DEVELOPMENTS IN CAPTIVE BREEDING AND REARING OF Selene vomer

The Atlantic Lookdown, Selene vomer, is a popular fish in both the private and public aquaria trade. S. vomer belongs to the Carangidae family and has a wide distribution ranging from the northern Atlantic to the Caribbean. It is considered to be one of the most desirable roving, predatory fish in the aquarium trade.  Thousands of S. vomer are taken from the wild each year by public aquaria alone. Breeding S. vomer in captivity will reduce strain on wild populations and increase popularity of the fish in private and public aquaria. Here we present detailed methodology on the captive broodstock conditioning, egg collection, and larval rearing of this species.

A mature population of S. vomer broodstock (two males, eight females) is kept at the New England Aquarium's offsite holding facility in Quincy, MA in a 3,000 L recirculating seawater system. Broodstock were cannulated to determine gender and gonadal development. Females were injected with the slow release sGnRHa hormone implant OvaPlant (Syndel) and spawning ensued 36 hours post injection. The eggs were collected and transported to Roger Williams University, where they were sanitized, enumerated (N=30,000) and distributed among four isolated 200 L tanks and 12, 70 L tanks contained within two (6 tanks per system) 600 L recirculating systems. All tanks were outfitted with 40 um outflow screens and subjected to light aeration. The four 200 L tanks were initially non-recirculating, but converted to a recirculating system with mechanical and biological filtration by day 30. The eggs hatched 24 hours post fertilization. Larvae hatched without eyes, mouth, or gut, and transitioned to exogenous feeding by day 3. On day 3, limited by space, we reduced the larval density by 75% (~8,000 larvae remained) and fed Parvocalanus sp. copepods (5 nauplii and 2 adults/mL). Flexion occured at day 8-10, and post-flexion larvae were transitioned onto L-strain rotifers (Brachionus plicatilis; 5-10/mL) and instar I brine shrimp (Artemia sp.; 5-10/mL). 90% water changes were performed three times daily. By day 14, larvae were transitioned onto adult brine shrimp (10/mL; enriched with microalgae Tahitian Isochrysus galbana) and frozen copepods, and by day 33 exclusively ate Skretting marine pellets. Larvae settled by day 20, and juveniles reached marketable size (2-3 inches) by day 60, at which point they were relocated to four 1,000 L flow-through seawater tanks. Each tank housed 500 fish; water changes were performed twice daily and fish were fed three times daily. In total, raised over 2,500 fish from this one spawn, which were shipped to US-based wholesalers for distribution into public and private aquaria across the country.

The techniques gleaned from the rearing of this cohort are the first detailed procedures reported for this species. Due to the robustness of the larvae, with adequate space and proper filtration, we predict high yields of cultured S. vomer, upwards of at least 75%. The technology can be transferred to commercial farmers to increase cultured production of this and similar species to meet the growing demand of the aquarium trade.