Comparative gonadogenesis and hormonal induction of spawning of cultured and wild mediterranean amberjack (Seriola dumerili, Risso 1810)

Abstract

The histological characteristics of wild and cultured Mediterranean amberjack gonads were studied during the first four years of their life cycle. No differences were found in the gonad development of both wild and captive males and females during the first and second year. In the third year, wild females showed more advanced oocyte development than captive females. In the fourth year, vitellogenic oocytes were noted for captive females. Fertilised eggs were obtained after a HCG hormone treatment of four- to nine-year old wild specimens. A smaller quantity of mature and fertilised eggs was also obtained through the spawning of hormone-treated four-year old captive broodstock specimens. Eggs in the stage of gastrulation died within eight hours following fertilisation.