For the municipality in Finland, see Juuka

Juuka

Juuka is a municipality of Finland.It is located in the province of Eastern Finland and is part of the North Karelia region. The municipality has a population of and covers an area of of which is water. The population density is ....

Juga is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of freshwater snail

Freshwater snail

A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....

s with a gill

Gill

A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...

 and an operculum

Operculum (gastropod)

The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

, aquatic

Aquatic animal

An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...

 gastropod mollusks in the family Semisulcospiridae

Semisulcospiridae

Semisulcospiridae, common name semisulcospirids, is a family of freshwater snails, aquatic gilled gastropod mollusks with an operculum, in the superfamily Cerithioidea....

.

These snails are native to the rivers of the northwestern United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 and adjacent British Columbia

British Columbia

British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

. Several species are endemic to isolated large springs

Spring (hydrosphere)

A spring—also known as a rising or resurgence—is a component of the hydrosphere. Specifically, it is any natural situation where water flows to the surface of the earth from underground...

 in the American Great Basin.

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 pecies and subspecies are listed by Burch

John B. Burch

John Bayard Burch is an American zoologist, a biology professor at the University of Michigan, and is the Curator of Mollusks at the University of Michigan Museum of Zoology. His research interests are broad, and have encompassed not only the anatomy, systematics, and genetics of mollusks, but...

 (1982):

Subgenus Juga s.s.

• Juga hemphilli
  • Juga hemphilli dallensis
• Juga plicifera
• Juga silicula

Subgenus Calibasis

• Juga acutifilosa
  • Juga acutifilosa pittensis
  • Juga acutifilosa siskiyouensis
• Juga occata

Subgenus Oreobasis

• Juga bulbosa
• Juga interioris
• Juga laurae
• Juga nigrina

Ecology

Parasite of Juga spp. include bacterium Neorickettsia risticii that causes Potomac horse fever

Potomac Horse Fever

Potomac Horse Fever 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...

 and the associated trematode vector.