Evaluation of Six Feeding Regimens for Survival and Growth of Shortnose Sturgeon Fry

Abstract

The shortnose sturgeon Acipenser brevirostrum is a federally listed endangered fish species cultured for recovery efforts. Since high mortality and labor costs are associated with first-feeding sturgeon culture, particularly during the period of dietary conversion from live to formulated feed, we investigated the effects of six feeding regimens on the survival and growth of cultured shortnose sturgeon fry. During the 30-d trial, five replicate groups (100 fish/replicate) of first-feeding shortnose sturgeon were fed according to six regimens: (1) live feed (live nauplii of brine shrimp Artemia spp.); (2) formulated (commercially formulated salmonid starter diet); (3) alternate (alternate feedings of the live and formulated feed); (4) transition (slow transition from the live to the formulated feed); (5) automatic (cofeeding the live and formulated feeds with the use of an automatic feeder); and (6) starvation (no feeding). Significantly greater survival rates were observed in the transition (97.4%), automatic (96.0%), alternate (93.8%), and live feed regimens (92.6%) than in the formulated (71.8%) and starvation regimens (31.6%). Length and weight of fish in the alternate (52.4 mm and 0.62 g), automatic (52.3 mm and 0.63 g), transition (46.9 mm and 0.48 g), and live feed regimens (46.4 mm and 0.43 g) were significantly greater than the length and weight of fish in the formulated (31.4 mm and 0.18 g) and starvation regimens (20.6 mm and 0.04 g). Fish weights in the alternate and automatic regimens were significantly greater than those in the live feed regimen. Based on the results of this study, we recommend the automatic regimen for first-feeding shortnose sturgeon culture. This feeding regimen produced heavier fish than the live feed regimen, appeared to reduce labor costs compared with the other feeding regimens, and alleviated possible complications associated with diet conversion.