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 Greekτροχός (trókhos), meaning "wheel", and φέρω (phérō) — or φορέω (phoréō) —, meaning 'to bear, to carry',[3] 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.
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.
9-hour-old trochophore of the marine gastropod Haliotis asinina (sf - shell field)[5]Ontogeny of the Polyplacophora: First image shows the trochophore, second shows the stadium in metamorphosis, third is a juvenile (scanning electron microscope: SEM)
