View source for Hygrobia

{{Short description|Genus of beetles}}
{{Italic title}}
{{Automatic_taxobox
| image = Hygrobia hermanni HabitusDors.jpg
| image_caption = ''Hygrobia hermanni''
| taxon = Hygrobia
| authority = [[Latreille]], 1804
| subdivision_ranks = Species
| subdivision = *''[[Hygrobia australasiae]]'' <small>(Clark, 1862)</small>
*''[[Hygrobia davidi]]'' <small>Bedel, 1883</small>
*''[[Hygrobia hermanni]]'' <small>(Fabricius, 1775)</small>
*''[[Hygrobia maculata]]'' <small>Britton, 1981</small>
*''[[Hygrobia nigra]]'' <small>(Clark, 1862)</small>
*''[[Hygrobia wattsi]]'' <small>Hendrich, 2001</small>
}}
'''''Hygrobia''''' is a [[genus]] of aquatic [[beetle]]s native to [[Europe]], [[North Africa]], [[China]] and [[Australia]]. It is the only genus in the [[Family (biology)|family]] '''Hygrobiidae''', also known as the '''Paelobiidae'''.<ref name=":1">{{Cite journal|last=Nilsson|first=A. N.|date=2006|title=Which name is valid – Hygrobiidae or Paelobiidae?|url=http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-7453|journal=Latissimus|volume=21|pages=37–39}}</ref> These are known commonly as '''squeak beetles'''<ref>Michat, M. C., et al. (2014). [http://www.mapress.com/zootaxa/2014/f/z03827p330f.pdf Description of the third instar of ''Hygrobia nigra'' (Clark, 1862) (Coleoptera: Paelobiidae), with a key for the identification of mature larvae of ''Hygrobia'' Latreille, 1804 and phylogenetic analysis.] ''Zootaxa'' 3827(3) 318-30.</ref> or '''screech-beetles'''.<ref>Watson, L. and M. J. Dallwitz. [http://delta-intkey.com/britin/wat/www/hygrobia.htm ''Hygrobia''.] British Insects: The Families of Coleoptera.</ref>
There are six known living [[species]], with a highly disjunct distribution, and one extinct species, ''Hygrobia cretzschmari''.
== Biology ==
All species occur in lowland areas <ref name=":0">Dettner, K. (2005). Noteridae. ''Handbook of Zoology'', ''4'', 72–90.</ref> and are mainly found in stagnant water.<ref name=":2">Holmen, M. (1987). Family Hygrobiidae. ''The aquatic Adephaga (Coleoptera) of Fennoscandia and Denmark''. Brill, 136–142.</ref> They live in the mud, silt, and detritus of ponds.<ref name=":0" />
None of the species occur in [[sympatry]], except for ''H. nigra'' and ''H. australasiae'' in south-eastern Australia.<ref name=":3">Hawlitschek, O., Hendrich, L., & Balke, M. (2012). Molecular phylogeny of the squeak beetles, a family with disjunct Palearctic-Australian range. ''Molecular Phylogenetics and Evolution'', ''62''(1), 550–554.</ref>
Both adults and larvae are [[predator]]s, specialized on [[Oligochaeta|oligochaete]] worms. The adults feed for as long as 30 min, coming to the surface very briefly to renew the air-supply.<ref>Balfour‐Browne, F. (1922, April). 5. The Life‐History of the Water‐Beetle Pelobius tardus Herbst. In ''Proceedings of the Zoological Society of London'' (Vol. 92, No. 1, pp. 79–97). Blackwell Publishing Ltd.</ref>
Adults are able to [[Stridulation|stridulate]], producing an audible sound,<ref>Jäch, M. (1995).     Hygrobiidae (Coleoptera). In: Jäch, M.A., Ji, L. (Eds.), Water Beetles of China,     vol. I. Zoologisch-Botanische Gesellschaft in Österreich und Wiener Coleopterologenverein,     Wien, pp. 109–110.</ref> which is why they are called squeak or screech beetles.
== Morphology ==
The body length ranges from 8.0 to 11.0&nbsp;mm. [[Compound eyes]] are present, not divided into ventral and dorsal portions, strongly protruding. [[Labrum (arthropod mouthpart)|Labrum]] is short and transverse. The [[Antenna (biology)|antennae]] are filiform, almost glabrous, with 11 segments.<ref name=":2" />
== Phylogeny and evolution ==
The [[monophyly]] of the family is not in doubt.<ref name=":3" />
Hygrobiidae is thought to be the [[sister group]] to a clade comprising [[Dytiscidae]] (diving beetles), [[Amphizoidae]] (trout stream beetles) and [[Aspidytidae]] (cliff beetles), based on [[DNA]] sequence data.<ref name=":3" /><ref>Balke, M., Ribera, I., & Beutel, R. G. (2005). The systematic position of Aspidytidae, the diversification of Dytiscoidea (Coleoptera, Adephaga) and the phylogenetic signal of third codon positions. ''Journal of Zoological Systematics and Evolutionary Research'', ''43''(3), 223–242.</ref><ref>Balke, M., Ribera, I., Beutel, R., Viloria, A., Garcia, M., & Vogler, A. P. (2008). Systematic placement of the recently discovered beetle family Meruidae (Coleoptera: Dytiscoidea) based on molecular data. ''Zoologica Scripta'', ''37''(6), 647–650.</ref>
Regarding the relationships among the species of ''Hygrobia'', a recent phylogenetic analysis suggested a sister group relationship between ''H. hermanni'' and a clade formed by the Australian species, with ''H. nigra'' sister to ''H. australasiae.''<ref name=":3" />
Hygrobiidae probably diverged from other Hydradephagan clades around the time of the initial breakup of [[Pangaea|Pangea]]. The split between today's [[Palearctic realm|Palearctic]] and Australian clades occurred later, possibly in the middle [[Mesozoic]], by dispersal events.<ref name=":3" />
== Species diversity and distribution ==
''Hygrobia australasiae'' (Clark, 1862) - Australia
''Hygrobia davidi'' Bedel, 1883 - [[Jiangxi]], southeastern China
''Hygrobia hermanni'' (Fabricius, 1775) - Europe, northern Africa ([[Morocco]], [[Algeria]] and [[Tunisia]]), and [[Israel]]
''Hygrobia maculata'' Britton, 1981 - Australia
''Hygrobia nigra'' (Clark, 1862) - Australia
''Hygrobia wattsi'' Hendrich, 2001 - Australia
== Family name ==
There has been a controversy associated with deciding which is the valid family name of squeak beetles: Hygrobiidae or Paelobiidae.<ref name=":1" /> Paelobiidae has priority over Hygrobiidae, but the latter name was until recently much more widely used.<ref>Lawrence, J. F., & Newton, A. F. (1995). Families and subfamilies of Coleoptera with selected genera, notes, references and data on family-group names.[pp. 779-1006].[in:] Biology, Phylogeny and Classification of Coleoptera. Papers celebrating the 80th birthday of Prof. Roy A. ''Museum i Instyut Zoologii PAN, Warzawa''.</ref>
==References==
{{Reflist}}
==External links==
{{Commons}}
{{Wikispecies}}
*[https://web.archive.org/web/20110604041358/http://www.faunaeur.org/full_results.php?id=120370 ''Hygrobia''.] Fauna Europaea.
{{Coleoptera|2}}
{{Taxonbar|from=Q15635851}}
[[Category:Adephaga genera]]
[[Category:Palearctic insects]]
[[Category:Insects of Australia]]