Cremnoconchus

{{Short description|Genus of gastropods}}

{{Automatic taxobox

| image = Cremnoconchus syhadrensis.png

| image_caption = A drawing of Cremnoconchus syhadrensis

| taxon = Cremnoconchus

| authority = Blanford, 1869Blanford W. T. (1869). "Notes on some Indian and Mascarene Land-Shells". Annals and Magazine of Natural History (4)3: [https://archive.org/stream/s4annalsmagazine03londuoft#page/340/mode/2up 340]-344. [https://archive.org/stream/s4annalsmagazine03londuoft#page/342/mode/2up page 343].

| synonyms_ref = Bouchet, P.; Reid, David G. (2011). Cremnoconchus Blanford, 1869. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=446361 on 2011-09-05

| synonyms =

• Cremnobates Blanford, 1863Blanford W. T. (1863). "Descriptions of Cremnobates Syhadrensis and Lithotis rupicola, two new Generic Forms of Mollsca inhabiting Cliffs in the Western Ghats of India." Annals and Magazine of Natural History (3)12: [https://archive.org/stream/annalsmagazineof3121863lond#page/184/mode/2up 184]-187. [https://archive.org/stream/annalsmagazineof3121863lond#page/n501/mode/1up plate 4], figure 1-7.
• Cremnobates Swainson, 1855 (invalid homonym)
• Cremnobates Gunther, 1861 (invalid homonym)
• Lissoconchus Thiele, 1929

| diversity_ref =

| diversity = 9 freshwater species

}}

Cremnoconchus is a genus of small freshwater snails, gastropod mollusks in the otherwise marine family Littorinidae, the winkles or periwinkles.Strong E. E., Gargominy O., Ponder W. F. & Bouchet P. (2008). "Global Diversity of Gastropods (Gastropoda; Mollusca) in Freshwater". Hydrobiologia 595: 149-166. [http://hdl.handle.net/10088/7390 hdl.handle.net] {{doi|10.1007/s10750-007-9012-6}}.

The generic name Cremnoconchus is from the Greek word κρημνός which means precipice and from the Ancient Greek word κόγχος which means shell.

This is the only freshwater genus within the Littorinidae; all other genera belonging to the family are marine.{{Cite journal |last=Williams |first=S. T. |last2=Reid |first2=D. G. |last3=Littlewood |first3=D. T. J. |date=2003-07-01 |title=A molecular phylogeny of the Littorininae (Gastropoda: Littorinidae): unequal evolutionary rates, morphological parallelism, and biogeography of the Southern Ocean |url=https://www.sciencedirect.com/science/article/abs/pii/S1055790303000381 |journal=Molecular Phylogenetics and Evolution |volume=28 |issue=1 |pages=60–86 |doi=10.1016/S1055-7903(03)00038-1 |issn=1055-7903|url-access=subscription }} Molecular dating based on fossil records showed that Cremnoconchus separated from their last marine ancestor around 90 million years ago{{Cite journal |last=Saha |first=Anwesha |last2=Chakraborty |first2=Sudeshna |last3=Ravikanth |first3=G. |last4=Praveen Karanth |first4=K. |last5=Aravind |first5=N. A. |date=2022-09-01 |title=Endemicity and radiation in waterfalls of the Western Ghats: The genus Cremnoconchus (Gastropoda: Littorinidae) |url=https://www.sciencedirect.com/science/article/abs/pii/S1055790322001609 |journal=Molecular Phylogenetics and Evolution |volume=174 |pages=107547 |doi=10.1016/j.ympev.2022.107547 |issn=1055-7903|url-access=subscription }} and have since diversified within the Indian sub-continent. Based on this time of split, it has been postulated that either break-up of Gondwana or fluctuating sea levels might have facilitated their diversification. Based on the current distribution of the closest relatives of Cremnoconchus, a Gondwanan origin is highly likely.

[[File:Cremnoconchus map.png|left|thumb|Distribution map of three Cremnoconchus species:

style="background:violet; width:30px;" | | violet - Cremnoconchus conicus

style="background:green; width:30px;" | | green - Cremnoconchus carinatus

style="background:#8B0000; width:30px;" | | dark red - Cremnoconchus syhadrensis.

]]

The genus Cremnoconchus is endemic to the Western Ghats of India. All Cremnoconchus species live in spray zones of waterfalls i.e., not directly under the heavy flow of the water. Most species are restricted to one waterfall, earning them the title of point endemic. Very high footfall of tourists in the waterfalls of the Western ghats, accumulated waste, upstream pollution are all concerns for their habitat disturbance and degradation.{{Cite journal |last=Aravind |first=N. A. |last2=Sarma |first2=Roshmi Rekha |last3=Madhyastha |first3=N. A. |date=2016 |title=Conservation of Cremnoconchus Blanford 1869, an iconic freshwater gastropod genus from the Western Ghats, India |url=https://www.jstor.org/stable/24908513?seq=5 |journal=Current Science |volume=111 |issue=6 |pages=1097–1103 |issn=0011-3891}} These factors along with their extremely limited distribution make them highly vulnerable to extinction.