Abstract:The annual ovarian maturation cycle of spotted halibut Verasper variegatus was studied by employing light microscopy and morphometric methods. The spotted halibut features asynchronous oocyte development and batch spawnings. In sexually matured female, the oocyte growth consisted five phases, and the ovary maturation cycle consisted five stages accordingly. Gonadosomatic index (GSI), hepatosomatic index (HSI) and condition factor (CF) were all found to increase prior to, or during the peak phase of vitellogenic growth corresponding to the gonad development. The effective accumulated temperature for spotted halibut female broodstock is 1 050 d·℃. The results would highlight the reproductive cycle of captive female broodstocks of spotted halibut, and also serve as useful tools for broodstock breeding and determination of timing for hormone induced spawning.
