The planktonic larva of certain invertebrates, including some mollusks and polychaete worms, having a roughly spherical body, a band of cilia, and a spinning motion.
- ‘The female releases her eggs one at a time, and one hatching the young animal will go through both a free-swimming trochophore and veliger stage, like all molluscs, before settling into an adult form in the muddy seafloor.’
- ‘Polychaetes usually have separate sexes; many polychaetes hatch into a particular type of planktonic larva, the trochophore, which later metamorphoses into a juvenile annelid.’
- ‘Another phylum, the Pogonophora, are also vermiform animals with a trochophore larva.’
- ‘The larva is a typical trochophore with apical organ, prototroch and metatroch of compound cilia, adoral ciliary zone and gastrotroch of separate cilia, and a pair of protonephridia; only the telotroch is missing.’
- ‘One widely-mooted suggestion is that planktotrophic larvae, typified by the annelidan trochophore and echinoid pluteus, existed long before the metazoan radiations evident in the Cambrian fossil record.’
Late 19th century: from Greek trokhos wheel + -phore.