Enhancing Black Crappie Growth by Co-culturing with Bluegills

摘要

Crappies Pomoxis spp. are popular sports fish in the USA and desirable as a food fish. Information on the food production of crappies is limited due to culturing and feed intake challenges. Observations indicated that crappies tend to feed more aggressively in co-culture with Bluegills Lepomis macrochirus or Bluegill hybrids. This study tested this observation by stocking 25 Black Crappies P. nigromaculatus (mean, 5 g) per tank into 16 tanks of a water recirculation aquaculture system and randomly adding zero, one, two, or four Bluegills per tank with four replications per treatment. Fish were fed at 0800, 1200 and 1600 hours 6 d/week. Feed intake was measured daily and growth was monitored by obtaining biweekly biomass by species. After 12 weeks, feed intake and feed conversion ratio tended to improve with the increasing treatment number of Bluegills. Significant differences in these occurred between the zero and the treatment with four Bluegills. Black Crappie co-cultured with Bluegills had increases in weight gain of 15-18% compared with those cultured without Bluegills. Improved growth trends in final weights and specific growth rate also occurred in the co-cultured Black Crappies.