Biología reproductiva del gatuzo Mustelus schmitti Springer, 1939 (Chondrichthyes, Triakidae) en el área de Puerto Quequén, Provincia de Buenos Aires

Resumen

Reproductive biology of Mustelus schmitti, Springer, 1939 in Puerto Quequén, Buenos Aires Province. The reproductive biology of M. schmitti collected from the commercial bottom trawl fishery operating in Puerto Quequén, Argentina is investigated in the present study. The specimens were sampled seasonally during 2003–2004. The number of sharks collected was 637 (298 males and 339 females), including 190 pregnant females with 1,103 embryos. Size ranges for males were 419 – 819 mm total length (LT) and 417 – 951 mm LT for females. Total length and body weight relationship was different between sexes (P<0.05). In contrast, embryos did not show differences between sexes (P>0.05). Size frequency shows that females attain larger length and weight than males. Fifty percent (50%) of maturity size shows that males mature at a lower LT (567 mm) than females (598 mm). The left testis reached larger weight and length than the right one (P<0.01). Average values of the IG and IH per season varied significantly for males and females (P<0.05). Average values of the white and yellow ova per season showed significant differences (P<0.05) . The maximum diameter of the left oviducal gland was greater than the right one ( P<0.05) and both exhibit seasonal changes (P<0.05). At greater LT the females had more mbryos per brood (P<0.01) than bigger puppies (P>0.05).