''Laevapex fuscus'', the dusky ancylid, is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of small,

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does in ...

, air-breathing

limpet Limpets are a group of aquatic snails that exhibit a conical gastropod shell, shell shape (patelliform) and a strong, muscular foot. Limpets are members of the class Gastropoda, but are polyphyletic, meaning the various groups called "limpets" ...

, an aquatic pulmonate gastropod mollusc or micromollusc in the family Planorbidae, the ram's horn snails and their allies.

Geographic distribution

''L. fuscus'' is found throughout North America east of the Great Plains, except for mountainous areas. It has been recorded in

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tota ...

, the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

Jamaica Jamaica (; ) is an island country situated in the Caribbean Sea. Spanning in area, it is the third-largest island of the Greater Antilles and the Caribbean (after Cuba and Hispaniola). Jamaica lies about south of Cuba, and west of Hispan ...

and

Puerto Rico Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and Unincorporated ...

Description

''L. fuscus'' was originally described as ''Ancylus fuscus'' in 1841 by

Charles Baker Adams Charles Baker Adams (January 11, 1814 – January 19, 1853) was an American educator and naturalist. Biography He was born in Dorchester, Massachusetts in 1814, the son of Charles J. Adams and Hannah Baker. He graduated from Phillips Academy in ...

: :"'' Shell'' thin, transparent without the epidermis, not much elevated, elliptical, moderately curved at the sides; ''epidermis'' brown, visible through the shell, giving it the appearance of having the same color, thick, rough, slightly extending beyond the margin of the shell; '' apex'' obtuse, moderately prominent, scarcely behind the middle, inclining to the right, so as to have only two fifths of the width on that side. :Length, , width, ; height, ."

Habitat and ecology

''L. fuscus'' generally occurs in lacustrine

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s, preferring calmer waters than other ancylid genera. Simple annual ( univoltine) and two-generation per year ( bivoltine) life cycles have been reported in New York populations of ''L. fuscus''. The bioenergetic data collected for the species suggest that its reproductive effort is in line with expectation from adult weight, and hence that its life history strategy is undifferentiated. The species is functionally

protandric Sequential hermaphroditism (called dichogamy in botany) is a type of hermaphroditism that occurs in many fish, gastropods, and plants. Sequential hermaphroditism occurs when the individual changes its sex at some point in its life. In particular, ...

, despite being one of the more specialised of higher limnic pulmonate snails. ''L. fuscus'' has been observed attached to the wings or

hemelytra An elytron (; ; , ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometimes alterna ...

of the water bug species ''

Belostoma flumineum ''Belostoma flumineum'' is a North American species of giant water bug (family Belostomatidae). They are a common predator in ponds and wetlands. They are relatively large, reaching in length. As with other species of the Belostomatidae family ...

'' ( Hemiptera: Belostomatidae). This observation suggests that belostomatids might serve as a mode of transport and a passive dispersal agent for ''L. fuscus'' and other ancylid species.

References

{{Taxonbar, from=Q3691592 Planorbidae Molluscs of North America Freshwater animals of North America Gastropods described in 1841 Taxa named by Charles Baker Adams

Geographic distribution

Description

Habitat and ecology

See also

References