Metatrochophore

Bright-field microscope image of metatrochophore of annelid Pomatoceros lamarckii (family Serpulidae)^[1]
ey = eyspot

A metatrochophore (/ˌmiːtəˈtroʊkəˌfɔːr, ˌmɛ-, -ˈtrɒ-, -koʊ-/;^[2][3]) is a type of larva developed from the trochophore larva of a polychaete annelid.

The metatrochophore of a deep-sea hydrothermal vent vestimentiferan has a foregut and a midgut. The foregut cells have several microvilli, basal bodies, and cilia, with e-dense granules dispersed in the apical cell region. The diameter of the midgut in one specimen was 50 μm and the lumen’s diameter was 7 μm, in which the cilia extended and e-dense material was found. The midgut cells had fewer cilia than the fore- and hindgut cells but exhibited an extensive, e-dense brush of microvilli and a nucleus in the apical third of the cell body. Additionally, the midgut contained a few bacteria in the lumen. ^[4]

Metatrochophores have a number of features trochophores lack, including eyespots and segments.

References

1. 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.
2. "Meta". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 2020-11-11. "Trochophore". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 2020-03-22.
3. "Meta". Dictionary.com Unabridged (Online). n.d. Retrieved 2016-01-24. "Trochophore". Dictionary.com Unabridged (Online). n.d. Retrieved 2016-01-24.
4. Bright, Monika. "The metatrochophore of a deep-sea hydrothermal vent vestimentiferan (Polychaeta: Siboglinidae)" (PDF). link.springer.com. Organisms, Diversity and Evolution. Retrieved 15 March 2024.