Preliminary larval culture protocols of Hogfish

Abstract Objective The Hogfish Lachnolaimus maximus is a commercially and recreationally important marine fish species with recent success in captive spawning and larval culture. However, optimal early culture protocols remain undefined. Establishing best culture protocols, from stocking of eggs through early larval stages, is crucial to determine the feasibility of Hogfish aquaculture for stock enhancement and food fish production. Methods Culture protocols were evaluated for captive-spawned larval Hogfish in a series of 15-d experiments comparing rotifer (Brachionus plicatilis) and copepod nauplii (Parvocalanus crassirostris) feeding densities, the duration of copepod provision, and the effects of greening the water with live phytoplankton (Tisochrysis lutea) at different cell densities. Hatching success and survival to first feeding were further examined under varying stocking densities and water flow regimes. Results Feeding trials demonstrated increased growth and survival with increased feeding densities and longer durations of copepod nauplii provision compared with rotifers alone. Doubling the feeding density of rotifers (20 versus 10/mL) did not improve larval survival. Addition of T. lutea at 300,000 and 500,000 cells/mL led to increased larval survival, with the highest survival (∼15% to 15 d posthatch) observed with the combined best culture practices of previous trials. Larval Hogfish exhibited a 60–80% hatching success at densities up to 400 embryos/L, with survival to first feeding unaffected by water flow regime. Conclusions Cumulative performance among all trials suggests greatest survival of Hogfish larvae would occur when fed 5/mL of both rotifers and copepods nauplii, providing copepod nauplii through at least 12 d posthatch, and with the addition of phytoplankton from 300,000 to 500,000 cells/mL.