Trochophore
A - episphere
B - hyposphere
1 - ganglia
2 - apical tuft
3 - prototroch
4 - metatroch
5 - nephridium
6 - anus
7 - protonephridia
8 - gastrointestinal tract
9 - buccal opening
10 - blastocoele
A trochophore (/ˈtroʊkəˌfɔːr, ˈtrɒ-, -koʊ-/[1][2]) 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
[edit]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
[edit]The term trochophore derives from the ancient Greek τροχός (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
[edit]Trochophore larvae are often planktotrophic; that is, they feed on other plankton species.
Life cycle
[edit]
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.
References
[edit]- ^ "Trochophore". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 2020-03-22.
- ^ "Trochophore". Dictionary.com Unabridged (Online). n.d. Retrieved 2016-01-21.
- ^ Bailly, Anatole. "Greek-french dictionary online". www.tabularium.be. Retrieved 2017-01-24.
- ^ McDougall, Carmel; Chen, Wei-Chung; Shimeld, Sebastian M.; Ferrier, David E. K. (2006). "The development of the larval nervous system, musculature and ciliary bands of Pomatoceros lamarckii (Annelida): heterochrony in polychaetes". Frontiers in Zoology. 3 (1): 16. doi:10.1186/1742-9994-3-16. PMC 1615870. PMID 17032451.
- ^ Jackson, Daniel J.; Wörheide, Gert; Degnan, Bernard M. (2007). "Dynamic expression of ancient and novel molluscan shell genes during ecological transitions". BMC Evolutionary Biology. 7 (1): 160. Bibcode:2007BMCEE...7..160J. doi:10.1186/1471-2148-7-160. PMC 2034539. PMID 17845714.
External links
[edit]
- Nielsen, Claus (2018-07-01). "Origin of the trochophora larva". Royal Society Open Science. 5 (7): 180042. Bibcode:2018RSOS....580042N. doi:10.1098/rsos.180042. ISSN 2054-5703. PMC 6083724. PMID 30109065.