Atlantic Ancula vs St. James' shell

Ancula gibbosa compared with Pecten maximus

Taxonomic Classification

Rank	Atlantic Ancula	St. James' shell
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Mollusca (Mollusks)	Mollusca (Mollusks)
Class	Gastropoda (Gastropoda)	Bivalvia (Bivalvia)
Order	Nudibranchia (Nudibranchia)	Pectinida (Pectinida)
Family	Goniodorididae	Pectinidae
Genus	Ancula	Pecten
Species	Ancula gibbosa	Pecten maximus

Evolutionary Relationship

Atlantic Ancula and St. James' shell share a common ancestor at the Phylum level: Mollusca. (Mollusks)

Conservation Status

Atlantic Ancula

LC — Least Concern

St. James' shell

LC — Least Concern

Physical Characteristics

Attribute	Atlantic Ancula	St. James' shell
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Atlantic Ancula

Habitat

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

Range

Distributed across Denmark, Norway, and Sweden.

St. James' shell

Habitat

Native to Asia and Europe and South America, inhabiting ecosystems characteristic of the region.

Range

Widely distributed across Asia (China), Europe (8 countries), and South America (Chile).

Atlantic Ancula

The Atlantic Ancula (Ancula gibbosa) is a species in the genus Ancula. It is currently classified as Least Concern on the IUCN Red List. Typically found in terrestrial and aquatic habitats including forests and freshwater.

St. James' shell

St. James' shell (Pecten maximus) is classified as Least Concern (LC) on the IUCN Red List. Widespread and abundant across its range, with stable populations and no immediate conservation concerns.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden