TANK SIZE AND AQUACULTURE MANAGEMENT INFLUENCE ON THE PRODUCTION OF GOLD FISH, Carassius auratus (L.), UNDER TROPICAL CONDITIONS

Jha Prithwiraj

Abstract
   Growth performance of gold fish Carassius auratus(L.) produced in tanks of different size and treated under different management regimes were compared. Tanks of two different size and make were used (concrete; capacity: 2000 l and earthen; capacity: 59650 l) for four management regimes: (1) live zooplankton fed to fish larvae in concrete (CLF) and earthen tanks (ELF); (2) application of poultry manure in concrete (CPM) and earthen tanks (EPM); (3) application of cow manure in concrete (CCD) and earthen tanks (ECD); and (4) a control treatment for concrete (CC) and earthen tanks (EC). Fish larvae (0.10 ± 0.007 g) were cultured for 11 weeks. Weight gain of gold fish was highest in the ELF treatment. There was a significant difference in the survival of gold fish among the treatments, ranging from 64.83% in CC to 93.40% in ELF. Significantly higher values of pH and dissolved oxygen were obtained in the live food and control treatments (for both concrete and earthen tanks), compared to the manured treatments. The concentration of total alkalinity, BOD, PO₄ – P, NO₃ – N and specific conductivity were significantly higher in EPM and ECD, compared to other treatments. The results indicate that introduction of live zooplankton into culture units resulted in higher growth of fish larvae. Better growth of cultured fish were obtained in larger earthen tanks compared to smaller concrete tanks through maintenance of better water quality and greater abundance of plankton.