Abstract
In a study of chemical inducers for larval settlement and metamorphosis in the sea urchins Pseudocentrotus depressus and Anthocidaris crassispina, eight out of 16 commercially-available fatty acids (five saturated and 11 unsaturated) induced larval responses. Fatty acids lacking or having only one double bond in the molecule had no inducing effect. Highly unsaturated fatty acids induced high rates of larval responses, but caused larval abnormalities at higher concentrations. The responses of the sea urchin larvae to the assayed fatty acids was highly specific with respect to the chain length and the number of double bonds in the molecule.
