Editing Spercheus

{{Short description|Genus of beetles}}
{{for|the Greek river|Spercheios}}
{{automatic taxobox
|taxon=Spercheus
| display_parents = 3
|authority = [[Johann Gottlieb Kugelann|Kugelann]], 1798
|parent_authority =Erichson, 1837
| image= Spercheus senegalensis Laporte de Castelnau, 1832 (9537687977).png
| image_caption =Dorsal view of ''S. senegalensis''
| image2=Spercheus senegalensis Laporte de Castelnau 1832 (9537678637).png
| image2_caption =Profile view of ''S. senegalensis''
}}

'''''Spercheus''''' is a genus of aquatic beetles which are placed in a family of their own, '''Spercheidae''' within the [[Hydrophiloidea]]. About 20 species are known from around the world except the [[Nearctic realm|Nearctic]]<ref name=":0" /> with the majority being from the [[Oriental realm|Oriental]] and [[Afrotropical realm|Afrotropical]] Realms.
[[File:De_metamorphosi_eleutheratorum_observationes_(Tab._IX)_(8243601573).jpg|thumb|right|Larva of ''Spercheus emarginatus'']]
All life stages are found in shallow still water with rich vegetation, which in some species includes temporary saline pools.<ref>"12. Hydrophiloidea Latreille, 1802". ''Volume 1 Coleoptera, Beetles. Morphology and Systematics'', edited by Rolf G. Beutel and Richard A.B. Leschen, Berlin, Boston: De Gruyter, 2016, pp. 231–272.</ref> Adults and larvae live attached to pieces of vegetation or debris, and also walk on the underside of the water surface. Air is held in a bubble on the underside of the body. The larvae feed on grazed detritus as well as drifting algae, dead organisms, and other organic refuse. The adults live as [[filter feeder]]s on floating debris like decaying plant material and other decomposing organic remains.<ref name=":0" /> The adult females build a silken-egg case which they attach to their mid-tibiae and held by the hind legs, carried below the abdomen.<ref>{{cite journal|doi=10.1076/snfe.36.3.199.2128|title=A new Neotropical species of ''Spercheus'' Kugelann, and its larval stages (Coleoptera, Hydrophiloidea: Spercheidae)|year=2001|last1=Archangelsky|first1=Miguel|journal=Studies on Neotropical Fauna and Environment|volume=36|issue=3|pages=199–204|s2cid=84693791|hdl=11336/97451|hdl-access=free}}</ref> These beetles were formerly placed in the family [[Hydrophilidae]] but are distinctive.<ref>{{cite journal|doi=10.1046/j.1365-3113.1998.00039.x|title=Phylogeny of Hydrophiloidea (Coleoptera: Staphyliniformia) using characters from adult and preimaginal stages|year=1998|last1=Archangelsky|first1=Miguel|journal=Systematic Entomology|volume=23|pages=9–24|s2cid=83521707}}</ref>

The front of the head is notched and the 7–9 segmented antenna has the terminal 3–4 segments club like and an enlarged fourth segment. The elytra are very convex and one or two abdominal segments may extend beyond the apex. They have 5 tarsal segments on all legs.<ref>{{cite journal| author1=Short, A. E. Z.| author2= Fikáček| year=2013| title= Molecular phylogeny, evolution and classification of the Hydrophilidae (Coleoptera) | journal= Systematic Entomology|volume= 38| issue=4| pages= 723–752|doi=10.1111/syen.12024 | s2cid= 83050858}}</ref><ref name=":0">{{cite book |title=Australian Beetles Volume 2: Archostemata, Myxophaga, Adephaga, Polyphaga (part) |publisher=CSIRO |year=2019 |editor1=Slipinski, Adam |chapter=19. Spercheidae Erichson, 1837 |editor2=Lawrence, John}}</ref>

Possible fossils of ''Spercheus'' have been described from the [[Eocene]] aged [[Bembridge Marls]] of the Isle of Wight, England.<ref name=":0" /> The extinct genus ''[[Prospercheus]]'' from the Late [[Jurassic]] of [[Ulan Malgait Formation|Shar-Teg]], Mongolia, has also been considered a close relative of ''Spercheus'', and also placed in Spercheidae.<ref>{{Cite journal |last1=Toussaint |first1=Emmanuel F. A. |last2=Seidel |first2=Matthias |last3=Arriaga-Varela |first3=Emmanuel |last4=Hájek |first4=Jiří |last5=Král |first5=David |last6=Sekerka |first6=Lukaš |last7=Short |first7=Andrew E. Z. |last8=Fikáček |first8=Martin |date=January 2017 |title=The peril of dating beetles |journal=Systematic Entomology |language=en |volume=42 |issue=1 |pages=1–10 |doi=10.1111/syen.12198 |issn=0307-6970|doi-access=free }}</ref><ref>{{Cite journal |last=Prokin |first=A. A. |date=October 2009 |title=New water scavenger beetles (Coleoptera: Hydrophilidae) from the mesozoic of Mongolia |url=http://link.springer.com/10.1134/S0031030109060094 |journal=Paleontological Journal |language=en |volume=43 |issue=6 |pages=660–663 |doi=10.1134/S0031030109060094 |s2cid=129299140 |issn=0031-0301}}</ref>

== Species ==
* ''Spercheus belli'' {{small|Champion, 1919}}
* ''Spercheus burgeoni'' {{small|Orchymont, 1929}}
* ''Spercheus cerisyi'' {{small|Guérin Méneville, 1842}}
* ''Spercheus crenulatus'' {{small|Fairmaire, 1893}}
* ''Spercheus emarginatus'' {{small|(Schaller, 1783)}}
* ''Spercheus fimbriicollis'' {{small|Bruch, 1915}}
* ''Spercheus gerardi'' {{small|Orchymont, 1929}}
* ''Spercheus halophilus'' {{small|Archangelsky, 2001}}
* ''Spercheus hanseni'' {{small|Hebauer, 1990}}
* ''Spercheus hovanus'' {{small|Fairmaire, 1903}}
* ''Spercheus humeralis'' {{small|Régimbart, 1906}}
* ''Spercheus platycephalus'' {{small|MacLeay, 1825}}
* ''Spercheus senegalensis'' {{small|Castelnau, 1832}}
* ''Spercheus siamensis'' {{small|Hebauer, 1990}}
* ''Spercheus spangleri'' {{small|Hebauer, 1990}}
* ''Spercheus stangli'' {{small|Schwarz & Barber, 1918}}
* ''Spercheus stasimus'' {{small|Orchymont, 1937}}
* ''Spercheus wattsi'' {{small|Hebauer, 1999}}

==References ==
{{reflist}}

==External links ==
* [https://www.mdfrc.org.au/bugguide/display.asp?type=5&class=17&subclass=&Order=1&family=243&couplet=0 Australian Freshwater Invertebrates]
* [http://tolweb.org/Spercheus/9214 Tree of Life]
{{Coleoptera|4}}
{{taxonbar|from=Q18113956|from2=Q755568 }}

[[Category:Hydrophiloidea]]
[[Category:Polyphaga genera]]