Trochophore



A trochophore is a type of free-swimming planktonic marine larva with several bands of cilia.

By moving their cilia rapidly, they make a water eddy to control their movement, and to bring their food closer in order to capture it more easily.

Occurrence
Trochophores exist as a larval form within the trochozoan clade, which include the entoprocts, molluscs, annelids (including echiurans and sipunculans) and nemerteans. Together, these phyla make up part of the Lophotrochozoa; it is possible that trochophore larvae were present in the life cycle of the group's common ancestor.

Etymology
The term trochophore derives from the ancient Greek, meaning "wheel", and   — or   —, meaning 'to bear, to carry', because the larva is bearing a wheel-shaped band of cilia.

Feeding habits
Trochophore larvae are often planktotrophic; that is, they feed on other plankton species.

Life cycle
The example of the development of the annelid Pomatoceros lamarckii (family Serpulidae) shows various trochophore stages (image: D-F): D - early trochophore ; E - complete trochophore ; F - late trochophore ; G - metatrochophore.