (e.g., molluscs and fishes), which is essential for gear consideration in quantitative community studies. Le chalut a perche francais (CP) et le ORE sont des filets communs pour la collecte des echantillons de biodiversite profonde. Le CP est equipe avec une chaine grattante et deux cotes en fer. Le ORE a une plus large ouverture que le CP et pas de chaine grattante. Avec sa chaine grattante le CP semble recolter plus de prises benthiques, tandis que le ORE semble capable de collecter plus d'especes bathypelagiques, grâce a sa plus large ouverture. Dans cette etude l'assortiment des crustaces decapodes des eaux profondes de Taiwan, collectes avec les chaluts de type francais et le ORE a ete compare pour des profondeurs de 250, 500, et 1200 metres. A partir des analyses multivariees, l'abondance des especes collectees par les deux methodes apparait similaire, mais les prises avec le CP presentent une richesse taxonomique plus elevee et comportent plus d'especes benthiques (en particulier des brachyoures) a des profondeurs de 250 et 500 m, par rapport au chalut ORE. Il n'y a pas eu de differences dans l'abondance des especes pelagiques entre les deux filets, ce qui suggere que le degre d'evitement du filet par les especes est identique pour les deux filets. La taille des prises dominantes etait semblable dans les deux chaluts, indiquant que le pourcentage d'echappement a ete similaire pour le CP et le ORE. Au cours des operations, le CP apparait plus robuste pour travailler dans des terrains difficiles (p.e. avec des bois coules ou de la vase). Dans ce travail, nous montrons que les deux chaluts presentent une performance similaire dans la collecte des crustaces decapodes benthiques, sauf que le CP produit une plus grande diversite des especes a 250 et 500 m. Des recherches plus approfondies sont necessaires pour comparer les performances des deux chaluts dans la collecte d'autres groupes d'animaux benthiques de profondeur (p.e. mollusques et poissons), ce qui est essentiel pour envisager l'utilisation des filets dans l'etude quantitative des communautes.]

Alternative codend designs to improve size selectivity for norway lobster (nephrops norvegicus) and rose shrimp (parapenaeus longirostris) in the aegean sea

Abstract: Rose shrimp (Parapenaeus longirostris) and Norway lobster (Nephrops norvegicus) are the two main target crustaceans for the demersal trawl fleet in the international waters of the Aegean Sea. In the present study, selectivity data were obtained for these two species in commercial codends (300 MC is 40 mm polyethylene codend with 300 meshes on its circumference) and two newly designed types, known as a narrow codend (200 MC is 40 mm polyethylene codend with 200 meshes on its circumference — 33% reduced) and square mesh top panel codend (SMTPC is constructed as 150 diamond meshes on the lower and 75 square meshes on the top panel), respectively. These three types of codends were tested using the covered codend method. Trawling was carried out at depths ranging from 269 to 426 m onboard a commercial vessel in August 2004. Selection parameters were obtained by fitting a logistic equation using the maximum likelihood method. The rose shrimp, in terms of weight, was the most abundant marketable species, with catch per hour values of 19.1, 16.0, and 15.0 kg in 300 MC, 200 MC, and SMTPC, respectively. Results of the selectivity analysis indicate that the commercially used 40 mm nominal mesh size PE codend is rather unselective for these species. In general, narrow and square mesh top panel codends have relatively higher L50 values than the commercial codend. However, the differences are significant only for rose shrimp, but not for Norway lobster. It is concluded that despite the improvements in selectivity, the codend modifications 'narrow' and 'square mesh top panel' were not sufficient to release immature specimens of either species, at least not when using the 40 mm PE standard netting. La crevette rose (Parapenaeus longirostris) et la langoustine (Nephrops norvegicus) sont les deux principaux crustaces cibles de la flotille de peche au chalut demersal dans les eaux internationales de la mer Egee. Dans la presente etude, les donnees de selectivite ont ete obtenues pour ces deux especes en utilisant les culs de chalut commerciaux (300 MC est un cul de chalut de 40 mm en polyethylene avec 300 mailles sur sa circonference) et deux types nouvellement concus, a savoir un cul de chalut etroit (200 MC est un cul de chalut de 40 mm en polyethylene avec 200 mailles sur sa circonference — reduit de 33%) et un cul de chalut a panneau superieur a mailles carrees (SMTPC est construit avec 150 mailles diamant au panneau inferieur et 75 mailles carrees au panneau superieur), respectivement. Ces trois types de culs de chalut ont ete testes en utilisant la methode du cul de chalut couvert. Le chalutage a ete realise a des profondeurs allant de 269 a 426 m a bord d'un vaisseau commercial en aout 2004. Les parametres de selection ont ete obtenus en ajustant une equation logistique utilisant le maximum de ressemblance. La crevette rose etait, en termes de poids, l'espece commercialisable la plus abondante avec des valeurs de prises par heure de 19,1, 16,0 et 15,0 kg en 300 MC, 200 MC, et SMTPC, respectivement. Les resultats de l'analyse de selectivite indiquent que le cul de chalut PE de maille 40 mm, utilise commercialement est plutot non selectif pour ces especes. En general, les culs de chalut etroits et a panneau superieur a maille carree ont des valeurs de L50 relativement plus elevees que le cul de chalut commercial. Cependant, les differences sont significatives seulement pour la crevette rose, mais non pour la langoustine. Il est conclu que malgre les ameliorations quant a la selectivite, les modifications "etroit" et "panneau superieur a maille carree" n'etaient pas suffisantes pour relâcher les specimens immatures de chaque espece, au moins en utilisant le filet standard PE 40 mm.

The Potential of Ocypode Ceratophthalmus (Pallas, 1772) as a Bioindicator of Human Disturbance on Singapore Beaches

Abstract: Density and spatial distribution of the burrows of the ghost crab, Ocypode ceratophthalmus (Pallas, 1772) on the wave-washed beaches at Pulau Hantu and East Coast Park, Singapore were studied. Burrow diameter, distance of each burrow from the high water mark, mean sediment compactness, and mean particle sizes of the sediment were compared among nine sites (two island and seven mainland) with different levels of human impact. Lower burrow densities, smaller mean particle size, and more compact sediment were recorded at the more disturbed beaches. Mean burrow densities at the sites without boating activity were higher, regardless of high or low disturbance. Burrow distribution was random at all beaches although more burrows were observed near the low water level on shores with more human activity. Pulau Hantu and East Coast Park had only 0.1% and 7.3% of juvenile burrows, respectively, indicating a low recruitment rate of juvenile ghost crabs. These results provide quantitative evidence that human activities affect the abundance of O. ceratophthalmus , thereby establishing its potential as a bioindicator to assess the extent of human impact on the sandy beaches of Singapore. La densite et la distribution spatiale des terriers (galeries) du crabe, Ocypode ceratophthalmus (Pallas, 1772) sur la partie de la plage battue par les vagues a Palau Hantu et East Coast Park, Singapour ont ete etudiees. Le diametre des galeries, la distance de chaque galerie jusqu'a la limite superieure atteinte par l'eau, l'indice moyen de compactage du sediment et la taille moyenne des particules du sediment ont ete comparees entre neuf sites (deux iles et sept en terre ferme) avec differents niveaux d'impact humain. Sur les plages les plus perturbees une plus faible densite de terriers, une taille moyenne des particules plus petite et des sediments plus compacts ont ete observes. La densite moyenne des terriers sur les sites sans navigation a ete plus elevee quelque soit le niveau de perturbation. La distribution des terriers a ete aleatoire sur toutes les plages bien que plus de terriers ont ete observes pres du niveau inferieur de l'eau sur les plages avec plus d'activite humaine. Palau Hantu et East Coast Park avaient respectivement seulement 0,1% et 7,3% de terriers de juveniles, indiquant un taux de recrutement faible pour les juveniles de ce crabe. Ces resultats apportent l'evidence quantitative que les activites humaines affectent l'abondance de O. ceratophthalmus , etablissant ainsi son potentiel comme bio-indicateur pour evaluer l'etendu de l'impact humain sur les plages sableuses de Singapour.

The Gammaridea (Amphipoda) Fauna in a Mediterranean Coastal Lagoon: Considerations on Population Structure and Reproductive Biology

Abstract: [For two years, monthly samples were collected in Encanyissada coastal lagoon (Ebro Delta, N.W. Mediterranean Sea) to investigate certain aspects of the population structure and reproductive biology of the dominant species of amphipods. A total of 23 species of Gammaridea was collected, but only three species are frequent and abundant in the samples: Monocorophium insidiosum (Crawford, 1937), Gammarus aequicauda (Martynov, 1931), and Ericthonius brasiliensis (Dana, 1855). The abundance (CPUE) of all three species showed seasonal variation, with highs in autumnwinter and lows in summer, and with sex ratios favouring females. The breeding activity of M. insidiosum is high in winter and probably continuous throughout the year; brood size is related to the size of the female (range 1-36, mean value 10.2); total body length of ovigerous females ranged from 1.8 to 6.0 mm; the estimated growth rate was 14-43 μm d–1. G. aequicauda is the most regular species in the samples; its estimated growth rate was 21-99 μm d–1; breeding activity is continuous throughout the year, and brood size was also related to female size (range 1-87, mean value 23.6); total body length of ovigerous females ranged from 5.0 to 12.0 mm. The breeding activity of E. brasiliensis is very similar to that shown by M. insidiosum; brood size was also related to female size, but the mean number of eggs is lower than in M. insidiosum (mean value 7.7, range 1-24); total body length of ovigerous females ranged from 1.7 to 5.6 mm; its estimated growth rate was 20-56 μm d–1. Durante dos anos, se ha realizado un muestreo mensual en la laguna costera de la Encanyissada (Delta del Ebro, NO Mediterraneo) con la finalidad de investigar ciertos aspectos de la estructura poblacional y la biologia reproductiva de las especies dominantes de anfipodos. Un total de 23 especies de Gammaridea fueron capturadas, pero solo tres fueron frecuentes y abundantes en las muestras: Monocorophium insidiosum (Crawford, 1937), Gammarus aequicauda (Martynov, 1931) y Ericthonius brasiliensis (Dana, 1855). La abundancia (CPUE) de las tres especies muestra variacion estacional, siendo maxima en otono-invierno y minima en verano. En las tres especies, las hembras son mas abundantes que los machos. La actividad reproductora de M. insidiosum es alta en invierno y probablemente continua durante todo el ano; el tamano de la puesta esta correlacionado con el tamano de la hembra (rango 1-36; valor medio 10,2); la longitud total de las hembras ovigeras es de 1,8 a 6,0 mm; la tasa de crecimiento estimada para esta especie es de 14-43 μm d–1. G. aequicauda es la especie mas regular en las muestras; la tasa de crecimiento para esta especie es 21-99 μm d–1; la actividad reproductora es continua durante todo el ano, y el tamano de las puesta esta relacionada con la talla de la hembra (rango 1-87, valor medio 23,6); la longitud de las hembras ovigeras es de 5,0 a 12,0 mm. La actividad reproductora de E. brasiliensis es similar a la de M. insidiosum; el tamano de las puesta tambien esta relacionada con el tamano de la hembra, pero el numero medio de huevos por cada hembra es menor que en M. insidiosum (rango 1-24, valor medio 7,7); la longitud de las hembras ovigeras es 1,7-5,6 mm; la tasa de crecimiento para esta especie es de 20-56 μm d–1., For two years, monthly samples were collected in Encanyissada coastal lagoon (Ebro Delta, N.W. Mediterranean Sea) to investigate certain aspects of the population structure and reproductive biology of the dominant species of amphipods. A total of 23 species of Gammaridea was collected, but only three species are frequent and abundant in the samples: Monocorophium insidiosum (Crawford, 1937), Gammarus aequicauda (Martynov, 1931), and Ericthonius brasiliensis (Dana, 1855). The abundance (CPUE) of all three species showed seasonal variation, with highs in autumnwinter and lows in summer, and with sex ratios favouring females. The breeding activity of M. insidiosum is high in winter and probably continuous throughout the year; brood size is related to the size of the female (range 1-36, mean value 10.2); total body length of ovigerous females ranged from 1.8 to 6.0 mm; the estimated growth rate was 14-43 μm d–1. G. aequicauda is the most regular species in the samples; its estimated growth rate was 21-99 μm d–1; breeding activity is continuous throughout the year, and brood size was also related to female size (range 1-87, mean value 23.6); total body length of ovigerous females ranged from 5.0 to 12.0 mm. The breeding activity of E. brasiliensis is very similar to that shown by M. insidiosum; brood size was also related to female size, but the mean number of eggs is lower than in M. insidiosum (mean value 7.7, range 1-24); total body length of ovigerous females ranged from 1.7 to 5.6 mm; its estimated growth rate was 20-56 μm d–1. Durante dos anos, se ha realizado un muestreo mensual en la laguna costera de la Encanyissada (Delta del Ebro, NO Mediterraneo) con la finalidad de investigar ciertos aspectos de la estructura poblacional y la biologia reproductiva de las especies dominantes de anfipodos. Un total de 23 especies de Gammaridea fueron capturadas, pero solo tres fueron frecuentes y abundantes en las muestras: Monocorophium insidiosum (Crawford, 1937), Gammarus aequicauda (Martynov, 1931) y Ericthonius brasiliensis (Dana, 1855). La abundancia (CPUE) de las tres especies muestra variacion estacional, siendo maxima en otono-invierno y minima en verano. En las tres especies, las hembras son mas abundantes que los machos. La actividad reproductora de M. insidiosum es alta en invierno y probablemente continua durante todo el ano; el tamano de la puesta esta correlacionado con el tamano de la hembra (rango 1-36; valor medio 10,2); la longitud total de las hembras ovigeras es de 1,8 a 6,0 mm; la tasa de crecimiento estimada para esta especie es de 14-43 μm d–1. G. aequicauda es la especie mas regular en las muestras; la tasa de crecimiento para esta especie es 21-99 μm d–1; la actividad reproductora es continua durante todo el ano, y el tamano de las puesta esta relacionada con la talla de la hembra (rango 1-87, valor medio 23,6); la longitud de las hembras ovigeras es de 5,0 a 12,0 mm. La actividad reproductora de E. brasiliensis es similar a la de M. insidiosum; el tamano de las puesta tambien esta relacionada con el tamano de la hembra, pero el numero medio de huevos por cada hembra es menor que en M. insidiosum (rango 1-24, valor medio 7,7); la longitud de las hembras ovigeras es 1,7-5,6 mm; la tasa de crecimiento para esta especie es de 20-56 μm d–1.]

A New Species of the Alpheid Shrimp Genus Salmoneus (Decapoda, Caridea) from the Ryukyu Islands, Japan, Associated with a Callianassid Ghost Shrimp (Decapoda, Thalassinidea)

Abstract: [A new species of the alpheid shrimp genus Salmoneus Holthuis, 1955, S. brucei sp. nov., is described and illustrated from Iriomote Island, southern Ryukyu Islands, Japan. The type series was obtained by yabby pump from burrows of the callianassid ghost shrimp, Lepidophthalmus tridentatus (Von Martens, 1868). The new species is unique within the genus in the lack of orbital teeth of the carapace, but the presence of numerous setae on the fingers of the chelipeds and the enlarged minor cheliped link it to S. seticheles Anker, 2003, known from the Northern Territory, Australia. Eine neue Art der alpheiden Gattung Salmoneus Holthuis, 1955, S. brucei sp. nov, wird von der Insel Iriomote, sudliche Ryukyu Inseln, Japan, beschrieben und illustriert. Die Typenserie wurde mit einer Saugpumpe aus Bauten des Maulwurfskrebses Lepidophthalmus tridentatus (Von Martens, 1868) erbeutet. Die neue Art ist einzigartig innerhalb der Gattung wegen des Fehlens orbitaler Zahne am Carapax. Das Vorhandensein zahlreicher Borsten auf den Fingern beider Scheren und die vergroserte kleine Schere stellen sie in die Nahe von S. seticheles Anker, 2003 aus dem Northern Territory Australiens., A new species of the alpheid shrimp genus Salmoneus Holthuis, 1955, S. brucei sp. nov., is described and illustrated from Iriomote Island, southern Ryukyu Islands, Japan. The type series was obtained by yabby pump from burrows of the callianassid ghost shrimp, Lepidophthalmus tridentatus (Von Martens, 1868). The new species is unique within the genus in the lack of orbital teeth of the carapace, but the presence of numerous setae on the fingers of the chelipeds and the enlarged minor cheliped link it to S. seticheles Anker, 2003, known from the Northern Territory, Australia. Eine neue Art der alpheiden Gattung Salmoneus Holthuis, 1955, S. brucei sp. nov, wird von der Insel Iriomote, sudliche Ryukyu Inseln, Japan, beschrieben und illustriert. Die Typenserie wurde mit einer Saugpumpe aus Bauten des Maulwurfskrebses Lepidophthalmus tridentatus (Von Martens, 1868) erbeutet. Die neue Art ist einzigartig innerhalb der Gattung wegen des Fehlens orbitaler Zahne am Carapax. Das Vorhandensein zahlreicher Borsten auf den Fingern beider Scheren und die vergroserte kleine Schere stellen sie in die Nahe von S. seticheles Anker, 2003 aus dem Northern Territory Australiens.]

Reproductive efficiency of the narrow-clawed crayfish, Astacus leptodactylus, in several populations in Turkey

Abstract: Studies were carried out to evaluate the reproductive efficiency of the narrow-clawed crayfish, Astacus leptodactylus Eschscholtz, 1823, in three different populations in the lakes Apolyont, Iznik, and Manyas in Turkey. Crayfish were sampled monthly using fyke-nets of 34 mm mesh size from April 2002 until March 2003. The average number of pleopodal eggs (with their range), per female, was 200 ± 12 (8-556) in Lake Apolyont, 202 ± 13 (6-350) in Lake Iznik, and 257 ± 13 (18-465) in Lake Manyas. The average number of ovarian eggs (with their range), per female, was 348 ± 20 (126-630) in Lake Apolyont, 305 ± 11 (162-465) in Lake Iznik, and 400 ± 18 (205-776) in Lake Manyas. The average egg diameter and ranges were 2.23 ± 0.004 (1.80-2.98) mm in Lake Apolyont, 2.53 ± 0.003 (2.06-2.92) mm in Lake Iznik, and 2.65 ± 0.027 (1.98-3.04) mm in Lake Manyas. Neither egg diameter nor egg weight increased with body size, but the variability of egg size and weight was high. No relationship was found between egg size and female crayfish size for any of the lakes. Mean size at maturity of female A. leptodactylus varied among the lakes. Females in Apolyont populations reached sexual maturity at a size of 64.3 mm TL, but spawning occurred only when females attained 82-128 mm TL, indicating that the mean minimum reproductive size was 82 mm TL in Lake Apolyont. Average female size was 88.7 mm (±SD 0.6; max. 142 mm; min. 48 mm; n = 154). In Iznik Lake, size at maturity of females was 78 mm TL, while spawning size was 83142 mm TL; average female size was 90.6 mm (±SD 0.5; max. 139 mm; min. 66 mm; n = 99). Finally, female size at maturity was 72.6 mm TL, and spawning size was 80-130 mm TL in Manyas Lake; average female size was 89.0 mm (±SD 1.1; max. 141 mm; min. 29 mm; n = 122). The total observed sex ratio (male/female) was found to be 1.00/0.53 in all three lakes together. Mature A. leptodactylus reproduce only once a year under natural conditions. No evidence was found in this study to suggest the occurrence of multiple spawnings.