Water-penny beetles are a family (the Psephenidae) of 272 species (in 35 genera) of aquatic beetles found on all continents except Antarctica, in both tropical and temperate areas.[2] The young, which live in water, resemble tiny pennies. The larvae feed – usually nocturnally – on algae on rock surfaces.[3] The presence of water-penny larvae in a stream can be used as a test for the quality of the water, as they are pollution-sensitive.[4] They cannot live in habitats where rocks acquire a thick layer of algae, fungi, or inorganic sediment. Therefore, their presence along with other diverse phyla signifies good-quality water. They are around 6 to 10 millimeters in length.[5]
A water-penny larva's shell is oval-shaped to almost circular and is commonly a copper color, hence the name, 'water-penny'. Water-pennies obtain oxygen through their membrane and through feathery gills located at the base of the abdomen. They are typically found in riffles in streams with a moderate to fast current, clinging to the underside of logs or rocks. Occasionally, they can be found on rocks along the shores of lakes. Attached to the legs are scrapers, which are used to scrape the algae from the surface of a log or rock.
In North America, they are usually found in the Northeast, and occasionally discovered in the Southwest. Some genera in the US:[6]
Psephenus: the Northeast and the west coast (from Oregon to California; usually below 4,000 feet elevation in California).
Eubrianax: California, up to 6,000 feet elevation.
^Beutel, Rolf G. & Leschen, Richard (2005). Morphology and Systematics. Vol. 1. Walter de Gruyter. p. 521. ISBN978-3-11-090455-0.
^ abEvans, Arthur V. (2014). Beetles of Eastern North America. Princeton University Press. p. 203. ISBN978-1-4008-5182-9.
^: The pollution sensitivity categories for benthic macroinvertebrates: sensitive, somewhat-sensitive, and tolerant. Water-pennies belong to the sensitive category.
^Arnett, Ross H. & Thomas, Michael C. (2002). American Beetles: Polyphaga: Scarabaeoidea through Curculionoidea, Volume 2. Pages 133-134.
Wikimedia Commons has media related to Psephenidae.
Murray, Tom (January 12, 2015). "Family Psephenidae - Water Penny Beetles". BugGuide. Retrieved July 7, 2020.
Video of a water-penny from Thailand
April 12, 2024
water, penny, beetle, family, psephenidae, species, genera, aquatic, beetles, found, continents, except, antarctica, both, tropical, temperate, areas, young, which, live, water, resemble, tiny, pennies, larvae, feed, usually, nocturnally, algae, rock, surfaces. Water penny beetles are a family the Psephenidae of 272 species in 35 genera of aquatic beetles found on all continents except Antarctica in both tropical and temperate areas 2 The young which live in water resemble tiny pennies The larvae feed usually nocturnally on algae on rock surfaces 3 The presence of water penny larvae in a stream can be used as a test for the quality of the water as they are pollution sensitive 4 They cannot live in habitats where rocks acquire a thick layer of algae fungi or inorganic sediment Therefore their presence along with other diverse phyla signifies good quality water They are around 6 to 10 millimeters in length 5 Water penny beetleTemporal range Cenomanian Recent PreꞒ Ꞓ O S D C P T J K Pg NLarvaScientific classificationDomain EukaryotaKingdom AnimaliaPhylum ArthropodaClass InsectaOrder ColeopteraSuborder PolyphagaInfraorder ElateriformiaSuperfamily ByrrhoideaFamily PsephenidaeLacordaire 1854 1 SubfamiliesEubrianacinae Jacobson 1913Eubriinae Lacordaire 1857Psepheninae Lacordaire 1854Psephenoidinae Hinton 1939Eubria palustris adultA water penny larva s shell is oval shaped to almost circular and is commonly a copper color hence the name water penny Water pennies obtain oxygen through their membrane and through feathery gills located at the base of the abdomen They are typically found in riffles in streams with a moderate to fast current clinging to the underside of logs or rocks Occasionally they can be found on rocks along the shores of lakes Attached to the legs are scrapers which are used to scrape the algae from the surface of a log or rock In North America they are usually found in the Northeast and occasionally discovered in the Southwest Some genera in the US 6 Psephenus the Northeast and the west coast from Oregon to California usually below 4 000 feet elevation in California Eubrianax California up to 6 000 feet elevation Ectopria the northeastern and Central U S Acneus California and Oregon up to 4 000 feet As adults water pennies become terrestrial Adults are relatively short lived and eat little to nothing 3 Fossil genera editSubfamily Eubrianacinae Jacobson 1913 Succinumanax Bao et al 2018 Burmese amber Myanmar Cenomanian Vetujinbrianax Cai and Huang 2018 Burmese amber Myanmar Cenomanian Protacnaeus Wickham 1914 Florissant Formation Colorado Eocene Psephenella Martins Neto 1998 Tremembe Formation Brazil OligoceneReferences edit Psephenidae Integrated Taxonomic Information System Beutel Rolf G amp Leschen Richard 2005 Morphology and Systematics Vol 1 Walter de Gruyter p 521 ISBN 978 3 11 090455 0 a b Evans Arthur V 2014 Beetles of Eastern North America Princeton University Press p 203 ISBN 978 1 4008 5182 9 EPA The pollution sensitivity categories for benthic macroinvertebrates sensitive somewhat sensitive and tolerant Water pennies belong to the sensitive category Arnett Ross H amp Thomas Michael C 2002 American Beetles Polyphaga Scarabaeoidea through Curculionoidea Volume 2 Pages 133 134 Usinger Robert L 1956 Aquatic Insects of California p 365 External links edit nbsp Wikimedia Commons has media related to Psephenidae Murray Tom January 12 2015 Family Psephenidae Water Penny Beetles BugGuide Retrieved July 7 2020 Video of a water penny from Thailand Retrieved from https en wikipedia org w index php title Water penny beetle amp oldid 1169924391, wikipedia, wiki, book, books, library,
