Salps: Thaliacea

Salps swim through the water by the movement of hairlike fibers on their bodies or by contracting muscles in the body wall to draw water into their intake opening and pump it out through their water-exit opening. Although they swim, salps are at the mercy of ocean currents for their entire lives.

When salps feed, water flows in through the mouth opening, through the mucus sheet covering the internal basket, and out the exit hole. Plankton and other small particles are caught on the mucus, which is moved to the mouth and eaten.

In some species of salps fertilized (FUR-teh-lyzed) eggs, or those that have been united with sperm, develop and hatch inside the animals. In other species the fertilized eggs hatch into larvae (LAR-vee), which are animals in an early stage that change form before becoming adults. Still other species alternate asexual and sexual stages of reproduction. Asexual (ay-SEK-shuh-wuhl) means without and sexual means with the uniting of egg and sperm for the transfer of DNA from two parents. An asexual generation buds into a sexual generation, which produces the eggs and sperm that fuse to produce the next asexual generation. This method of alternating asexual and sexual stages allows salps to reproduce extremely rapidly.