PRODUCTION OF FINGERLING BIDYANUS-BIDYANUS (TERAPONIDAE) AT 2 DENSITIES IN EARTHEN PONDS IN AUSTRALIA

Fry of Bidyanus bidyanus, an Australian species known as silver perch, with a mean weight of 0.6 g were stocked at densities of 25,000 and 8 0,000/ha into 0.1-ha earthen ponds and cultured for 12 weeks. Each tre atment consisted of three replicate ponds. The ponds were aerated for 11 h each day and no water was added. Fish were fed a formulated diet, containing 35% protein, twice daily at rates up to 5% of estimated bi omass. Fry readily accepted the feed. Mean water temperatures were 26. 6, 24.1, and 22.0-degrees-C in February, March, and April, respectivel y. Approximately 31,000 fingerlings were harvested. Fish stocked at 25 ,000/ha (mean total length, 98.1 mm; mean weight, 16.0 g) were signifi cantly larger (P < 0.01) than fish stocked at 80,000/ha (75.9 mm; 7.4 g). Stocking density did not affect mean survival (99.7, 98.7%) or the food conversion ratio (1.2, 1.1). The results demonstrate that large numbers of silver perch fingerlings can be produced when cultured in e arthen ponds and fed a formulated diet.