ROTIFER (BRACHIONUS CALYCIFLORUS) COULD COMPETE FAVOURABLY WITH ARTEMIA NAUPLII AS ALTERNATIVE STARTER FOR AFRICAN CATFISH (CLARIAS GARIEPINUS)

Abstract

Background and Aim: Artemia nauplii and decapsulated cysts have remained the first choice for the first feeding of fish larvae, under intensive culture. The controlled production of Artemia nauplii which creates a dependence on the international cyst market - which is plagued by fluctuating prices, quality stability and high cost of shipping - have tremendously led to the scarcity of Artemia to farmers in the rural communities, and also sky-rocketed the cost of production to the very few who can afford it. Therefore, the need to find an alternative larvae starter feed that can compete side by side with Artemia nauplii and a sustainable zooplankton rearing technique that is inexpensive, relatively abundant and that can easily be carried out by fish farmers cannot be over-emphasized. Methods: Four-day old C. gariepinus larvae of initial length of 7.84mm and initial weight of 10mg were stocked into plastic aquaria and fed with five different diets: 100 % Artemia, 100 % B. calyciflorus, 50% Artemia + 50 % B. calyciflorus, 70 % Artemia + 30% B. calyciflorus and 30% Artemia + 70 % B. calyciflorus under ambient hatchery conditions for 35 days. Results: All growth parameters - Mean total length, Final mean weight, Percentage weight gain (PWG), Specific growth rate (SGR) and Percentage survival of fry were significantly different (P < 0.05) at the end of the feeding trial. Fry fed with combined diets performed better in weight and length than fry fed on a single diet. However, the mixture of B. calyciflorus at a higher proportion (70 %) and Artemia nauplii (30 %) proved to be very efficient in achieving good growth rate and survival index. Conclusion: Therefore, the authors posited that B. calyciflorus can compete favourably, side by side, with Artemia nauplii as an alternative starter for fish larvae and fry. The significance of the findings to aquaculture production of African catfish fingerlings are also discussed