Protrochophore

Protrochophore

 

the free-swimming larva of lower marine worms. It has the sensitive apical plate and preoral ciliate band that characterize the trochophore, but it has no anal opening. Examples of protrochophores are the Müller’s larva of certain polyclad tubellarians and the pilidium of nemertines.

References in periodicals archive ?
The initial swimming gastrula, or protrochophore, is completely ciliated but lacks any trochal band.