Telotroch

Telotroch is the free-swimming stage of members of the order Sessilida.

Sessilida are ciliates of the subclass Peritrichia.

A sessile individual can turn into a motile one to migrate to a better place.

[1] Another definition of telotroch: a posterior tuft of cilia in larvae of some animals.

See trochophore larva and hemichordates for references.