Comb Jellies: Ctenophora

Comb jellies control water flow around themselves for movement by jet propulsion and "flying," for the capture and eating of prey, and for escaping from predators. Comb jellies either actively seek their prey or wait in ambush for it. Their long tentacles have muscular cores and a covering that contains sticky cells. The tentacles trail through the water or are twirled about by various circular movements of the body. When the tentacles touch prey, the sticky cells burst and discharge a strong, sticky material. Comb jellies that have very short tentacles trap plankton in mucus on their body surface, and the particles are carried to the jelly's mouth by currents produced by hairlike fibers.

Most comb jellies make both eggs and sperm. Only a few species have separate sexes. Most comb jellies release their eggs and sperm into the water. Fertilization (FUR-teh-lih-ZAY-shun), or the joining of egg and sperm to start development, takes place outside the body. In some species, however, fertilization takes place inside the body. Almost all comb jellies fertilize (FUR-teh-lyze) themselves. The larvae swim freely during their transformation into adults.