Effects of natural and commercial feed on yield, growth and reproduction of Zebrafish (Danio rerio)

Abstract

Although zebrafish is used as a model species for understanding a number of biological functions and mechanisms, there is no practically successful information on the nutritional requirements. This study evaluated the effects of several natural and commercially available feeds and different feeding regimes on the growth, yield and reproductive performance of zebrafish (Danio rerio) and developed a standard diet. Zebrafish (n = 21) were stocked into each of 15 tanks (volume, 4 L); 3 tanks were assigned to each of 5 feeding combinations for a period of 62 days. Fish were fed with selective diet (e.g. diet 1: dried tubifex; diet 2: Artemia; diet 3: Artemia and commercial pellet feed; diet 4: Spirulina and commercial pellet feed; diet 5: Commercial pellet feed) twice daily for 62 days. Throughout the whole experimental period weight, length and survivability were recorded to determine the growth rate and compared among 5 different diets. The specific growth rate among various diets varied within (1.65±0.115%) to (0.39±0.102%) where highest value was found in fish fed with diet 5 (commercial pellet feed). Mean weight and length gain were greater in zebrafish fed diet 5 than diet 1, 2, 3 and 4. An excellent outcome happened for survival rate (%) in diets where highest survival rate was 100% in diet 4 and lowest value was (90.256±1.015) in diet 1. At the end of 62 days, 5 male and 5 female fish from each dietary treatment were pooled into breeding tanks and the effects of feeding combinations on reproductive performance were observed. Mean spawning success was significantly (p˂0.05) greater in zebrafish fed with diet 5 (Commercial pellet feed only) than in those fed with diet 1, 2, 3 and 4. Mean fertilization and hatching rates were higher in zebrafish fed with diet 3, 4 and 5 than zebrafish fed with diet 1 and 2. Zebrafish consuming the commercial pellet feed only, resulted in more viable offspring and more growth rate and it is a simpler feeding regime compared to other diets. The author recommended the commercial pellet feed to use in zebrafish culture for maximum growth and production of viable offspring under laboratory condition.