Pronunciation: TRO-ko-for LAR-va

Etymology: Trochophore is derived from two Greek roots that mean wheel (trochos, τροχός) and to bear (fero, φέρω). The reference is to the marginal ring of cilia on the larva.

The trochophore larva is a distinctive larval form of an assortment of protostomes (e.g. annelids, mollusks, bryozoans). Commonly found in the marine plankton, the trochophore is top-shaped with a marginal ring of cilia pygidium and a ciliary tuft near the mouth.

The trochophore larva of a Sipunculid. Note the ring of ciliary tufts.

By Jack R. Holt. Last revised: 01/03/2009