Growth rates, nucleic acid concentrations, and [formula omitted] ratios of juvenile white shrimp, Penaeus vannamei boone, fed different algal diets

Abstract

Macro- and microalgae are potentially important food resources for penaeid shrimp inhabiting coastal nursery grounds and aquaculture ponds. However, there are few data on the nutritional contribution of different algal species to juvenile shrimp growth. In this study, changes in whole body weight, RNA and DNA concentrations, and RNA DNA ratios of juvenile white shrimp, Penaeus vannamei Boone, fed different algal species were compared to assess the nutritional contribution of each species 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 macroalga, Enteromorpha sp. after 5 days. In addition, RNA/DNA ratios were significantly greater ( p 0 ̌ .05 ) in abdominal muscle tissue from diatom-fed shrimp. About 76% of the variation in shrimp growth rate could be explained by changes in RNA concentration, whereas RNA DNA ratio accounted for about 80% of the variation in growth rate. Diatoms can contribute substantially to short-term shrimp growth, and are probably important in coastal nursery grounds and aquaculture ponds when other food resources are scarce or to supplement available food.