common grey sea slug vs

Aeolidia papillosa compared with Usnea cornuta

Key Differences

common grey sea slug is Least Concern while is Near Threatened.

Taxonomic Classification

Rank	common grey sea slug
Kingdom	Animalia (Animals)	Fungi (Fungi)
Phylum	Mollusca (Mollusks)	Ascomycota (Sac Fungi)
Class	Gastropoda (Gastropoda)	Lecanoromycetes (Lecanoromycetes)
Order	Nudibranchia (Nudibranchia)	Lecanorales (Lecanorales)
Family	Aeolidiidae	Parmeliaceae
Genus	Aeolidia	Usnea
Species	Aeolidia papillosa	Usnea cornuta

Conservation Status

common grey sea slug

LC — Least Concern

NT — Near Threatened

Physical Characteristics

Attribute	common grey sea slug
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

common grey sea slug

Habitat

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

Range

Distributed across Belgium, Chile, Denmark, Norway, and Sweden.

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway, Portugal, and Sweden. Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

common grey sea slug

<em>Aeolidia papillosa</em>, commonly known as the common grey sea slug, is a nudibranch mollusc belonging to the genus Aeolidia within the family Aeolidiidae. Despite the species name referencing terrestrial and aquatic habitats including forests and freshwater, <em>Aeolidia papillosa</em> is primarily a marine organism. Its range includes Belgium, Chile, Denmark, Norway, and Sweden, indicating a distribution across the North Atlantic and into South American waters. Common grey sea slug is assessed as Least Concern on the IUCN Red List. The species is typically found in intertidal and subtidal zones, where it preys on sea anemones and stores stinging cells from its prey in its dorsal cerata for defense. Biological traits of this species remain poorly documented in the scientific literature.

Usnea cornuta is a fruticose lichen in the family Parmeliaceae, assessed as Near Threatened (NT). It forms shrubby, branching thalli that hang from tree branches and twigs, typically in humid forest environments. Like all Usnea species, it is highly sensitive to air pollution, particularly sulfur dioxide, making it a useful bioindicator of air quality.