Evaluation of different diets to replace Artemia nauplii for larval rearing of giant freshwater prawn (Macrobrachium rosenbergii)

Abstract

A study was conducted on Macrobrachium rosenbergii larvae to evaluate the efficiency of different diets to replace Artemia nauplii in the feeding scheme. The study included two experiments performed at pilot scale in 12-L tanks using a recirculating system. Larval stocking density was 100 larvae/L. After 7 days of feeding by Artemia nauplii, different diets, included wet and dry diets and decapsulated Artemia cysts, were tested to replace Artemia nauplii. An extra treatment using only decapsulated Artemia cysts throughout the complete larval rearing was also included. The results showed that feeding larvae exclusively decapsulated cysts for the complete rearing cycle was not appropriate. When gradually replacing up to 50% of the Artemia nauplii ration with wet or dry diets, good results in terms of growth, survival and quality of the larvae were obtained, similar to the control treatment receiving only Artemia nauplii. However, abruptly replacing 50% of the Artemia nauplii ration with artificial diets negatively affected larval development. Weaning could start from larval stage V, with about 25% of the Artemia nauplii replaced with artificial diet. Subsequently, the weaning ration could be increased up to 50% from stage IX to postlarva stage. Artificial diets should be provided in different particle size ranges based on the larval stage, gradually increasing from 250 to 1000 μm from stage V to postlarva stage. The results obtained in the present study may aid future research and serve as a baseline for further optimization of feeding strategies in prawn larviculture.