Sustainable Marine Aquaculture

INDUCED SPAWNING AND LARVAL-REARING OF FLORIDA POMPANO

Research Team:
Ken Riley (HBOI) - Principle Investigator
Chuck Weirich (USDA)
Megan Davis (HBOI)

The Florida pompano, Trachinotus carolinus, is a high-value marine finfish that exhibits several traits desirable for mariculture including rapid growth and tolerance to various culture conditions and systems. However, limited information exists with respect to methods for sustainable seed stock production. To address this issue, trials were conducted to initially characterize and evaluate captive reproduction of pompano via hormonal induction and to develop basic procedures for larval production.

Wild-caught Florida pompano were placed in two 12,000-L recirculating culture units maintained under natural photoperiod at 24-25 C during spring 2003. Each unit was stocked with 8 females and 7 males (mean weight = 1.3 and 0.7 kg, respectively). In each spawning trial ripe females (mean oocyte diameter > 400 µm) and all males were implanted with a 75-µg GnRHa pellet (36.8-144.2 µg/kg). Fish were spawned volitionally and eggs were collected and stocked into larval rearing tanks (24 C).

Results of two initial trials revealed that spawning commenced at approx. 36 h after implantation, occurring between 0200-0600 h. Spawning occurred thereafter for an additional four days. During the first trial 2.7 million eggs were produced (174,000/_), of which 13.6 % were floating (86.8 % fertilization). During the second trial 0.9 million eggs were produced (230,000/_) and 39.3 % were floating (71.3 % fertilization). Eggs hatched at approx. 30-36 h after fertilization. Larvae were fed rotifers beginning at 2 days post-hatch (DPH) and were weaned to Artemia by 10 DPH. Weaning to a formulated diet was complete at metamorphosis (22-25 DPH). Results of ongoing trials will be presented in addition to larval growth and mouthgape development as a means to select appropriate prey and feed items.