Mating System: polygynandrous (promiscuous) Echinoderms are
mainly gonochoristic (having separate sexes), with exceptions
among the asteroids, holothurians and ophuroids. Holothurians
possess a single gonad, crinoids lack distinct gonads, while
asteroids and echinoids have multiple gonads. Echinoderm
reproductive strategies vary from free spawning and indirect
development to brooding and direct development. Spawning is
probably a noctural event. Key Reproductive Features: seasonal
breeding ; gonochoric/gonochoristic/dioecious (sexes separate);
simultaneous hermaphrodite; sequential hermaphrodite; sexual ;
fertilization (External ); oviparous Parental investment ranges
from no care after the release of eggs for free spawning to
brooding the young. Brooding is found in polar and boreal
echinoderms and some deep sea echinoderms, where environments
are more difficult for the larvae. Parental Investment: pre-
fertilization (Provisioning); pre-hatching/birth (Provisioning:
Female, Protecting: Female) - Brusca, R., G