Relative importance of parental diet versus larval nutrition on development and phenotypic plasticity of Pseudechinus huttoni larvae (Echinodermata: Echinoidea)

The relative importance of parental and larval diets on development of larvae of the sea urchin Pseudechinus huttoni was examined. Laval parameters measured included the size of body components, development rate, morphological phenotypic plasticity, mortality rate, protein, lipid, carbohydrate and energy contents. We also investigated the influence of parental nutrition on fecundity, egg diameter and the eggs' protein, lipid and carbohydrate content. For a period of one year, adult P. huttoni were fed kelp (Macrocystis pyrifera) ad libitum every second day as a low-quality diet, or kelp ad libitum every day plus cockle (Austrovenus stutchburyi) flesh once a week as a high-quality diet. Adults fed the high-quality diet produced larger eggs and larvae with a slower development rate, longer arms relative to the midline length, and lower protein, lipid and carbohydrate contents. In larvae, higher concentrations of planktonic diet led to larger body components, a faster development rate and shorter arms relative to midline length. This study showed that parental nutrition has an important effect on development rate and morphological phenotypic plasticity in larvae of P. huttoni.