Alviniconcha

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Alviniconcha
Two preserved specimens of Alviniconcha hessleri
Scientific classification
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Alviniconcha

Okutani & Ohta, 1988
Type species
Alviniconcha hessleri
Okutani & Ohta, 1988
Species

A. adamants, A. boucheti, A. hessleri, A. kojimai, A. marisindica, A. strummeri

Alviniconcha is a

foundational species found near hydrothermal venting fluid supplying their bacterial endosymbionts with vent derived compounds such as hydrogen sulfide. These snails can withstand large variations in temperature (5 - 33 °C),[4]
pH, and chemical compositions.

Description

The size of the shell varies between 20 mm up to 60 mm in shell height. The surface of the shell is studded with hairs on the

cryptic for many years, morphoanatomy studies on A. boucheti, A. kojimai, and A. strummeri have found distinguishing characteristics of the shell and head-foot regions.[5] These three species are the only ones known to cohabitate vent fields, all other species are found in isolated basins in the NW Pacific and Indian Oceans. Morphoanatomy has not been studied for A. adamants, A. hessleri, or A. marisindica, thus shell variation or morphology does not yet correspond to individual species.[2]

Life History

Knowledge gaps remain in the life history of Alviniconcha, however adult shell anatomy resembles

planktotrophic development.[4] Unlike the sister genus Ifremeria whose development includes a novel "Waren's" larval form, held within a brood pouch (absent in Alviniconcha).[6]

Species

Until 2014, Alviniconcha consisted solely of the species Alviniconcha hessleri, described in 1988. In 2014, increased recognition of genetic differences between populations resulted in the formal description of five

cryptic species within the former A. hessleri that were believed to be morphologically indistinguishable from each other but that have consistent differences in mitochondrial DNA sequences.[2] New research also suggests distributions of Alviniconcha in the SW Pacific are linked to geochemical gradients and endosymbiont chemical requirements.[7]

Species within the genus Alviniconcha include:

  • Alviniconcha adamantis - found in the relatively shallow seamounts (<1000m) of the Mariana's Arc and hypothesized to be the ancestor of all other extant Alviniconcha species. Hosts gammaproteobacterial endosymbionts.[8] S.B. Johnson, Warén, Tunnicliffe, Van Dover, Wheat, Schultz & Vrijenhoek, 2014
  • Alviniconcha boucheti - found in hydrothermal vents in the Manus, Fiji, and Lau basins ranging from 1300 to 2700 m in depth. Hosts epsilon-proteobacterial endosymbionts. Named after deep sea gastropod scientist Philippe Bouchet. S.B. Johnson, Warén, Tunnicliffe, Van Dover, Wheat, Schultz & Vrijenhoek, 2014
  • Alviniconcha hessleri - first Alviniconcha species to be described. Found at hydrothermal vents in the Mariana Trough at depths greater than 1400 m. Hosts gamma-proteobacterial endosymbionts. Most closely related to A. kojimai. Okutani & Ohta, 1988
  • Alviniconcha kojimai - found at hydrothermal vents of the Manus, Fiji, and Lau Basins ranging from 1480 to 2700 m in depth. Hosts both epsilon- and gamma-proteobacterial endosymbionts. S.B. Johnson, Warén, Tunnicliffe, Van Dover, Wheat, Schultz & Vrijenhoek, 2014
  • Alviniconcha marisindica - only Alviniconcha species found in the Indian Ocean, named by T. Okutani for the latin name for Indian Sea. Found specifically at vent sites on the Central Indian Ridge ranging from 2400 to 330 m in depth. Hosts epsilon-proteobacterial endosymbionts. Okutani, 2014
  • Alviniconcha strummeri - named after punk musician Joe Strummer of The Clash.[9] Only found in the Southern Lau Basin, specifically at the Tui Mall vents sites at a depth of 1850 m. Hosts both gamma- and epsilon- proteobacterial endosymbionts. S.B. Johnson, Warén, Tunnicliffe, Van Dover, Wheat, Schultz & Vrijenhoek, 2014

References

  • Healy, J.M. 1992, Dimorphic spermatozoa of the hydrothermal vent prosobranch Alviniconcha hessleri: systematic importance and comparison with other caenogastropods; Bull. Mus. Natl. His. Nat. Paris 4 sér A 14: 273-291
  • Desbruyères, D., M. Segonzac & M. Bright (eds.). 2006. Handbook of Deep-sea Hydrothermal Vent Fauna. Second Edition Denisia 18:1-544. (Copepods 316-355)(Polychaeta 183-296)

External links