vs common grey sea slug

Bacidia rosella compared with Aeolidia papillosa

Key Differences

is Critically Endangered while common grey sea slug is Least Concern.

Taxonomic Classification

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

Conservation Status

CR — Critically Endangered

common grey sea slug

LC — Least Concern

Physical Characteristics

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

Habitat & Geographic Range

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and boreal forests and taiga, among 5 distinct biome types within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Distributed across Denmark, Norway, Portugal, Sweden, and United States. Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its 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.

Bacidia rosella is a crustose lichen in the family Ramalinaceae, assessed as Critically Endangered (CR). It grows on the smooth bark of ancient trees in old-growth woodland habitats with long ecological continuity. Its critically endangered status reflects extreme rarity and the near-total loss of suitable veteran tree habitats across its range.

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.