{{Short description|Genus of molluscs}} {{Automatic taxobox | image = Geloina expansa.jpg | image_alt = | image_caption = ''Geloina expansa'' | taxon = Geloina | authority = J. E. Gray, 1842 | type_species = Geloina coaxans | type_species_authority = J. F. Gmelin, 1791 }}
'''''Geloina''''' is a genus of bivalves in the family Cyrenoididae<ref>{{Cite web |title=WoRMS - World Register of Marine Species - Geloina J. E. Gray, 1842 |url=https://marinespecies.org/aphia.php?p=taxdetails&id=747106 |access-date=2026-04-14 |website=marinespecies.org |language=en}}</ref>.
''Geloina'' species are widely found in the Indo-Pacific region, specifically South East Asia. They are caught for culinary purposes, through both artisanal and commercial fisheries <ref name=":0">{{Cite journal |last1=Clemente |first1=Sandhya |last2=Ingole |first2=Baban |date=2011 |title=RECRUITMENT OF MUD CLAM Polymesoda erosa (SOLANDER, 1876) IN A MANGROVE HABITAT OF CHORAO ISLAND, GOA |journal=Brazilian Journal of Oceanography |volume=59 |issue=2 |pages=154 |doi=10.1590/S1679-87592011000200004 |s2cid=53469415 }}</ref>.
== Taxonomy == Previously a part of the Cyrenidae family due to morphological similarities, ''Geloina'' was transferred to Cyrenoididae in a research article published in the Invertebrate Systematics journal. The article reveals that ''Geloina'' species were more closely related to those in Cyrenoididae than Cyrenidae.<ref name=":4">{{Cite journal |last1=Wu |first1=Ruiwen |last2=Liu |first2=Lili |last3=Liu |first3=Xiongjun |last4=Ye |first4=Yingying |last5=Wu |first5=Xiaoping |last6=Xie |first6=Zhicai |last7=Liu |first7=Zhenyuan |last8=Li |first8=Zhengfei |date=2023-09-26 |editor-last=Giribet |editor-first=Gonzalo |title=Towards a systematic revision of the superfamily Cyrenoidea (Bivalvia: Imparidentia): species delimitation, multi-locus phylogeny and mitochondrial phylogenomics |url=https://connectsci.au/is/article/37/9/607/85863/Towards-a-systematic-revision-of-the-superfamily |journal=Invertebrate Systematics |language=en |volume=37 |issue=9 |pages=607–622 |doi=10.1071/IS23015 |issn=1445-5226|doi-access=free }}</ref>
Many of ''Geloina'' species previously belong to the genus Polymesoda. For the names of these species, see List of former species in the genus Polymesoda.
There has been disagreement about the validity and distinction of some ''Geloina'' species based on their external description. Research was done using species delimitation on barcoding data, revealing that there are multiple cryptic species within ''Geloina expansa.''<ref name=":4" />
=== Species ===
* ''Geloina bengalensis'' (Lamarck, 1818)
alt=Geloina bengalensis (MNHN-IM-2012-27662) 002|center|thumb|''Geloina bengalensis''
* ''Geloina bernardiana'' (Prime, 1861) * ''Geloina coaxans'' (Gmelin, 1791) * ''Geloina divaricata'' (Deshayes, 1855) * ''Geloina expansa'' (Mousson, 1849) * ''Geloina luchuana'' (Pilsbry, 1894) * ''Geloina mactraeformis'' (Prime, 1860) * ''Geloina moerchiana'' (Prime, 1866) * ''Geloina nitida'' (Deshayes, 1855)
alt=Geloina nitida (MNHN-IM-2000-32436)|center|thumb|''Geloina nitida''
* ''Geloina oviformis'' (Deshayes, 1854) * ''Geloina papua'' (R. P. Lesson, 1831) * ''Geloina schepmani'' M. Huber, 2015 * ''Geloina triangularis'' (Metcalfe, 1852) * ''Geloina vanikorensis'' (Quoy & Gaimard, 1835)
== Morphology == Like others in the family, ''Geloina'' species have olive-colored periostraca and distinct lateral teeth. The genus' distinct characteristic is its smooth lateral teeth. <ref>{{Cite book |url=https://www.biodiversitylibrary.org/page/55295773 |title=Synopsis of the contents of the British Museum |date=1842 |publisher=Woodfall and Son |edition=44 |volume= |location=London |language=en |doi=10.5962/bhl.title.144663 |archive-url=http://web.archive.org/web/20250622185842/https://www.biodiversitylibrary.org/page/55295773 |archive-date=2025-06-22}}</ref>
When young, ''Geloina'' species shells have a color mix of yellow and shades of green. This eventually darkens as they ages. Their length can vary due to different living habitats such salinity, pH level and sediment composition.<ref name=":1">{{Cite journal |last1=Ngo |first1=Thi Thu Thao |last2=Singano |first2=Atupele Ellen |date=December 2024 |title=Mangrove Clam Genus Geloina: A Comprehensive Review of Biology |url=https://www.researchgate.net/publication/388324076 |journal=Journal of Fisheries and Environment |volume=48 |issue=3 |pages=70 |via=ResearchGate}}</ref> ''Geloina expansa'' can measure more than 100mm in length.
''Geloina'' is dioecious and its sex can be determined by the visual and color of the gonads. <ref name=":1" />
== Behaviours & ecology == ''Geloina'' are brackish water clams. They lives semi-infaunal. They can be found burrowed deep in the soft sediments of tropical and sub-tropical mangrove swamps.<ref name=":2">{{Cite journal |last1=Ngo |first1=Thi Thu Thao |last2=Singano |first2=Atupele Ellen |date=December 2024 |title=Mangrove Clam Genus Geloina: A Comprehensive Review of Biology |url=https://www.researchgate.net/publication/388324076 |journal=Journal of Fisheries and Environment |volume=48 |issue=3 |pages=67 |via=ResearchGate}}</ref> Adults are mostly seen in the landward side and favor high-tide, while juveniles are mostly seen in the seaward side and favor low-tide and mid-tide.<ref name=":3">{{Cite journal |last1=Clemente |first1=Sandhya |last2=Ingole |first2=Baban |date=2011 |title=RECRUITMENT OF MUD CLAM Polymesoda erosa (SOLANDER, 1876) IN A MANGROVE HABITAT OF CHORAO ISLAND, GOA |journal=Brazilian Journal of Oceanography |volume=59 |issue=2 |pages=159 |doi=10.1590/S1679-87592011000200004 |s2cid=53469415 }}</ref>
''Geloina'' species are filter-feeders. They use a specialized siphon system to draw in water, filtering out plankton, algae, and organic particles through their gills while expelling cleaned water. Research has been done on the topic of using ''Geloina expansa'' as a method for monitoring heavy metal pollution in water sources.<ref name=":1" />
== References == {{Reflist|30em}}
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Category:Cyrenoididae Category:Bivalve genera