The knowledge of gametogenesis is of paramount importance to develop a reliable technology for Atlantic bluefin tuna (Thunnus thynnus L.) (ABFT) rearing in captivity. The aims of this study were: a) to evaluate the capacity of male ABFT, confined in captivity before puberty, to finalize spermatogenesis; b) to compare germ cell proliferation between wild and captive ABFT. Testis samples were taken from: a) 13 juvenile ABFT reared in the North Adriatic Sea (Croatia); b) 30 adult ABFT reared in the central and western Mediterranean (Spain, Malta and Italy); c) 20 adult wild ABFT captured by tuna traps in Italy and Morocco. Samples were fixed in 10% formalin, dehydrated in ethanol and embedded in paraffin. Proliferating germ cells were identified through the immunohistochemical detection of proliferating cell nuclear antigen (PCNA). The first spiniform ray of the first dorsal spine was taken from the juvenile fish in order to estimate the age through the count of annual discontinuities. Juvenile ABFT captured before puberty were able to finalize spermatogenesis starting from 3 years of age. Germ cell proliferation was delayed in captive-reared ABFT specimen compared to wild individuals. These results seem to indicate that testis maturation can be anticipated in ABFT caught before puberty, but spermatogenesis is somewhat damaged in adult fish reared in captivity compared to wild individuals.
Captivity affects spermatogenesis in Atlantic bluefin tuna (Thunnus thynnus L.)
Zupa R;CORRIERO, Aldo;Pousis C;PASSANTINO, Letizia;
2011-01-01
Abstract
The knowledge of gametogenesis is of paramount importance to develop a reliable technology for Atlantic bluefin tuna (Thunnus thynnus L.) (ABFT) rearing in captivity. The aims of this study were: a) to evaluate the capacity of male ABFT, confined in captivity before puberty, to finalize spermatogenesis; b) to compare germ cell proliferation between wild and captive ABFT. Testis samples were taken from: a) 13 juvenile ABFT reared in the North Adriatic Sea (Croatia); b) 30 adult ABFT reared in the central and western Mediterranean (Spain, Malta and Italy); c) 20 adult wild ABFT captured by tuna traps in Italy and Morocco. Samples were fixed in 10% formalin, dehydrated in ethanol and embedded in paraffin. Proliferating germ cells were identified through the immunohistochemical detection of proliferating cell nuclear antigen (PCNA). The first spiniform ray of the first dorsal spine was taken from the juvenile fish in order to estimate the age through the count of annual discontinuities. Juvenile ABFT captured before puberty were able to finalize spermatogenesis starting from 3 years of age. Germ cell proliferation was delayed in captive-reared ABFT specimen compared to wild individuals. These results seem to indicate that testis maturation can be anticipated in ABFT caught before puberty, but spermatogenesis is somewhat damaged in adult fish reared in captivity compared to wild individuals.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
