GROWTH-RATES, NUCLEIC-ACID CONCENTRATIONS, AND RNA DNA RATIOS OF JUVENILE WHITE SHRIMP, PENAEUS-VANNAMEI BOONE, FED DIFFERENT ALGAL DIETS

Macro-and microalgae are potentially important food resources for pena eid shrimp inhabiting coastal nursery grounds and aquaculture ponds. H owever, there are few data on the nutritional contribution of differen t algal species to juvenile shrimp growth. In this study, changes in w hole body weight, RNA and DNA concentrations, and RNA/DNA ratios of ju venile white shrimp, Penaeus vannamei Boone, fed different algal speci es were compared to assess the nutritional contribution of each specie s to shrimp growth. Shrimp fed a diatom culture composed primarily of Chaetoceros sp. were significantly heavier (p < 0.05) than shrimp fed a monoculture of the green alga, Nannochloropsis oculata, fronds from the leafy macroalga, Ulva sp., or fronds from the filamentous macroalg a, Enteromorpha sp. after 5 days. In addition, RNA/DNA ratios were sig nificantly greater (p < 0.05) in abdominal muscle tissue from diatom-f ed shrimp. About 76% of the variation in shrimp growth rate could be e xplained by changes in RNA concentration, whereas RNA/DNA ratio accoun ted for about 80% of the variation in growth rate. Diatoms can contrib ute substantially to short-term shrimp growth, and are probably import ant in coastal nursery grounds and aquaculture ponds when other food r esources are scarce or to supplement available food.