arrow-finned squid vs common grey sea slug

Illex oxygonius compared with Aeolidia papillosa

Taxonomic Classification

Rank	arrow-finned squid	common grey sea slug
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Mollusca (Mollusks)	Mollusca (Mollusks)
Class	Cephalopoda (Cephalopods)	Gastropoda (Gastropoda)
Order	Oegopsida (Oegopsida)	Nudibranchia (Nudibranchia)
Family	Ommastrephidae	Aeolidiidae
Genus	Illex	Aeolidia
Species	Illex oxygonius	Aeolidia papillosa

Evolutionary Relationship

arrow-finned squid and common grey sea slug share a common ancestor at the Phylum level: Mollusca. (Mollusks)

Conservation Status

arrow-finned squid

LC — Least Concern

common grey sea slug

LC — Least Concern

Physical Characteristics

Attribute	arrow-finned squid	common grey sea slug
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

arrow-finned squid

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.

arrow-finned squid

The Arrow-finned squid, Illex oxygonius, is a species. It is currently assessed as least concern on the IUCN Red List.

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.