Effects Of Feeding Frequency On Growth And Fecundity In An Ornamental Fish, Betta Splendens (Regan)

Abstract

Experiments were performed to investigate the influence of feeding frequency on growth, gonad weight and fecundity in an ornamental fish, Betta splendens. Five groups of 30-day-old juveniles (0.045±0.01 g; 14.43±2.2 mm) were fed either one meal in three days, one meal in two days, one meal per day, two meals per day or three meals per day for 77 days. Mean body length and weight increased linearly in all groups. However, the feeding, growth and fecundity rates increased with feeding frequency up to two meals a day, thereafter they declined. Fish fed once in three days consumed only 266 mg feed (dry weight) that was converted into 61 mg flesh (dry weight). Fish fed once in two days consumed 384 mg and gained 116 mg flesh. For fish fed once a day, 543 mg were consumed and converted to 175 mg flesh. For those fed twice a day, 1000 mg feed produced 279 mg flesh and for those fed three times a day, 886 mg food produced 242 mg flesh. The growth rate was significantly and drastically lower in all groups after spawning began, perhaps due to diversion of assimilated food energy for egg production. The gonad developed significantly (p<0.05) earlier in fish given at least one meal per day and weighed 85.5, 158 and 246.5 mg (wet weight) in fish fed once, twice and three times per day, respectively, on day 35 while it weighed only 56 and 93.5 mg on day 63 in fish fed once in three or two days, respectively. A similar trend was noted in the gonadosomatic index. Female B. splendens laid 274 and 454 eggs in groups fed once in three or two days, and 1833, 2202 and 632 eggs in groups fed once, twice or three times a day, respectively. Feeding three times a day resulted in total mortality of the spawners during the third spawn. Two meals a day elicited the maximum growth and reproductive performance and hence is considered optimal for B. splendens.