Effects Of Four Stocking Densities And Three Diets On Growth And Survival Of Postlarval, Macrobrachium rosenbergii and M. acanthurus1

Effects of stocking density and three diets on growth and survival of 1 week post‐metamorphic Macrobrachium rosenbergii and M. acanthurus were studied. Experiments were conducted on shrimp held for 2 months in laboratory tanks under a controlled temperature, light, and feeding regime. Initial stocking densities were 215, 430, 645, and 860 shrimp/m2 tank bottom. Shrimp were fed Purina 20% protein marine ration at 5% body weight daily. Habitat was gravel bottom. M. rosenbergii survival was highest at 215 shrimp/m2, but overall growth was best at 430 shrimp/ m2. M. acanthurus survival and growth were very erratic. Two commercially available diets (Purina 25% marine ration, and Purina No. 1 trout chow) and a “natural” diet composed of chopped fish, shrimp, earthworm, rice, and mung beans were selected for dietary studies. Shrimp were stocked at 107.5 shrimp/m2 tank bottom. A three‐tiered habitat was added to reduce aggression and food competition. Shrimp were fed at 20% body weight daily for the first six weeks and 12% daily for the final two weeks. Trout chow produced the most rapid growth; maximum average increase in M. rosenbergii was from 0.03 g initially to 1.20 g after 2 months.