Early Induction of Spawning of Tautogs and Comparison of Growth Rates of Larvae from Early and Normally Spawned Broodstocks

Abstract

A reliable broodstock of spawning fish must be available year-round for finfish aquaculture to be a commercially viable venture. Two independent laboratory trials were conducted at Milford, Connecticut, and Narragansett, Rhode Island, to investigate spawning adult tautogs Tautoga onitis outside their normal spawning season by manipulating temperature and photoperiod. The spawning date for adult tautogs was successfully advanced by 2 months in each trial. Egg production rates were similar between the two trials, the peak numbers of eggs produced per day occurring between 5 and 8 d after spawning began. Although the methods used were slightly different at each laboratory, the results were similar, viable embryos being successfully hatched and cultured in each trial. Larval growth from the Rhode Island early-spawned fish was similar to that of larvae from fish spawned during the normal spawning season. The results of both trials indicate the possibility of maintaining multiple broodstocks and inducing them to breed at different times throughout the year.