High Density Pond Culture of Silver Perch, Bidyanus bidyanus

Abstract

Silver perch, Bidyanus bidyanus, fingerlings (mean weight 4.6 g) were stocked at a density of 43,000 fish·ha·1 in a 0.3-ha static, aerated, pond and fed a 35% protein diet at daily rates up to 168 kg·ha·1 for 14 months. Concentrations of total ammonia-nitrogen rose rapidly in summer and remained above 1.0 mg·J·1• There was an outbreak of the mycotic disease, epizootic ulcerative syndrome, following a bloom of Microcystis and a rapid rise of pH to 9.4 and un-ionized ammonia-­nitrogen to 0.39 mg·J·1• An estimated 18.1% of fish harvested using a boat-mounted electrofisher had spinal damage and internal hemorrhaging. The overall survival rate was 69.7%, the mean weight 402 g and the food conversion ratio 2.3:1. A production of 12,146 kg·ha·1and a daily pro­duction rate of 27.8 kg·ha·1 are the highest yet achieved with silver perch, confirming its potential for intensive culture in ponds with limited water exchange.