Ovarian development of the spotted rose snapper (Lutjanus guttatus)
Ovarian development was compared between captive and wild caught snapper (Lutjanus guttatus). From December to June, 2-4 captive females and 6-10 wild caught females were sampled. For each fish sacrificed, gonadal somatic index (GSI), size and nuclear position of 100 oocytes from fresh samples, stage of development of 100 histologically processed oocytes and expression of a vitellogenin gene (vtg) in the liver were determined. Wild fish were found with vitellogenic oocytes and elevated vtg expression in every month except Jan., while fish in captivity only exhibited stage V of vitellogenesis in June and vtg expression from April through to June. Vitellogenesis appeared to be delayed in captive fish, either due to environmental conditions or reproductive dysfunction, but suggests that spawning in captivity is possible.