Fertilization in echinoderms

► In this article, we have reviewed some of the seminal and recent findings that feature similarities and differences in the fertilization of sea urchin and starfish. ► Unlike sea urchin, starfish eggs are fertilized before the completion of meiosis. ► The way the spermatozoa are activated and the Ca2+ waves are generated in the fertilized eggs are also subtly different. ► This review addresses their physiological significance and the role of the actin cytoskeleton in modulating the Ca2+ signals and sperm entry.