The Trinity bristle snail (''Monadenia setosa'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of medium-sized

land snail A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial molluscs, terrestrial gastropod mollusks that have gastropod shell, shel ...

, a

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...

pulmonate Pulmonata or pulmonates is an informal group (previously an order, and before that, a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group inclu ...

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

in the family Monadeniidae.

Description

The Trinity bristle snail attains a body length of approximately 2.5 cm. It is brown or chestnut-colored and covered with minuscule, translucent bristles, which give the species its common name.

Distribution and habitat

This species is

endemic Endemism is the state of a species being found only 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 foun ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

. This snail is found in northwestern Trinity County, along the Trinity River, up some of its tributaries and into the Corral Bottom area. It has a healthy population within its territory. It likes cool, wet, shady

riparian A riparian zone or riparian area is the interface between land and a river or stream. In some regions, the terms riparian woodland, riparian forest, riparian buffer zone, riparian corridor, and riparian strip are used to characterize a ripar ...

zones, and prefers areas with a deciduous understory.

Ecology

The Trinity bristle snail is dependent on cool, moist conditions, and therefore it is only active at night. It spends warmer parts of the day stuck to shady areas on tree trunks, and in especially warm parts of the summer it may not move for days. When conditions are cool enough it feeds on

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

and the tender parts of green plants. The snail has a lifespan of over ten years, and may not reach full size for nearly that long. It is subject to predation by beetles and possibly rodents.

Survival threats

The species appears dependent on riparian habitats, and especially likes bigleaf maples (Acer macrophyllum), eating the leaves that are decomposing at the base of the trees (from observations during field work by Forest Service employee Gay Berrien who was involved with locating the snails during initial research in 1980). There have been no studies that show it ever occupied a larger area than it does now—much of the northwestern portion of Trinity County. At the edges of its territory it has been known to cross with others of the Monadenia genus

References

External links

{{Taxonbar, from=Q3075749 Monadenia

Snail A snail is a shelled gastropod. The name is most often applied to land snails, terrestrial molluscs, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gas ...

Molluscs of the United States Endangered fauna of California Gastropods described in 1852