TRIPLETAIL Loboted surinamensis: A PROMISING CANDIDATE SPECIES FOR U.S. MARINE AQUACULTURE

The Tripletail, Lobotes surinamensis, is a pelagic fish that frequents tropical and sub-tropical waters of all oceans. Tripletail are commonly found associated with floating debris and structures and make frequent incursions in bays and estuaries where they are targeted by recreational fishermen. Their increasing popularity has led to the development of fisheries regulations  in the southeast United States in recent years. Tripletail is appreciated as a gamefish but is also prized for its flesh of superior quality. The species is not prone to commercial harvest in the wild due to its solitary behavior but its potential as a food fish makes it a good candidate for marine aquaculture.

Research to develop tripletail aquaculture to date have focused on hatchery methods and a preliminary grow out trial. Photothermal conditioning of captive-held broodstocks promotes maturation of gametes as shown by the occurrence of fertilized spawns following hormonal induction, but spontaneous spawning has rarely been reported in a mass spawning tank, and the fertility of spawns is usually very low, suggesting that the final steps of gamete maturation, ovulation and spawning are disrupted in current culture conditions. Hormonal induction of spawning using GnRHa slow-release implants was effective at inducing ovulation of females that reached the final stages of vitellogenesis. The effects of GnRHa implants on spermiation could not be formally evaluated during trials conducted to date. A growth challenge in captivity conducted at low density revealed growth from an average mean weight of 12.9 g to 1,015 kg in 210 days. Phenotypic sexing is a challenge as the species does not have secondary sexual characters and males usually do not release milt during manual stripping. Sexing of females by ovarian biopsy using a catheter is challenging and prone to error, and this method does not allow positive identification of males while running the risk of damaging their efferent ducts. Sex identification of captive broodfish was achieved based on plasma levels of 11-ketotestosterone and Estradiol-17β and has been applied to allocate males and females to mating sets.

Informal interest in marketing this species has been expressed by restaurants and retailers but market potential would need to be characterized more rigorously as this species is new to most potential consumers due to the lack of commercial fishing. Protocols for effective spawning of captive broodstock, larviculture, and grow out still need to be designed so that the performance of this species in culture can be fully evaluated. Current data suggest that tripletail could become a successful species for commercial marine aquaculture assuming bottlenecks in the hatchery can be overcome.