Reproductive biology and embryonic development of Squalus blainvillei in the eastern Mediterranean Sea

Scientia Marina

Vasiliki Kousteni¹  Persefoni Megalofonou¹ 

[1] Department of Biology, Section of Zoology-Marine Biology, University of Athens;

关键词: squalus blainvillei;    maturity;    fecundity;    embryonic development;   

DOI  :  10.3989/scimar.2011.75n2237

来源: DOAJ

【 摘 要 】

A total number of 526 Squalus blainvillei was sampled from the bottom trawl and bottom longline catchesin the eastern Mediterranean Sea from December 2004 to December 2009. Females outnumbered males and the overall sexratio was 1.26:1. Females ranged from 182 to 779 mm in total length and males from 180 to 799 mm. Both females andmales showed allometric growth (b > 3) and we found statistically significant differences in the relationship between lengthand weight. Out of the specimens examined, 36% of females and 63% of males were sexually mature. Males reached sexualmaturity at smaller sizes than females. The smallest sexually mature female was 523 mm in total length, while the smallestsexually mature male was 425 mm in total length. Mean length at 50% maturity was estimated at 564.4 mm for femalesand 457.7 mm for males. Sexually mature specimens of both sexes with mature gonads and high GSI were present in highproportions in every season of the year, which indicates a continuous reproductive cycle. Ovarian oocytes continued todevelop throughout gestation. Females carrying near-term embryos had large, equally developed ovarian oocytes, whichsuggests that they ovulate soon after parturition. Ovarian fecundity ranged from 1 to 7 and uterine fecundity ranged from 1to 6. Embryo length and yolk sac weight were negatively correlated.

【 授权许可】

Unknown