common freshwater nerite vs Common Roller

Theodoxus fluviatilis compared with Ancylis badiana

Taxonomic Classification

Rank	common freshwater nerite	Common Roller
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Mollusca (Mollusks)	Arthropoda (Arthropods)
Class	Gastropoda (Gastropoda)	Insecta (Insects)
Order	Cycloneritida (Cycloneritida)	Lepidoptera (Butterflies & Moths)
Family	Neritidae	Tortricidae
Genus	Theodoxus	Ancylis
Species	Theodoxus fluviatilis	Ancylis badiana

Evolutionary Relationship

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

Conservation Status

common freshwater nerite

LC — Least Concern

Common Roller

LC — Least Concern

Physical Characteristics

Attribute	common freshwater nerite	Common Roller
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 Roller

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

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 Roller

<em>Ancylis badiana</em>, the common roller, is a small moth in the family Tortricidae, order Lepidoptera. It is distributed across northwestern Europe, with documented records from Belgium, Denmark, Norway, and Sweden, typically inhabiting woodland margins, hedgerows, scrubland, and areas where its larval host plants are abundant. The species is assessed as Least Concern on the IUCN Red List. Tortricid moths in the genus Ancylis are commonly known as "rollers" or "leafrollers" because their larvae typically roll or fold leaves of host plants to create sheltered feeding structures. <em>Ancylis badiana</em> larvae feed on the foliage of various herbaceous plants, particularly species in the pea family (Fabaceae). Adults are small moths with intricately patterned wings that provide camouflage against bark and plant material. Adult moths are primarily nocturnal and are attracted to light, while larvae are cryptic within their leaf shelters. Biological traits such as lifespan, body measurements, and detailed diet host range remain poorly documented beyond general family-level characteristics. The species typically completes one to two generations per year in temperate European climates, overwintering as pupae. It is considered a minor component of invertebrate biodiversity in European lowland habitats.

Shared Countries

Both species can be found in 4 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden