In Virginia and throughout the United States, freshwater and saltwater finfish and shrimp aquaculture is expanding rapidly. During the cultivation of most marine finfish and shrimp species – as well as some freshwater species – live feeds are an essential component during the larviculture stage. During larviculture, the rotifer is the most commonly used live feed upon transition of the larvae from endogenous (internal energy reserves) to exogenous (external) feeding. Upon completion of the rotifer stage, the most commonly used live feed prior to conversion of the larva to a dry diet is Artemia.

Live feeds are an integral component in the cultivation of most marine finfish species during larval stages. The first live feed that has demonstrated acceptability for most marine species, and which can typically be raised on a commercial scale, is the rotifer Brachionous spp. While approximately two thousand species of rotifers have been identified, most culturists rely upon the marine rotifers Brachionus plicatilis (L-strain) with a size range of 200 to 360 μm and B. rotundiformis (s-strain) with a size range of 150 to 220 μm (see figure 1). Rotifers are favored due to their size, their ability to be raised in mass cultures, and the fact that their nutrient composition can be quickly improved through the use of specialized enrichment diets.