Effect of optimum Spirulina along with different levels of vitamin C incorporated diets on growth, reproduction and coloration in goldfish Carassius auratus (Linnaeus, 1758)

Abstract

Effect of optimum Spirulina (30 g kg-1 diet) with different levels of vitamin C (50, 100, 200 and 300 mg kg-1 diet) on growth, gonad weight, reproduction and coloration were studied in the goldfish, Carassius auratus for 120 days. The feed consumption and growth parameters were high during pre-spawning period, which significantly declined (p<0.05) during post-spawning period. However, the feeding rate and the feed conversion ratio showed opposite trends. Test fish fed with Spirulina +200 mg vitamin C kg-1 diet significantly enhanced growth, gonad weight, fecundity and coloration (p<0.01) as compared to other diets. The supplementation of excess vitamin C in Spirulina feed significantly reduced (p<0.01) the gonad weight and fecundity in C. auratus. During the experiment, the control fish spawned only once with few eggs per spawn while other groups spawned twice with a greater number of eggs per spawn. The females fed with Spirulina diet laid 703 eggs in two spawnings as compared to 1000 eggs in fish fed with Spirulina and 200 mg vitamin C kg-1 diet. The fish treated with other combinations laid fewer eggs than those fed Spirulina and 200 mg vitamin C kg-1 diet.