common freshwater nerite vs Delacour's langur

Theodoxus fluviatilis compared with Trachypithecus delacouri

Key Differences

• common freshwater nerite is Least Concern while Delacour's langur is Critically Endangered.

Taxonomic Classification

Rank	common freshwater nerite	Delacour's langur
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Mollusca (Mollusks)	Chordata (Chordates)
Class	Gastropoda (Gastropoda)	Mammalia (Mammals)
Order	Cycloneritida (Cycloneritida)	Primates (Primates)
Family	Neritidae	Cercopithecidae (Old World Monkeys)
Genus	Theodoxus	Trachypithecus
Species	Theodoxus fluviatilis	Trachypithecus delacouri

Evolutionary Relationship

common freshwater nerite and Delacour's langur share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

common freshwater nerite

LC — Least Concern

Delacour's langur

CR — Critically Endangered

Physical Characteristics

Attribute	common freshwater nerite	Delacour's langur
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).

Delacour's langur

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

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.