Black-Lined Periwinkle vs Brook Alder

Littorina saxatilis compared with Alnus maritima

Key Differences

• Black-Lined Periwinkle is Least Concern while Brook Alder is Endangered.

Taxonomic Classification

Rank	Black-Lined Periwinkle	Brook Alder
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Mollusca (Mollusks)	Magnoliophyta (Flowering Plants)
Class	Gastropoda (Gastropoda)	Magnoliopsida (Dicots)
Order	Littorinimorpha (Littorinimorpha)	Fagales (Beeches & Oaks)
Family	Littorinidae	Betulaceae
Genus	Littorina	Alnus
Species	Littorina saxatilis	Alnus maritima

Conservation Status

Black-Lined Periwinkle

LC — Least Concern

Brook Alder

EN — Endangered

Physical Characteristics

Attribute	Black-Lined Periwinkle	Brook Alder
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Black-Lined Periwinkle

Habitat

Found across multiple habitat types including tropical and subtropical grasslands and savannas, flooded grasslands and savannas, and deserts and xeric shrublands within the Afrotropic biogeographic realm.

Range

Widely distributed across Africa (Namibia, South Africa), Europe (5 countries), and North America (United States).

Brook Alder

Habitat

Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

Range

Distributed across Belgium, France, Netherlands, and United Kingdom. Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Black-Lined Periwinkle

The Black-Lined Periwinkle (Littorina saxatilis) is a species in the genus Littorina. It is currently classified as Least Concern on the IUCN Red List. Found across multiple habitat types including tropical and subtropical grasslands and savannas, flooded grasslands and savannas, and deserts and xeric shrublands within the Afrotropic biogeographic realm.

Brook Alder

The Brook Alder (Alnus maritima) is a species in the genus Alnus. It is currently classified as Endangered on the IUCN Red List. Typically found in diverse terrestrial habitats from tropical forests to temperate regions.