THE GROWTH OF Macrobrachium rosenbergii FED COMMERCIAL FEEDS IN POND CAGES

A number of commercially available prawn and shrimp diets were tested in situ in response to a Hawaiian prawn industry mandate to conduct such an investigation under experimental conditions. In trial 1, feeds were delivered to juvenile Macrobrachium rosenbergii (initial weight 1.9 g) in cages within a commercial prawn pond. Animals were stocked at a density of 10/m 2 and fed at a rate of 5% of body weight daily for 10 weeks. There were 5 replicates in each treatment; group weights were taken. Diets varied in ingredients, leading to varying nutrient composition and degree of water stability. There was no statistical difference among 4 diets in promoting the highest average prawn gain of approximately 9 g. However, one of the 4 diets gave the highest increase in biomass (approximately 80 g). Best growth was seen on 27% protein/low water stability ration, followed in order by more water stable feeds of 41%, 28% and 44% protein. To evaluate the effect of water stability of different quality feeds on prawn production, trial 2 tested 3 commercial aquatic feeds in two forms each: 1) bound and water stable, and 2) unbound and less water stable. Fifty‐fifty combinations of the feeds in the two forms were also used. The trial was conducted as described in trial 1. There was no difference in growth of prawns fed bound or unbound forms of a given diet, nor among those fed the 3 types of feed. Results are applicable to animals of this size, reared in cages at this standing crop and fed at this rate.