''Juga'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

freshwater snail Freshwater snails are gastropod mollusks which live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs ...

s with a

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

and an operculum, aquatic

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

s in the family

Semisulcospiridae Semisulcospiridae, common name semisulcospirids, is a family of freshwater snails, aquatic gilled gastropod mollusks with an operculum, in the superfamily Cerithioidea. MolluscaBase eds. (2021). MolluscaBase. Semisulcospiridae J. P. E. Morri ...

. These snails are native to the rivers of the northwestern United States and adjacent

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

. Several species are

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to isolated large springs in the American Great Basin.Strong, E. E., & Whelan, N. V. (2019). Assessing the diversity of western North American Juga (Semisulcospiridae, Gastropoda). Molecular Phylogenetics and Evolution, 136, 87-103. The most abundant and widespread species, ''Juga plicifera'', attains a height of up to 35 mm. It is sculpted with fine spiral ridges and variably developed ribs that frequently disappear in parts of the shell made as the animal matures.

Species

The following species and subspecies are recognized: Subgenus ''Juga'' s.s. * '' Juga hemphilli'' (J. Henderson, 1935) ** ''Juga hemphilli dallesensis'' (J. Henderson, 1935) ** ''Juga hemphilli maupinensis'' (J. Henderson, 1935) * '' Juga plicifera'' (I. Lea, 1838) * '' Juga silicula'' (Gould, 1847) Subgenus '' Calibasis'' * '' Juga acutifilosa'' (Stearns, 1890) ** ''Juga acutifilosa pittensis'' ** ''Juga acutifilosa siskiyouensis'' * '' Juga occata'' (Hinds, 1844) Subgenus '' Oreobasis'' * '' Juga bulbosa'' (Gould, 1847) * '' Juga interioris'' (Goodrich, 1944) * '' Juga laurae'' (Goodrich, 1944) * ''

Juga nigrina ''Juga'' is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Semisulcospiridae. These snails are native to the rivers of the northwestern United States and adjacent British Columbia. Several ...

'' (I. Lea, 1856) subgenus ? * ''

Juga chacei ''Juga'' is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Semisulcospiridae. These snails are native to the rivers of the northwestern United States and adjacent British Columbia. Several ...

'' (Henderson, 1935)NatureServe
Explorer, accessed 19 November 2015. * ''

Juga newberryi ''Juga'' is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Semisulcospiridae. These snails are native to the rivers of the northwestern United States and adjacent British Columbia. Several ...

'' (I. Lea, 1860) * '' Juga orickensis'' (Henderson, 1935)

Ecology

Parasites of ''Juga'' spp. include the bacterium ''

Neorickettsia risticii ''Neorickettsia risticii'', formerly ''Ehrlichia risticii,'' is an obligate intracellular gram negative bacteria that typically lives as an endosymbiont to parasitic flatworms, specifically flukes. ''N. risticii'' is the known causative agent of ...

'', which causes

Potomac horse fever Potomac Horse Fever (PHF) is a potentially-fatal febrile illness affecting horses caused by the intracellular bacterium '' Neorickettsia risticii''. PHF is also known as Shasta River Crud and Equine Monocytic Ehrlichiosis. It was first described i ...

along with the associated

trematode Trematoda is a class of flatworms known as flukes. They are obligate internal parasites with a complex life cycle requiring at least two hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive host ...

vector.. ''Juga'' species are also infected with the bacterium ''

Neorickettsia helminthoeca ''Neorickettsia helminthoeca'' is a bacterium in the ''Neorickettsia'' genus that causes Salmon poisoning disease. Salmon poisoning disease Salmon poisoning disease (SPD) is a fatal disease of dogs and other canids caused by a rickettsial bacter ...

'' and its associated fluke, ''

Nanophyetus salmincola ''Nanophyetus salmincola'' is a food-borne intestinal trematode parasite prevalent on the Pacific Northwest coast. The species may be the most common trematode endemic to the United States. The life cycle of the ''N. salmincola'' requires thr ...

''Greiman, S. E., Kent, M. L., Betts, J., Cochell, D., Sigler, T., & Tkach, V. V. (2016). Nanophyetus salmincola, vector of the salmon poisoning disease agent Neorickettsia helminthoeca, harbors a second pathogenic Neorickettsia species. Veterinary parasitology, 229, 107-109.

References

* Clarke, Arthur H. 1981. The freshwater mollusks of Canada. National Museums of Canada. 446 pp. * List including species in Oregon: https://web.archive.org/web/20081008065745/http://oregonstate.edu/ornhic/data/2004/inverts.html

External links

{{Taxonbar, from=Q3169473 Semisulcospiridae