The Effects Of Algal Supplements On Static System Culture Of Macrobrachium rosenbergii (De Man) Larvae1,2

Abstract

ABSTRACTThe value of algal supplements in rearing Macrobrachium rosenbergii larvae in static water systems was investigated. Larvae were reared in 60 liter fiberglass rounded bottom tanks at concentrations ranging from 50 to 67 larvae/liter. Standard culture methods (used by Marine Resources Research Institute) and feeds (Artemia salina nauplii, TetraMin, fish eggs) were utilized throughout the study. The three major groups of phytoplankters evaluated included the Chlorophyceae (Nannachloris oculata, Dunaliella tertiolecta, Chlorella sp.), the Chrysophyceae (Isochrysis galbana, Pseudoisochrysis paradoxa), and the Bacillariophyceae (Skeletonema costatum, Phaeodactylum tricornutum). Algal supplements were added to produce concentrations of 20,000 to 1,200,000 cells/ml in the larval culture tanks. Three replicate cultures per algal species were maintained and compared to control replicates.Algal supplements increased survival of larvae and production of postlarvae and decreased length of time to metamorphosis. P. tricornutum, I. galbana, and P. paradoxa appear to be the most valuable supplements tested to date. These treatments routinely resulted in approximately 30% greater survival and between 40 and 60% more postlarvae than control treatments. Possible mechanisms for the algal enhancement of M. rosenbergii larval culture are discussed.