FROM the time of its appearance half a century ago, Jordan and Everyman's "Fishes of North and Middle America"has until to-day remained the only comprehensive descriptive account of the fishes of the western Atlantic Ocean. Much new knowledge has become available during this long period, and the time is now ripe for a new and up-to-date publication covering approximately the same field. The appearance of Volume 1 of "Fishes of the Western North Atlantic" is therefore most welcome and will supply a much-felt need. This volume, the first of a projected series, brings to fruition the. initial part of a plan conceived in New Haven a considerable time ago. With the establishment of the Sears Foundation for Marine Research at Yale University in, 1937, funds became available for publication on auite an ambitious scale, and a group of expert ichthyologists met to discuss the preparation of a work such as is now appearing. Fishes of the Western North Atlantic Part 1: Lancelets, by Henry B. Bigelow Isabel Perez Paufante; Cyclostomes, by Henry B. Bigelow and William C. Schroeder; Sharks, by Henry B. Bigelow and William C. Schroeder. (Sears Foundation for Marine Research, Memoir No. 1.) Pp. xvii+576. (New Haven, Conn.: Yale University, 1948.) 10 dollars.

Fishes of the Western North Atlantic

Anthropogenic Marine Debris (AMD) in the SE Pacific has primarily local origins from land-based sources, including cities (coastal and inland), beach-goers, aquaculture, and fisheries. The low frequency of AMD colonized by oceanic biota (bryozoans, lepadid barnacles) suggests that most litter items from coastal waters of the Humboldt Current System (HCS) are pulled offshore into the South Pacific Subtropical Gyre (SPSG). The highest densities of floating micro- and macroplastics are reported from the SPSG. An extensive survey of photographic records, unpublished data, conference proceedings, and published studies revealed interactions with plastics for 97 species in the SE Pacific, including 20 species of fish, 5 sea turtles, 53 seabirds, and 19 marine mammals. Sea turtles are most affected by interactions with plastics, underlined by the fact that 4 of the 5 species suffer both from entanglement and ingestion. Reports gathered in this review suggest that interactions along the continental coast are mostly via entanglement. High frequencies of microplastic ingestion have been reported from planktivorous fish and seabirds inhabiting the oceanic waters and islands exposed to high densities of microplastics concentrated by oceanic currents in the SPSG. Our review also suggests that some species from the highly productive HCS face the risk of negative interactions with AMD, because food and plastic litter are concentrated in coastal front systems. In order to improve the conservation of marine vertebrates, especially of sea turtles, urgent measures of plastic reduction are needed.

/pdf/impacts-of-marine-plastic-pollution-from-continental-coasts-h7c8y2krq6.pdf

Impacts of marine plastic pollution from continental coasts to subtropical gyres-fish, seabirds, and other vertebrates in the SE Pacific

Cold-water coral reef habitats benefit recreationally valuable sharks

Ebert, D. A., Compagno, L. J. V., and Cowley, P. D. 2008. Aspects of the reproductive biology of skates (Chondrichthyes: Rajiformes: Rajoidei) from southern Africa. - ICES Journal of Marine Science, 65: 81-102.New information is presented on the reproductive biology of 22 southern African skate species. Sex ratios for most species were relatively even. Sexual dimorphic differences in disc shape were evident in all species, but the total length (L T ) to disc width (D) relationship was significantly different in only three species, and the L T to weight (W) relationship significant in just five species. Sexual dimorphism relative to maximum total length (L Tmax ) was absent in all but the two largest species. Males and females of the same species grow to a similar L Tmax except those whose L Tmax is >1.5 m L T . Size at first and 50% (L T50 ) sexual maturity was approximately the same for both sexes in all but the two largest species. First maturity occurred at >60% of L Tmax for all species for which sufficient data were available, and most (n = 18) matured at >75% L Tmax . The large size at maturity relative to L Tmax suggests that growth slows or is partially suspended following sexual maturity. The egg cases of 15 species are described, and a key to their identification is presented. Egg cases in utero were observed throughout the year suggesting that most species reproduce year-round.

Aspects of the reproductive biology of skates (Chondrichthyes: Rajiformes: Rajoidei) from southern Africa

The age and growth parameters of Dipturus chilensis were estimated by counting growth rings from thin sections of vertebral centra from 400 fish (246 females and 154 males), ranging from 23 to 124 cm total length (L T ), and backcalculating fish lengths at previous ages. Marginal increment analysis lent support to the hypothesis of annual deposition of band-pairs, which formed during the winter months. The oldest female D. chilensis aged in this study was 21 years and 117 cm L T , whereas the oldest male was 18 years and 93 cm L T . A 4.7% index of average per cent error (T APE ) suggested that this is a precise method for calculating the age of D. chilensis. Observed L T were lower than backcalculated L T , which implies the influence of Lee's phenomenon. The von Bertalanffy growth equations, based on mean length-at-age data, were estimated as L t = 128.3(1 -e -0·112(t+0·514) ) for females and L t = 107·8(1 - e -0·134(t +0·862) ) for males where t is age (years). Growth was significantly different between sexes: females reached a larger adult size. Ages and lengths at 50% maturity were estimated at 14 years of age and 106 cm L T for females and 11 years of age and 86 cm L T for males. At c. 14 years, there was a decline in growth rates in females. The factor most likely responsible for this was sexual maturity, which caused a discontinuity in growth of female fish. These results show that this species is slow-growing, long-lived, relatively large and of delayed maturity, characteristics that make it vulnerable to exploitation.

Age, growth, and sexual maturity of the yellownose skate Dipturus chilensis in the south‐eastern Pacific

A total of 459 (245 females, 214 males) Atlantoraja cyclophora was captured by bottom trawl off the coast of Rio Grande do Sul between 30°40′S and 34°30′S during surveys conducted in winter 2001 and summer/autumn 2002 at depths of 100-300 m. Total length at maturity was 52.8 cm for females and 48.5 cm for males. Symmetry and functional parity of the gonads were observed in both sexes, but there was no significant temporal variation in either sex for any of the reproductive parameters studied. Ovulation and egg-deposition were similarly intensive in both seasons. In adult females, there was an ovarian resting period at an individual level, though it was not synchronized at a population level. Distribution of egg-bearing females was not related to depth or species' range.

/pdf/reproductive-biology-of-atlantoraja-cyclophora-regan-1903-wjwgnthcvv.pdf

Reproductive biology of Atlantoraja cyclophora (Regan 1903) (Elasmobranchii: Rajidae) off southern Brazil

Specimens of Rioraja agassizi were collected at Guaruja pier, Sao Paulo State, Brazil, from March 2005 to March 2006. A total of 275 males were captured. Based on the analysis of the clasper length, gonad weight, clasper gland length, alar thorns and lobule diameter, the size-at-maturity was estimated to be 32 cm. There were 1049 females in the record. Size-at-maturity was calculated in 40 cm. Sexual resting females were observed. Gonadosomatic and hepatosomatic indexes varied significantly in both sexes throughout the year. However, ovulation, egg-laying and presence of sperm in the seminal vesicle were observed all year round. For this reason, an annual cycle with at least one peak in the sexual activity is proposed for this species.

The reproductive biology and cycle of Rioraja agassizi (Müller and Henle, 1841) (Chondrichthyes: Rajidae) in southeastern Brazil, SW Atlantic Ocean

Summary

Total length (TL) at first sexual maturity was estimated for Atlantoraja castelnaui and Dipturus chilensis from the south-western Atlantic Ocean. Total length at which 50% of the females were captured (50% c) was less than the TL at first sexual maturity (ML) in both species. Immature females are being captured and thus will not become sexually mature to reproduce because of early fishing mortality. Females of A. castelnaui and D. chilensis reach sexual maturity at TLs of 110–114 cm and 102–106 cm, respectively. Males mature with TL between 91 and 95 cm for A. castelnaui and between 83 and 87 cm for D. chilensis.

Size at first sexual maturity of two species of rajoid skates, genera Atlantoraja and Dipturus (Pisces, Elasmobranchii, Rajidae), from the south-western Atlantic Ocean

the population structure and reproductive biology of mustelus schmitti was analysed during autumn (1994, 1995) and spring (1994) in the rio de la plata oceanic front. the samples consisted mainly of adult males and immature females, indicating that nursery areas are situated elsewhere. in autumn, the highest female densities occurred between 36°s and 35°s, with densities decreasing further south, and high male densities occurred over all latitudes of the study area. in spring, both sexes occurred north of latitude 36°30′s. males attained maturity at 59 cm total length (tl), and females at 72 cm tl. litter size varied from one to ten in spring and two to nine in autumn, with embryos ranging from 9 to 26 cm and 7 to 26 cm tl respectively. the mean tl of embryos was significantly higher in spring (22 cm), suggesting that parturition occurs in late spring and summer. litter size was found to increase with female tl.

/pdf/reproductive-biology-and-seasonal-distribution-of-mustelus-rbi8yjodyc.pdf

Reproductive biology and seasonal distribution of Mustelus schmitti (Elasmobranchii : Triakidae) in the Rio de la Plata oceanic front, south-western Atlantic

A total of 459 individuals of Atlantoraja cyclophora were captured along the Rio Grande do Sul coast between latitudes 30o40'S and 34o30'S. Two surveys were performed, in the winter 2001 and in the summer/autumn 2002, using bottom-trawl between the depths of 100 and 600 m. This species occurred between 100 and 300 m deep, without significant differences in the frequency of occurrence and abundance (CPUE; kg/hour) between latitudes, depth and seasons. The sex ratio was not significantly different from 1:1 in all depths. In the study area, temperature ranged between 10.0 oC and 17.6 oC and salinity between 35.2 e 36.0 ppm. There was no correlation between CPUE and depth, temperature and salinity. Mean total length of females (53.2 cm) was significantly larger than males (50.9 cm). No differences were detected in mean total length between seasons, but mean total length was significantly larger in depths of 100 m and 200 m. The distribution of the frequencies of total length was asymmetric, indicating rareness or lack of juveniles in the samples.

/pdf/distribution-abundance-and-morphometry-of-atlantoraja-312ax2fnzh.pdf

María Cristina Oddone

Papers

Reproductive biology of Atlantoraja cyclophora (Regan 1903) (Elasmobranchii: Rajidae) off southern Brazil

The reproductive biology and cycle of Rioraja agassizi (Müller and Henle, 1841) (Chondrichthyes: Rajidae) in southeastern Brazil, SW Atlantic Ocean

Size at first sexual maturity of two species of rajoid skates, genera Atlantoraja and Dipturus (Pisces, Elasmobranchii, Rajidae), from the south-western Atlantic Ocean

Reproductive biology and seasonal distribution of Mustelus schmitti (Elasmobranchii : Triakidae) in the Rio de la Plata oceanic front, south-western Atlantic

Distribution, abundance and morphometry of Atlantoraja cyclophora (Regan, 1903) (Elasmobranchii: Rajidae) in southern Brazil, Southwestern Atlantic