common grey sea slug vs common razor clam

Aeolidia papillosa compared with Ensis ensis

Taxonomic Classification

Rank	common grey sea slug	common razor clam
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Mollusca (Mollusks)	Mollusca (Mollusks)
Class	Gastropoda (Gastropoda)	Bivalvia (Bivalvia)
Order	Nudibranchia (Nudibranchia)	Adapedonta (Adapedonta)
Family	Aeolidiidae	Pharidae
Genus	Aeolidia	Ensis
Species	Aeolidia papillosa	Ensis ensis

Evolutionary Relationship

common grey sea slug and common razor clam share a common ancestor at the Phylum level: Mollusca. (Mollusks)

Conservation Status

common grey sea slug

LC — Least Concern

common razor clam

LC — Least Concern

Physical Characteristics

Attribute	common grey sea slug	common razor clam
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.

common razor clam

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

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.

common razor clam

<em>Ensis ensis</em>, the common razor clam, is a bivalve mollusk in the family Pharidae, order Adapedonta. It is distributed along the northeastern Atlantic coastline, with documented populations in Belgium, Denmark, Norway, and Sweden. The species is assessed as Least Concern by the IUCN, suggesting stable populations across much of its range. Common razor clams typically inhabit sandy intertidal and shallow subtidal zones, burrowing rapidly into sediment using their muscular foot to evade predators and avoid desiccation. Their elongated shell, resembling an old-fashioned straight razor, is a distinctive morphological feature of the genus Ensis. <em>Ensis ensis</em> is a suspension feeder, typically drawing in water and filtering phytoplankton and organic particles through its siphons. This feeding strategy makes it an important component of coastal benthic communities. Razor clams play an ecological role as both filter feeders improving water clarity and as prey items for shorebirds, flatfish, and marine mammals. Biological traits such as precise lifespan, body measurements, and diet composition vary across populations and remain incompletely characterized. The species is commercially harvested in parts of its range and is considered a minor fishery resource in Scandinavian waters.

Shared Countries

Both species can be found in 4 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden