Volitional spawning of Florida pompano, Trachinotus carolinus, induced via administration of gonadotropin releasing hormoneanalogue (GnRHa)

Renewed interest in the culture of Florida pompano, Trachinotus carolinus, a high-value species first identified as an excellent candidate for mariculture over three decades ago, has occurred in recent years. To support the development of pompano mariculture, trials were conducted in 2004 and 2005 to evaluate captive reproduction of pompano via gonadotropin releasing hormone analogue (GnRHa) induction. Adult pompano collected seasonally beginning in 2003 from the wild were subjected to quarantine and feed training. Fish were held in recirculating tank systems (sex ratio 1:1) under controlled photo-thermal conditions and were sampled periodically to assess health and reproductive condition. To initiate spawning, ripe females (mean oocyte diameter > 500 μm) and males were implanted with a 75 μg GnRHa pellet. Fish spawned approximately 36 hours post-implantation and eggs were collected and stocked into incubation tanks (24–26°C) with hatching occurring approximately 30–36 hours post-fertilization. In 2004, three spawning trials were conducted resulting in the production of 4.4 million eggs, of which 979,000 (22.0%) were floating (mean fertilization rate 81.8%). In 2005, six trials were conducted resulting in the production of 5.8 million eggs, of which 2.5 million (42.7%) were floating (mean fertilization rate, 96.9%). Hatching rate of fertilized eggs in trials conducted ranged from 73.1–95.4%. Results to date indicate that pompano broodstock can be readily spawned in captivity over extended periods of time through GnRHa implantation. Although moderate variability in egg quality between spawning events has been observed, pompano produce relatively large quantities of eggs necessary for mass production of seed stock.