Brook Floater vs Common Periwinkle

Alasmidonta varicosa compared with Littorina littorea

Key Differences

• Brook Floater is Vulnerable while Common Periwinkle is Least Concern.

Taxonomic Classification

Rank	Brook Floater	Common Periwinkle
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Mollusca (Mollusks)	Mollusca (Mollusks)
Class	Bivalvia (Bivalvia)	Gastropoda (Gastropoda)
Order	Unionida (Unionida)	Littorinimorpha (Littorinimorpha)
Family	Unionidae	Littorinidae
Genus	Alasmidonta	Littorina
Species	Alasmidonta varicosa	Littorina littorea

Evolutionary Relationship

Brook Floater and Common Periwinkle share a common ancestor at the Phylum level: Mollusca. (Mollusks)

Conservation Status

Brook Floater

VU — Vulnerable

Common Periwinkle

LC — Least Concern

Physical Characteristics

Attribute	Brook Floater	Common Periwinkle
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Brook Floater

Habitat

Native to North America, inhabiting ecosystems characteristic of the region.

Range

Found in United States. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Periwinkle

Habitat

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

Range

Found across Europe (4 countries) and North America (Canada, United States).

Brook Floater

The Brook Floater (Alasmidonta varicosa) is a species in the genus Alasmidonta. It is currently classified as Vulnerable on the IUCN Red List. Native to North America, inhabiting ecosystems characteristic of the region.

Common Periwinkle

Common Periwinkle (Littorina littorea) is classified as Least Concern (LC) on the IUCN Red List. Widespread and abundant across its range, with stable populations and no immediate conservation concerns.

Shared Countries

Both species can be found in 1 countries:

🇺🇸 United States