Allocrangonyx

{{Short description|Genus of crustaceans}}

{{Automatic taxobox

| image = Allocrangonyxpelucidus2.jpg

| parent_authority = Holsinger, 1989 {{ITIS |id=609985 |taxon=Allocrangonyctidae Holsinger, 1989 }}

| taxon = Allocrangonyx

| authority = Schellenberg, 1936 {{ITIS |id=95099 |taxon=Allocrangonyx Schellenberg, 1936 }}

| subdivision_ranks = Species

| subdivision = *{{nowrap|Allocrangonyx pellucidus (Mackin, 1935)}}

  • Allocrangonyx hubrichti Holsinger, 1971

}}

File:Allocrangonyxpelluciduscropped.jpg

Allocrangonyx is a genus of troglobitic amphipod crustaceans from the South Central United States.{{cite journal |author=John R. Holsinger |year=1971 |title=A new species of the subterranean amphipod genus Allocrangonyx (Gammaridae), with a redescription of the genus and remarks on its zoogeography |journal=International Journal of Speleology |volume=3 |issue=3/4 |pages=317–331 |doi=10.5038/1827-806x.3.3.11 |doi-access=free |bibcode=1971IJSpe...3..317H }} The two species are both listed as vulnerable on the IUCN Red List.{{Cite iucn | author = Inland Water Crustacean Specialist Group | title = Allocrangonyx hubrichti | year = 1996 | page = e.T873A13087606 | doi = 10.2305/IUCN.UK.1996.RLTS.T873A13087606.en }}{{Cite iucn | author = Inland Water Crustacean Specialist Group | title = Allocrangonyx pellucidus | year = 1996 | page = e.T874A13087705 | doi = 10.2305/IUCN.UK.1996.RLTS.T874A13087705.en }} The animals are blind and unpigmented. During the male's development, the outer ramus of the third uropod differentiates into secondary segments and grows to a length greater than the animal's body length.

File:Turner falls ok.jpg.]]

''Allocrangonyx pellucidus''

A. pellucidus, the "Oklahoma cave amphipod", is known from caves and springs in the Arbuckle Mountains of Johnston, Murray and Pontotoc counties, Oklahoma.{{cite journal |title=Annotated checklist of the amphipod crustaceans of Oklahoma, with emphasis on groundwater habitats |author1=G. O. Graening |author2=John R. Holsinger |author3=Danté B. Fenolio |author4=Elizabeth A. Bergey |author5=Caryn C. Vaughn |journal=Proceedings of the Oklahoma Academy of Science |volume=86 |pages=65–74 |year=2006 |url=http://www.anotheca.com/Oklahoma_amphipods.pdf }} The largest males reach {{convert|21.75|mm|abbr=on}} long, while females reach {{convert|18|mm|abbr=on}}.

''Allocrangonyx hubrichti''

A. hubrichti, the "Central Missouri cave amphipod" or "Hubricht's long-tailed amphipod",{{cite web |title=Conservation assessment for Hubricht's long-tailed amphipod (Allocrangonyx hubrichti) |author =Julian J. Lewis |publisher=USDA Forest Service |date=October 2002 |url=http://www.fs.fed.us/r9/wildlife/tes/ca-overview/docs/invertebrate_allocrangonyx_hubrichti-Hubrichts%20Amphipod.pdf }} was thought for many years to be endemic to the state of Missouri, but specimens were discovered in 1996, {{convert|283|km|abbr=on}} away, in a water well near Romance, White County, Arkansas.{{cite journal |author1=Henry W. Robison |author2=John R. Holsinger |title=First record of the subterranean amphipod crustacean Allocrangonyx hubrichti (Allocrangonyctidae) in Arkansas |journal=Journal of the Arkansas Academy of Science |volume=54 |year=2000 |pages=153 |url=http://libinfo.uark.edu/aas/issues/2000v54/v54a27.pdf }} While the well is drilled into Pennsylvanian age sandstone, all previous records have been from Ordovician limestones and dolomites.{{clear left}}

References