The reproductive biology of Scyliorhinus canicula in the Bristol Channel, U.K. |
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| Authors: | J R Ellis S E Shackley |
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| Institution: | Marine Fish and Fisheries Laboratory, School of Biological Sciences, University of Wales Swansea, Singleton Park, Swansea, SA2 8PP, U.K. |
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| Abstract: | Among 972 Scyliorhinus canicula , the overall sex ratio (males:females) was 1:1·23. Males matured between 490 and 540 mm L T with 50% maturity at 520 mm. Females matured between 520 and 640 mm L T with 50% maturity at 550 mm. Female gonadosomatic index peaked in May. Fecundity increased with fish length. The egg laying season lasted 10 months with a peak in June and July. The importance of erect, sessile invertebrates such as bryozoans, poriferans and hydroids as egg-case deposition sites has been established. Recently hatched fish were born in an equal sex ratio and at a mean length of 100·5 mm and mean weight of 3·07 g. One intersexual fish is described. |
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| Keywords: | Scyliorhinidae Elasmobranchii reproductive biology maturity oocytes egg-case deposition intersexuality gonadosomatic index |
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