Showing papers on "Digenea published in 2007"
TL;DR: Three new species of Cryptogonimidae belonging to two new genera are described from the large piscivorous reef fish Lutjanus bohar recovered from Heron and Lizard Islands off the Great Barrier Reef and Rasdhoo Atoll, Maldives, to explore the geographic distribution and integrity of the putative species recovered from these widespread localities.
Abstract: We describe three new species of Cryptogonimidae belonging to two new genera, Caulanus gen. nov. and Latuterus gen. nov., from the large piscivorous reef fish Lutjanus bohar Forsskal, 1775, recovered from Heron and Lizard Islands off the Great Barrier Reef and Rasdhoo Atoll, Maldives. To support our morphologically based taxonomic approach, three nuclear ribosomal DNA regions (28S, ITS1 and ITS2) were sequenced and analysed to explore the geographic distribution and integrity of the putative species recovered from these widespread localities. Sequencing of the rDNA regions included multiple replicates and revealed three distinct genotypes. Two of the observed genotypes were associated with phenotypically similar specimens of Latuterus, but were each restricted to a single locality, Lizard Island, GBR or Rasdhoo Atoll, Maldives. A posteriori analysis of the associated morphotypes revealed distinct morphological differences and these consistent differences, in combination with the consistent genetic differences led to the recognition of two distinct species in the system. Caulanus is distinguished by having oral spines, caeca which open via ani at the posterior end of the body, tandem testes and uterus that extends from the posterior end of the body to the pharynx. Latuterus is distinguished by lacking oral spines, having multiple/follicular testes, a uterus that is extensive in both fore-and hindbody and vitelline follicles which are confined to the region from the pharynx to oral sucker. Caulanus thomasi sp. nov. had identical sequences for all of the rDNA regions examined from specimens recovered from all three localities, indicating that this species has a wide Indo-Pacific distribution. The species reported here are evidently restricted to Lutjanus bohar because they were never found in large numbers of other lutjanid species sampled at the same localities.
37 citations
Journal Article•
TL;DR: To determine the biodiversity of digenean larvae in the snail populations from various water bodies, snails under study were collected from 29 reservoirs situated in northern and central part of Poland during the period 1999-2005.
Abstract: BACKGROUND The aim of this work was to determine the biodiversity of digenean larvae in the snail populations from various water bodies. MATERIAL AND METHODS Snails under study were collected from 29 reservoirs situated in northern and central part of Poland. During the period 1999-2005 10.581 snails from 6 species (among which two species dominated: Lymnaea stagnalis--9.469, and Planorbarius corneus--737 specimens) were examined for shedding cercariae. The total number of 4.404 molluscs was parasitized by 25 species of Digenea. The dominant species found were: Diplostomum pseudospathaceum (Diplostomidae), Echinoparyphium aconiatum (Echinostomatidae) Plagiorchis elegans and Opisthioglyphe ranae (Plagiorhiidae) in Lymnaeidae, while Rubenstrema exasperatum/Neoglyphe locellus (Omphalometridae) and Tylodelphys excavata (Diplostomatidae) in Planorbidae. The adults of the most of Digenea species found in snails were reported from birds.
27 citations
TL;DR: Despite their superficial morphological and host preference similarities, species of Beluesca and Chelediadema were genetically distant from each other, and interspecific and intergeneric variation among the species described here is similar to that reported for other cryptogonimids.
Abstract: A survey of the parasites of Indo-West Pacific Haemulidae revealed the presence of three new cryptogonimid (Digenea: Cryptogonimidae) species warranting two new genera, Beluesca littlewoodi n. gen., n. sp. and B. longicolla n. sp. from the intestine and pyloric caeca of Plectorhinchus gibbosus and Chelediadema marjoriae n. gen., n. sp. from the intestine and pyloric caeca of Diagramma labiosum, P. albovittatus and P. gibbosus from Heron and Lizard Islands off the Great Barrier Reef, Australia. Beluesca n. gen. is distinguished from all other cryptogonimid genera by the combination of an elongate body, funnel-shaped oral sucker, relatively small number of large oral spines, highly lobed ovary, opposite to slightly oblique testes, uterine loops that are restricted to the hindbody and extend well posterior to the testes and vitelline follicles that may extend from the ovary into the forebody, but do not extend anterior to the intestinal bifurcation. Pseudallacanthochasmus plectorhynchi Mamaev, 1970 is transferred to Beluesca as B. plectorhyncha (Mamaev, 1970) n. comb. based on morphological and ecological (host preference) characteristics. Chelediadema n. gen. is distinguished from all other cryptogonimid genera by the combination of a lanceolate body, relatively small number of large oral spines, prepharynx that is much longer than the oesophagus, tandem testes, uterine loops that are extensive in the hindbody and extend well posterior to the testes and vitelline follicles that extend from the ovary to the pharynx. Morphological analysis of the three species described here was augmented with DNA sequence analyses utilizing data from the large subunit (LSU) and the internal transcribed spacers (ITS) 1 and 2, and 5.8S nuclear ribosomal DNA. Sequence data from the LSU and ITS (encompassing the ITS1, 5.8S and ITS2) of the taxa examined here were aligned with those reported for other cryptogonimids, Caulanus thomasi, Latuterus tkachi, Neometadena ovata, four representative species of Retrovarium and an undescribed species of Siphoderina, for comparative purposes and to explore levels of interspecific and intergeneric variation among these taxa. Minimum evolution analysis was conducted on a combined (LSU and ITS) dataset to explore relationships among these genera. Despite their superficial morphological and host preference similarities, species of Beluesca and Chelediadema were genetically distant from each other. Interspecific and intergeneric variation among the species described here is similar to that reported for other cryptogonimids.
23 citations
TL;DR: Aptorchis megacetabulus n.
Abstract: Aptorchis megacetabulus n. sp. is described from the intestine of the northern long-necked turtle, Chelodina rugosa (Pleurodira: Chelidae), in Northern Territory, Australia. This is the first helminth species reported from C. rugosa. This plagiorchioidean digenean differs from the 3 previously known species of Aptorchis in the relative size of the ventral sucker, overall body proportions, nature of the cirrus sac, and egg size. Comparison of approximately 2,700 bases of ribosomal DNA obtained from all known Aptorchis species strongly supports the status of Aptorchis megacetabulus n. sp. as a new species.
23 citations
01 Jan 2007
TL;DR: Aptorchis megacetabulus n. sp. as discussed by the authors was reported from the intestine of the northern longnecked turtle, Chelodina rugosa (Pleurodira: Chelidae), in Northern Territory, Australia.
Abstract: Aptorchis megacetabulus n. sp. is described from the intestine of the northern long-necked turtle, Chelodina rugosa (Pleurodira: Chelidae), in Northern Territory, Australia. This is the first helminth species reported from C. rugosa. This plagior- chioidean digenean differs from the 3 previously known species of Aptorchis in the relative size of the ventral sucker, overall body proportions, nature of the cirrus sac, and egg size. Comparison of approximately 2,700 bases of ribosomal DNA obtained from all known Aptorchis species strongly supports the status of Aptorchis megacetabulus n. sp. as a new species.
16 citations
TL;DR: The morphology of two species of bucephalids (Bucephalidae; Digenea; Trematoda), which since 1999 has caused a fish disease at the Uji River, Kyoto Prefecture, Japan, is described.
14 citations
TL;DR: Larval stages, including germinal sacs, found in mytilids from the Patagonian coast were identified as P. australis and it is proposed that the least unambiguous characters that can be used to distinguish gymnophallid genera include the position of the ovary, the presence of a ventral pit and a pars prostatica, and caecal diverticula.
Abstract: Parvatrema australis (Szidat, 1962) Szidat, 1965 was described based on larval stages found in specimens of the mussel Mytilus edulis from the Buenos Aires Province, Argentina. Although Szidat later examined hundreds of mussels, this parasite has never been found again until now. In the present study, larval stages, including germinal sacs, found in mytilids from the Patagonian coast were identified as P. australis. Metacercariae were incubated in vitro at 39°C in physiological solution for 18–20 hours, by which time 80% of the specimens had eggs. P. australis is redescribed, on the basis of infective metacercariae and adults obtained in the laboratory, and is reassigned to Gymnophallus Odhner, 1900, the genus in which it was originally described. The generic diagnosis of Gymnophallus is here amended to include as diagnostic characters the presence or absence of the lateral lips, the form and position of the vitellarium (compact or follicular) and the presence of a pars prostatica (i.e. prostatic cells open into proximal part of the ejaculatory duct). The validity of some characters (i.e. the presence of lateral lips of the oral sucker, the form of the vitellarium and excretory vesicle, the extent of the uterus) as diagnostic at the generic level within the family Gymnophallidae is discussed. It is proposed that the least unambiguous characters that can be used to distinguish gymnophallid genera include the position of the ovary, the presence of a ventral pit and a pars prostatica, and caecal diverticula.
12 citations
Journal Article•
TL;DR: Larval cestodes were the dominant parasites, whereas acanthocephalans were relatively rare, and five species and larval forms were recorded also in fish caught in the Davis Sea.
Abstract: Trematomus newnesi (Nototheniidae), a bentho−pelagic fish, caught off Adelie Land (eastern Antarctic) was examined for the presence of internal parasitic worms. These fishes were infected with 11 species and larval forms of parasites: Digenea (Macvicaria pennelli, Neolebouria terranovaensis, Genolinea bowersi, and Elytrophalloides oatesi), larval Cestoda (two forms of tetraphyllidean metacestodes, bilocular form and trilocular form, and diphyllobothriid plerocercoids), Acanthocephala (Metacanthocephalus camp− belli, M. johnstoni) and larval Nematoda (Contracaecum osculatum, C. radiatum). Larval cestodes were the dominant parasites, whereas acanthocephalans were relatively rare. Five species and larval forms were recorded also in fish caught in the Davis Sea. A check list of parasites of T. newnesi recorded in the eastern− and western Antarctic comprises 21 species and larval forms. Probably, T. newnesi plays an important role in life cycles of parasitic worms in the Antarctic.
12 citations
TL;DR: It has been first proven that the shore crab M. dilatatus is a second intermediate host for G. squatarolae in the Republic of Korea.
Abstract: Metacercariae of Gynaecotyla squatarolae (Digenea: Microphallidae) were discovered from the shore crab, Macrophthalmus dilatatus, purchased at a market in a coastal town of Taean-Eup, Chungcheongnam-do, Republic of Korea. Their adult flukes were confirmed by experimental infection of rats. The metacercariae of G. squatarolae were elliptical (391.1 x 362.5 micrometer), and the excysted metacercariae had progenetic genital organs, including the ovary and testes. To obtain adult flukes, 6 Sprague-Dawley rats were fed 500 metacercariae each, and killed at days 2, 4, and 6 post-infection. The adult flukes were identified as G. squatarolae (Yamaguti, 1934) Yamaguti, 1939, based on morphological characters, including 2 ventral suckers (1 large and 1 small), a large genital atrium equipped with the cirrus and the metraterm, separated male and female genital pores, a transversely long cirrus pouch, and extensive vitelline follicles. In the present study, it has been first proven that the shore crab M. dilatatus is a second intermediate host for G. squatarolae in the Republic of Korea.
11 citations
TL;DR: The morphology of the vitellarium and the genital pore with an anterior arch of 16-17 sensory papillae are unique features and are proposed as a new species, Parvatrema chaii n.
Abstract: Parvatrema chaii n. sp. (Digenea: Gymnophallidae) is described using the worms recovered from experimentally infected mice in Korea. The metacercariae were collected from surf-clams, Mactra veneriformis, from a tidal flat in Sochon-gun, Chungchongnam-do. The metacercariae were elliptical (0.262 × 0.132 mm), and the genital pore had an anterior arch of 16-17 sensory papillae in scanning electron microscopic view. Adult worms were ovoid to foliate (0.275-0.303 by 0.140-0.150 mm), and their characteristic features included the presence of lateral lips, short esophagus, genital pore located some distance anterior to the ventral sucker, club-shaped seminal vesicle, a compact to slightly lobed vitellarium, elliptical eggs (0.018-0.020 by 0.010-0.013 mm), and absence of the ventral pit. This gymnophallid is classified as a member of the genus Parvatrema because of the location of the wide genital pore some distance from the ventral sucker, and the absence of the ventral pit. It differs from previously reported Parvatrema species, including the type species, P. borinquenae. In particular, the morphologies of the vitellarium and the genital pore with an anterior arch of 16-17 sensory papillae are unique features. Therefore, we propose it as a new species, Parvatrema chaii n. sp. (Digenea: Gymnophallidae).
9 citations
TL;DR: A new species of Haplometroides is described from a specimen of Phalotris nasutus (Gomes, 1915) (Serpentes, Colubridae) obtained in the municipality of Corumbá, Mato Grosso do Sul State, Brazil.
Abstract: A new species of Haplometroides (Digenea, Plagiorchiidae) is described from a specimen of Phalotris nasutus (Gomes, 1915) (Serpentes, Colubridae). The host snake was obtained in the municipality of Corumba, Mato Grosso do Sul State, Brazil. Trematodes were recovered from esophagus, stomach, and small intestine of the host. The main characteristic of the new species is the vitellaria, which is intercecal, cecal, and extracecal in the preacetabular region. A key for identification of the species in Haplometroides is proposed.
TL;DR: This new species resembles the type species Meiogymnophallus affinis, but differs in having compact, elliptical, and 4–5-lobed vitellaria, and an excretory vesicle with bicornuated anterior arms reaching to the oral sucker.
Abstract: Meiogymnophallus sinonovaculae n. sp. (Digenea: Gymnophallidae) is described from metacercariae found in the razor clam, Sinonovacula constricta, in the Republic of Korea, and adults recovered from the small intestine of experimentally infected mice. The worms are characterized by paired clusters of vitelline follicles, a well-developed pars prostatica with abundant prostate cells, a voluminous undivided seminal vesicle (in adults and metacercariae), and large, grouped, domelike sensory papillae on the ventral surface anterior to the ventral sucker (in metacercariae). This new species resembles the type species Meiogymnophallus affinis, but differs in having compact, elliptical, and 4–5-lobed vitellaria, and an excretory vesicle with bicornuated anterior arms reaching to the oral sucker. This is the second documentation of the presence of a species of Meiogymnophallus in the Republic of Korea.
Journal Article•
TL;DR: A new species of trematode, Pleurogonius tortugueroi n.
Abstract: A new species of trematode, Pleurogonius tortugueroi n. sp. (Digenea: Pronocephalidae) is described from the lower intestine of green sea turtles (Chelonia mydas) from Tortuguero National Park, Costa Rica. The new species differs from all other species of Pleurogonius by having a short oesophagus and oval testes close to lateral posterior limit of the body. It differs from all other species, except P. malaclemys Hunter 1961, by having an ovary between the testes; moreover the latter species is a parasite of freshwater turtles. All others members of the genus have a long oesophagus, testes placed to some distance from the posterior end, and the ovary is pretesticular. The new species appears most closely related to P. linearis Looss, 1901 but differs from it by having a different body shape, lappets of the head collar close at the cecal bifurcation level, a longer vitellarian field, different testis shape and position, ovary intertesticular, and different egg size.
TL;DR: The new species differs from Macrourimegatrema brayi Blend, Dronen & Armstrong, 2004, in the distribution of the vitelline follicles and gonads, a larger body size, and the presence of highly-folded caeca with numerous outpocketings or pouches.
Abstract: Macrourimegatrema gadoma n. sp. (Digenea: Opecoelidae: Plagioporinae) is described from the pyloric caeca and intestine of the doublethread grenadier Gadomus arcuatus (Goode & Bean) (Macrouridae) collected from the northeastern Gulf of Mexico and off Venezuela. The new species differs from Macrourimegatrema brayi Blend, Dronen & Armstrong, 2004, the type and only species in the genus, in the distribution of the vitelline follicles and gonads, a larger body size, and the presence of highly-folded caeca with numerous outpocketings or pouches. It is suggested that species of Macrourimegatrema Blend, Dronen & Armstrong, 2004 probably infect their piscine hosts through the ingestion of a benthopelagic crustacean.
01 Jan 2007
TL;DR: The presence of mature parasites throughout the year in crabs of both sexes and all size classes, demonstrated by in vitro metacercarial excystment and liberation of ovigerous flukes, suggests continuous transmission from crab to bird is possible.
Abstract: The seasonal dynamics of larval stages of the microphallid trematode Maritrema eroliae Yamaguti, 1939 in intermediate hosts, the prosobranch snail Clypeomorus bifasciata(Sowerby, 1855)and the brachyuran crab Nanosesarma minutum(de Man, 1887), in Kuwait Bay was examined. Over a one-year period,1 600 snails and 415 crabs were collected and examined for larval trematodes, 11.8% of snails were infected with one of 8 species dominated by M.eroliae(9.9%), and 80% of crabs harbored M.eroliae metacercariae. Although infections persisted in both host species throughout the year, significant summer peaks were recorded in parasite prevalence and cercarial emergence(i.e., indicating mature infection)in snails. Cercarial emergence from snails was significantly seasonal, a minimum temperature of 20℃ in the Bay must be exceeded to activate emergence. Overall prevalence of infections decreased in larger(older)snails, suggesting parasite interference with host survival and consequently with host population structure. There was a significant correlation between metacercarial abundance and crab size; larger crabs harbored more metacercariae suggesting host tolerance to parasite accumulation. No correlations were detected between metacercarial prevalence and crab size or sex. The presence of mature parasites throughout the year in crabs of both sexes and all size classes, demonstrated by in vitro metacercarial excystment and liberation of ovigerous flukes, suggests continuous transmission from crab to bird is possible. In general, the transmission dynamics of M.eroliae in the Bay are coordinated between the two invertebrate host species and appears to be controlled by a set of temperature-dependent activities influencing the availability of susceptible host populations and infective larval stages, cercariae and metacercariae[Acta Zoologica Sinica 53(3):463-469,2007].
TL;DR: In this paper, the prevalence and intensity of parasites in young-of-the-year herring were found and discussed. But the authors focused on the prevalence of the parasites and not the intensity of the infections.
Abstract: The parasite fauna of young-of-the-year herring Clupea harengus L., off Gullmarsfjord and Brofjorden, west coast of Sweden, was studied between May and October for 4 years, from 1994 to 1997. Fifteen species of parasites were found: two Protozoa – Trichodina sp. and Ceratomyxa auerbachi; one species of uncertain affinity – Ichthyophonus hoferi; two Monogenea – Gyrodactylus harengi and Pseudanthocotyloides heterocotyle; five Digenea – Cryptocotyle lingua metacercariae, Cercaria pythionike metacercariae, Hemiurus luehei, Lecithaster confusus and Pseudobacciger harengulae; three Cestoda plerocercoids – Bothriocephalus sp., an acrobothriid and a tetraphyllid; one Nematoda – Hysterothylacium aduncum larva; and one Copepoda – Caligus elongatus. The number of species found in this study represents more than one-sixth of all parasites reported in herring worldwide and all parasites were acquired locally. The parasite fauna of herring from the west coast of Sweden is compared with that of herring from the Baltic Sea and other areas of the north-east Atlantic. The prevalence and intensity of parasites are presented and discussed. Morphological descriptions are based on both light and scanning electron microscopy and new features are described. Possible applications of this new information about the parasite fauna, in different areas of fisheries and fish biology studies, are discussed.
TL;DR: Experimental evidence and analysis of metacercarial group composition in naturally infected molluscs indicate that some cercariae leave their mollUScan hosts and penetrate other specimens of Falsicingula in which they develop into new cerbariae-producing PM.
Abstract: Previously unknown gymnophallid parthenogenetic metacercariae (PM), referred to as Cercaria falsicingulae I larva nov., were found in the extrapallial cavities of the snails Falsicingula mundana (Yokoyama) and F. athera (Bartsch) on coasts of Sakhalin and the Kuril Islands. Unlike all other known PM, rather than producing metacercariae infective to the definitive host, their furcocercariae emerge into the environment. The developing cercariae and metacercariae of C. falsicingulae I are described and compared with other gymnophallid larvae from littoral molluscs in the region. Experimental evidence and analysis of metacercarial group composition in naturally infected molluscs indicate that some cercariae leave their molluscan hosts and penetrate other specimens of Falsicingula in which they develop into new cercariae-producing PM. Metacercariae with developing hermaphroditic reproductive organs were never observed in naturally infected molluscs. A probable life-cycle for C. falsicingulae I is presented in which cercarial/metacercarial production is switched seasonally in order to enable the infection of the definitive hosts by PM. Importantly, the ‘cercaria – PM – cercaria’ component of the life-cycle appears to be somewhat autonomous.
Journal Article•
TL;DR: The author presents an overview of isolated trematodes along their morphological description, isolated from the hosts that are for the first time reported in the North Adriatic Sea, as an object of the present paper.
Abstract: The author presents an overview of isolated trematodes along their morphological description, isolated from the hosts that are for the first time reported in the North Adriatic Sea. The endohelminth parasites invasion of Northern Adriatic fish was studied during a 10-year research program. A total of 63 marine fish species of pelagic and bentic fish of the classes Chondrichthyes and Osteichthyes were analysed. Twenty-two fish species were found to host Digenean trematodes (33.33% prevalence), and 12 new host fish were reported for this class. During this endohelminths parasitofauna research work 63 species of sea-fish from Northern Adriatic (total of 2659 fish) were examined and 25.16% found invaded by some of endohelminths. The presence of 22 different species of flukes (Trematoda, Digenea) was found. Flukes were present in 33.33% of invaded fish. Furthermore 12 new fish hosts for Trematodes were found and this is the object of the present paper. The names of the investigated species of Trematodes together with those of their new hosts are listed in Table 1. The data referring to each parasite are given in the specific part of this study.