Turkish Journal of Fisheries and Aquatic Sciences
2013, Vol 13, Num, 1 (Pages: 169-177)
Reproductive Biology of Spiny Dogfish Squalus acanthias, in the North Aegean Sea
C. Cigdem Yigin 1 ,Ali Ismen 1
1 Çanakkale Onsekiz Mart University, Marine Science and Technology Faculty, Çanakkale, Turkey
DOI :
10.4194/1303-2712-v13_1_20
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A total number of 620 Squalus acanthias was sampled from the bottom trawl catches in the North Aegean Sea, Saros
Bay from February 2005 to September 2008. The overall F/M ratio was 1.26:1. Females ranged from 17.1 cm to 117.5 cm in
total length (TL) and males from 20.8 cm to 121.6 cm. Females showed positive allometric growth (b>3) while males
indicated negative allometric growth (b<3). There were statistically significant differences in the relationship for total mass
versus TL, and liver mass versus TL between males and females. The smallest sexually mature female was 54.5 cm in TL,
while the smallest sexually mature male was 52 cm in TL. Mean length at 50% maturity was estimated at 56.4 cm for females
and 52.8 cm for males. The diameter of the yolky oocytes ranged between 0.5 mm and 46 mm, while the mass ranged
between 0.01 and 36.24 g. Hepatosomatic index (HSI) and gonadosomatic index (GSI) significanly increased with size in both
males and females. While the ranges of HSI and GSI values for males ranged between 1.93-14.09% and 0.01-34.35%, those
for females ranged between 1.63-17.17% and 0.01-96.50%, respectively. HSI reached the highest values in both sub-adult and
adult specimens, reflecting the role of the liver in the gonadal production.
Keywords :
Elasmobranchii, Saros Bay, maturity, reproductive cycle