Three day old operculate veliger larva of the green abalone.
Abalone larvae are lecithotrophic (deriving their nutrition from substance in the yolk) and do not feed while in the plankton. Once settled to become postlarvae, young abalone begin to feed on smaller elements of the microflora (including bacteria and smaller pennate diatoms).
Development rate and length of the swimming larval period are markedly influenced by temperature. Larvae of the temperate species, the green abalone, cultured at its optimum 22--24 o C, reach settling maturity in as few as 3.5 days. The cold water red abalone, at its optimum 14--16 o C, may reach settlement in five days (Leighton 1974).
Juvenile green abalone reared at 24--26 o C have reached 5 cm at one year of age (Leighton et al. 1981). A dietary transition occurs in juvenile abalone at an age of about four months. Macroalgae become principal foods. Many species are accepted, but the kelps Egregia (for green abalone) and Macrocystis (for red abalone) are widely used in aquaculture and appear to be their primary foods in nature.