The influence of salinity on the growth of juvenile shortnose sturgeon

The shortnose sturgeon Acipenser brevirostrum is a promising aquaculture ca ndidate, but optimal culture conditions remain to be defined. Given that sa linity is known to affect the growth performance of fish, we examined the e ffect of salinity on the growth of juvenile shortnose sturgeon in aquacultu re. Because the behavior and consequently the salinity exposure of juvenile s in the wild is largely unknown, the optimal culture salinity for growth o f juvenile shortnose sturgeon is difficult to predict. Juveniles (age, 16 m onths; mean weight, 273 g) were reared at four salinities (0, 5, 10, and 20 parts per thousand) for 10 weeks at 18 degreesC. Fish were fed a commercia l salmon feed (49% crude protein, 20% crude fat, 4% crude fiber) continuous ly at a rate of 0.75% of their body weight per day. Weight gain and feed co nversion rate (FCR) were significantly (P < 0.01) affected by salinity. Fis h reared at 0 parts per thousand showed significantly more weight gain and greater FCR than the fish raised at all other salinities. Fish reared at 20 parts per thousand exhibited the poorest growth, Thus, we conclude that sa linity may compromise the growth of juvenile shortnose sturgeon and suggest that, in commercial operations, salinity should be 0 parts per thousand.