Broodstock development through regulation of photoperiod and controlled breeding of silver pompano, Trachinotus blochii (Lacepede, 1801) in India

The silver pompano, Trachinotus blochii is recognised as a promising species for mariculture. In India, broodstock development, controlled breeding and seed production of silver pompano was achieved for the first time at Mandapam Regional Centre of Central Marine Fisheries Research Institute. Sub-adult fishes collected from the wild were grown in circular sea cages of 6 m diameter and 3.5 m depth. Twelve fishes were selected from a sea cage and acclimatized to laboratory conditions. Among these, four fishes (1 female and 3 males) were pre-conditioned to sexual maturity in a 10 t FRP tank with photoperiod control facility (2000 lux; 14 L: 10 D). In about 2 months, the gonads reached right stage for spawning. The brooders were administered human chorionic gonadotropin (hCG) intramuscularly, at a dosage of 350 IU kg body weight(-1). A total of 5 experiments were conducted and successful spawnings were obtained resulting in the production of fertilized eggs. The time taken for spawning ranged from 30-36 h. The total number of eggs spawned ranged from 0.08 to 0.184 million. The fertilization percentage varied from 75 to 95. Freshly spawned eggs measured above 900 mu. The success obtained in all the consecutive five experiments indicated that predictable spawnings of pompano could be achieved by employing the techniques developed.