{{Short description|Genus of gastropods}} {{Automatic taxobox | taxon = Alviniconcha | image = Alviniconcha hessleri.jpg | image_caption = Two preserved specimens of ''Alviniconcha hessleri'' | authority = Okutani & Ohta, 1988 | type_species = ''Alviniconcha hessleri'' | type_species_authority = Okutani & Ohta, 1988 | subdivision_ranks = Species | subdivision = {{Linked species list | Alviniconcha adamantis | S. B. Johnson, Warén, Tunnicliffe, Van Dover, Wheat, T. F. Schultz & Vrijenhoek, 2014 | Alviniconcha boucheti | S. B. Johnson, Warén, Tunnicliffe, Van Dover, Wheat, T. F. Schultz & Vrijenhoek, 2014 | Alviniconcha hessleri | Okutani & Ohta, 1988 | Alviniconcha kojimai | S. B. Johnson, Warén, Tunnicliffe, Van Dover, Wheat, T. F. Schultz & Vrijenhoek, 2014 | Alviniconcha marisindica | Okutani, 2014 | Alviniconcha strummeri | S. B. Johnson, Warén, Tunnicliffe, Van Dover, Wheat, T. F. Schultz & Vrijenhoek, 2014 }} | subdivision_ref = <ref name="WoRMS"/> }}
'''''Alviniconcha''''' is a genus of deep water sea snails, marine gastropod mollusks in the family Paskentanidae.<ref name="WoRMS">{{cite WoRMS |title=''Alviniconcha'' |id=449922 |access-date=14 September 2024}}</ref> These snails are part of the fauna of the hydrothermal vents in the Indian and Western Pacific Ocean.<ref name="Shannon et al 2014">{{cite journal|last1=Johnson|first1=Shannon B.|last2=Warén|first2=Anders|last3=Tunnicliffe|first3=Verena|last4=Dover|first4=Cindy Van|last5=Wheat|first5=C. Geoffrey|last6=Schultz|first6=Thomas F.|last7=Vrijenhoek|first7=Robert C.|title=Molecular taxonomy and naming of five cryptic species of ''Alviniconcha'' snails (Gastropoda: Abyssochrysoidea) from hydrothermal vents|journal=Systematics and Biodiversity|volume=13|issue=3|date=2014|pages=278–295|doi=10.1080/14772000.2014.970673|s2cid=85253352 |doi-access=free}}</ref> These and another genus and species within the same family (''Ifremeria nautilei'') are the only known currently existing animals whose nutrition is derived from an endosymbiotic relationship with a member of bacteria from phylum Campylobacterota (formerly Epsilonproteobacteria) and Gammaproteobacteria, occurring as endosymbionts within the vacuoles of ''Alviniconcha'' ctenidia (or molluscan gills).<ref>Yohey Suzuki, Takenori Sasaki, Masae Suzuki, Yuichi Nogi, Tetsuya Miwa, Ken Takai, Kenneth H. Nealson & Koki Horikoshi (September 2005) "Novel Chemoautotrophic Endosymbiosis between a Member of the Epsilonproteobacteria and the Hydrothermal-Vent Gastropod ''Alviniconcha'' aff. ''hessleri'' (Gastropoda: Provannidae) from the Indian Ocean". ''Applied and Environmental Microbiology'', 71(9): 5440-5450. {{doi|10.1128/AEM.71.9.5440-5450.2005}}</ref> All species of ''Alviniconcha'' are thought to be 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 ({{cvt|5|-|33|°C}}),<ref name="Waren">{{cite journal |last1=Waren |first1=Anders |last2=Bouchet |first2=Philippe |title=New records, species, genera, and a new family of gastropods from hydrothermal vents and hydrocarbon seeps |journal=Zoologica Scripta |date=January 1993 |volume=22 |issue=1 |pages=1–90 |doi=10.1111/j.1463-6409.1993.tb00342.x |s2cid=83548576 }}</ref> pH, and chemical compositions.
==Description== The size of the shell varies between {{cvt|20|mm}} up to {{cvt|60|mm}} in height. The surface of the shell is studded with hairs on the periostracum, which ranges from a yellow/green to brown coloring. However, this thin periostracum is often missing or degraded due to high temperatures and chemical reductants found in nearby venting fluid. While ''Alviniconcha'' has been considered 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.<ref name="Laming">{{cite journal |last1=Laming |first1=Sven R. |last2=Stephane |first2=Hourdez |last3=Cambon-Bonavita |first3=Marie-Anne |last4=Pradillon |first4=Florence |title=Classical and computed tomographic anatomical analyses in a not-so-cryptic Alviniconcha species complex from hydrothermal vents in the SW Pacific |journal=Frontiers in Zoology |date=May 2020 |volume=17 |issue=12 |page=12 |doi=10.1186/s12983-020-00357-x |pmid=32391066 |pmc=7203863 |doi-access=free }}</ref> 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.<ref name="Shannon et al 2014"/>
==Life history== Knowledge gaps remain in the life history of ''Alviniconcha'', however adult shell anatomy resembles planktotrophic development.<ref name="Waren" /> Unlike the sister genus ''Ifremeria'' whose development includes a novel "Waren's" larval form, held within a brood pouch (absent in ''Alviniconcha'').<ref>{{cite journal |last1=Reynolds |first1=Kyle C |last2=Watanabe |first2=Hiromi Kayama |last3=Strong |first3=Ellen |last4=Sasaki |first4=Takenori |last5=Uematsu |first5=Katsyuki |last6=Miyake |first6=Hiroshi |last7=Kojima |first7=Shigeaki |last8=Suzuki |first8=Yohey |last9=Fujikura |first9=Katsunori |last10=Kim |first10=Stacy |last11=Young |first11=Craig M |title=New Molluscan Larval Form: Brooding and Development in a Hydrothermal Vent Gastropod, Ifremeria nautili (Provannidae) |journal=Biological Bulletin |date=August 2010 |volume=219 |issue=1 |pages=7–11 |doi=10.1086/BBLv219n1p7 |pmid=20813984 |s2cid=34778665 }}</ref>
==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.<ref name="Shannon et al 2014"/> New research also suggests distributions of ''Alviniconcha'' in the SW Pacific are linked to geochemical gradients and endosymbiont chemical requirements.<ref>{{cite journal |last1=Beinart |first1=Roxanne A. |last2=Sanders |first2=Jon G. |last3=Faure |first3=Baptiste |last4=Sylva |first4=Sean P. |last5=Lee |first5=Raymond W. |last6=Becker |first6=Erin L. |last7=Gartman |first7=Amy |last8=Luther III |first8=George W. |last9=Seewald |first9=Jeffrey S. |last10=Fisher |first10=Charles R. |author11-link=Peter Girguis |last11=Girguis |first11=Peter R. |title=Evidence for the role of endosymbionts in regional-scale habitat partitioning by hydrothermal vent symbioses |journal=Proceedings of the National Academy of Sciences of the USA |date=November 2012 |volume=109 |issue=47 |pages=E3241-50 |doi=10.1073/pnas.1202690109 |pmid=23091033 |pmc=3511114 |doi-access=free }}</ref>
Species within the genus ''Alviniconcha'' include: * '''''Alviniconcha adamantis''''' - found in the relatively shallow seamounts (less than {{cvt|1000|m}}) of the Mariana's Arc and hypothesized to be the ancestor of all other extant ''Alviniconcha'' species. Hosts gammaproteobacterial endosymbionts.<ref name="Breusing">{{cite journal |last1=Breusing |first1=Corinna |last2=Hagen Klobsunik |first2=Nathan |last3=Hauer |first3=Michelle A |last4=Beinart |first4=Roxanne A |title=Genome assembly of the chemosynthetic endosymbiont of the hydrothermal vent snail Alviniconcha adamantis from the Mariana Arc |journal=G3: Genes, Genomes, Genetics |date=October 2022 |volume=12 |issue=10 |doi=10.1093/g3journal/jkac220 |pmid=35997584 |pmc=9526052 }}</ref> <small>S.B. Johnson, Warén, Tunnicliffe, Van Dover, Wheat, Schultz & Vrijenhoek, 2014</small> * '''''Alviniconcha boucheti''''' - found in hydrothermal vents in the Manus, Fiji, and Lau basins ranging from {{cvt|1300|to|2700|m}} in depth. Hosts epsilon-proteobacterial endosymbionts. Named after deep sea gastropod scientist Philippe Bouchet. <small>S.B. Johnson, Warén, Tunnicliffe, Van Dover, Wheat, Schultz & Vrijenhoek, 2014</small> * '''''Alviniconcha hessleri''''' - first ''Alviniconcha'' species to be described. Found at hydrothermal vents in the Mariana Trough at depths greater than {{cvt|1400|m}}. Hosts gamma-proteobacterial endosymbionts. Most closely related to ''A. kojimai''. <small> Okutani & Ohta, 1988</small> * '''''Alviniconcha kojimai''''' - found at hydrothermal vents of the Manus, Fiji, and Lau Basins ranging from {{cvt|1480|to|2700|m}} in depth. Hosts both epsilon- and gamma-proteobacterial endosymbionts. <small>S.B. Johnson, Warén, Tunnicliffe, Van Dover, Wheat, Schultz & Vrijenhoek, 2014</small> * '''''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 {{cvt|2400|to|330|m}} in depth. Hosts epsilon-proteobacterial endosymbionts. <small>Okutani, 2014</small> * '''''Alviniconcha strummeri''''' - named after punk musician Joe Strummer of The Clash.<ref name=NPR>[https://www.npr.org/2014/12/20/372052995/a-snail-so-hardcore-its-named-after-a-punk-rocker A Snail So Hardcore It's Named After A Punk Rocker], at National Public Radio; published December 20, 2014; retrieved March 18, 2015</ref> Only found in the Southern Lau Basin, specifically at the Tui Mall vents sites at a depth of {{cvt|1850|m}}. Hosts both gamma- and epsilon- proteobacterial endosymbionts. <small>S.B. Johnson, Warén, Tunnicliffe, Van Dover, Wheat, Schultz & Vrijenhoek, 2014</small>
==References== {{Reflist}} * 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 == * {{Gastropods.com|key=9|id=16609|title=''Alviniconcha hessleri''|access-date=15 January 2019}}
{{Commons category}} {{Taxonbar|from=Q4738280}}
Category:Paskentanidae Category:Taxa described in 1988 Category:Animals living on hydrothermal vents Category:Taxa named by Takashi Okutani