common freshwater nerite vs Common Least Skipper

Theodoxus fluviatilis compared with Ancyloxypha numitor

Taxonomic Classification

Rank	common freshwater nerite	Common Least Skipper
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Mollusca (Mollusks)	Arthropoda (Arthropods)
Class	Gastropoda (Gastropoda)	Insecta (Insects)
Order	Cycloneritida (Cycloneritida)	Lepidoptera (Butterflies & Moths)
Family	Neritidae	Hesperiidae
Genus	Theodoxus	Ancyloxypha
Species	Theodoxus fluviatilis	Ancyloxypha numitor

Evolutionary Relationship

common freshwater nerite and Common Least Skipper share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

common freshwater nerite

LC — Least Concern

Common Least Skipper

LC — Least Concern

Physical Characteristics

Attribute	common freshwater nerite	Common Least Skipper
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

common freshwater nerite

Habitat

Typically found in terrestrial and aquatic habitats including forests and freshwater.

Range

Found across Europe (11 countries).

Common Least Skipper

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Canada and United States.

common freshwater nerite

<em>Theodoxus fluviatilis</em>, commonly known as the common freshwater nerite, is a small aquatic gastropod mollusc belonging to the family Neritidae. This species is widely distributed across Europe, with documented occurrences in Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Hungary, Latvia, Norway, and Sweden. It typically inhabits freshwater environments, including rivers, streams, and lakes, where it grazes on algae and biofilm on hard substrates such as rocks and submerged wood. The common freshwater nerite is assessed as Least Concern on conservation metrics, reflecting its broad distribution and relatively stable populations across much of its European range. Biological traits of this species remain poorly documented in the scientific literature. <em>Theodoxus fluviatilis</em> plays an ecological role as a grazer in freshwater benthic communities, contributing to the regulation of algal growth on hard surfaces. The species typically favors clean, well-oxygenated waters and can serve as an indicator of water quality in freshwater systems. Its distinctive small, dome-shaped shell with variable patterning makes it recognizable among freshwater invertebrates.

Common Least Skipper

The Common Least Skipper (<em>Ancyloxypha numitor</em>) is a small butterfly in the family Hesperiidae, classified as Least Concern on the IUCN Red List. It is native to Canada and the United States, where it typically inhabits virtually all terrestrial and freshwater habitats within its range, showing a particular affinity for moist, grassy areas near water. The species is among the smallest skippers in North America, characterized by orange and brown wing coloration and a rapid, low-flying flight pattern close to vegetation. Adults typically nectar on small flowers while larvae feed on grasses, particularly those in wet meadows, marshes, stream margins, and disturbed grassy areas. The Common Least Skipper is frequently observed in wetland margins, wet prairies, and roadsides with rank grass growth. Its wide distribution across North America and habitat generalism across moist grassland and wetland types support its stable population and Least Concern conservation status. Biological traits of this species remain poorly documented in the scientific literature.