Georissus, also called minute mud-loving beetles, is the only genus in the beetle family Georissidae (or Georyssidae). They are tiny insects living in wet soil, often near water. They are found on every continent except Antarctica.
| Georissus | |
|---|---|
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| |
| G. crenulatus | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Infraorder: | Staphyliniformia |
| Superfamily: | Hydrophiloidea |
| Family: | Georissidae Laporte, 1840[1] |
| Genus: | Georissus Latreille, 1809 |
| Species | |
|
see text | |
| Synonyms | |
|
Georyssus Stephens, 1828 (Unjustified Emendation) | |
Characteristics
editGeorissidae are small beetles (length 1–2 mm). They have a broadly oval body whose outline is more or less interrupted between the pronotum and the elytra. The head and pronotum are granulate, the prosternum is rudimentary, without intercoxal processes. The anterior coxae and trochanters are fused. The basal ventrite is very large.[2]
Ecology
editSpecies are generally found within mud and sand at the periphery of rivers and streams, but also occur in tropical rainforest leaf litter. Species of Georissus are predators on invertebrates, and under laboratory conditions sometimes engage in cannibalism.[3] Species within the genus are known for their habit of psammophory (actively covering their elytra with sand or mud) which helps protect them against predators.[4]
Systematics and evolution
editThere are about 75 living species, including:
- Georissus australis
- Georissus babai
- Georissus bipartitus
- Georissus caelatus
- Georissus californicus
- Georissus canalifer
- Georissus capitatus
- Georissus coelosternus
- Georissus costatus
- Georissus crenulatus
- Georissus formosanus
- Georissus fusicornis
- Georissus granulosus
- Georissus instabilis
- Georissus japonicus
- Georissus kingii
- Georissus kurosawai
- Georissus laesicollis
- Georissus minusculus
- Georissus occidentalis
- Georissus pusillus
- Georissus sakaii
- Georissus septemcostatus
- Georissus substriatus
- Georissus trifossulatus
The genus is divided into three subgenera (Georissus, Neogeorissus and Nipponogeorissus). Formerly it was included within the family Hydrophilidae. Recent molecular data indicate, that they belong to a clade comprising the small groups of Hydrophiloidea - Epimetopidae, Hydrochidae, Helophoridae and Georissidae.[5]
References
edit- ^ Bouchard, Patrice; Bousquet, Yves; Davies, Anthony E.; Alonso-Zarazaga, Miguel A.; Lawrence, John F.; Lyal, Chris H. C.; Newton, Alfred F.; Reid, Chris A. M.; Schmitt, Michael; Ślipiński, S. Adam; Smith, Andrew B. T. (2011). "Family-group names in Coleoptera (Insecta)". ZooKeys (88): 1–972. Bibcode:2011ZooK...88....1B. doi:10.3897/zookeys.88.807. PMC 3088472. PMID 21594053.
- ^ M.Hansen. Phylogeny and classification of the staphyliniform beetle families (Coleoptera). Biologiske Skrifter 48, Copenhagen, 1997
- ^ "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.
- ^ Bameul, Franck (January 1989). "Description of the camouflage behaviour of a Coleoptera: The active disguise of Georissus crenulatus (Coleoptera Georissidae), and proposal of a new classification of disguises among invertebrates". Comptes rendus de l'Académie des Sciences (in French). 309: 351–356.
- ^ D.Bernhard et al., From terrestrial to aquatic habitats and back again — molecular insights into the evolution and phylogeny of Hydrophiloidea (Coleoptera) using multigene analyses. Zoologica Scripta 35 (6), 597–606, 2006