Capped Orb Mussel vs small tortoiseshell

Musculium lacustre compared with Aglais urticae

Key Differences

• Capped Orb Mussel is Least Concern while small tortoiseshell is Near Threatened.

Taxonomic Classification

Rank	Capped Orb Mussel	small tortoiseshell
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Mollusca (Mollusks)	Arthropoda (Arthropods)
Class	Bivalvia (Bivalvia)	Insecta (Insects)
Order	Sphaeriida (Sphaeriida)	Lepidoptera (Butterflies & Moths)
Family	Sphaeriidae	Nymphalidae (Brush-footed Butterflies)
Genus	Musculium	Aglais
Species	Musculium lacustre	Aglais urticae

Evolutionary Relationship

Capped Orb Mussel and small tortoiseshell share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Capped Orb Mussel

LC — Least Concern

small tortoiseshell

NT — Near Threatened

Physical Characteristics

Attribute	Capped Orb Mussel	small tortoiseshell
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Capped Orb Mussel

Habitat

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

Range

Distributed across Denmark, Norway, Sweden, and United States.

small tortoiseshell

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (41 countries). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

Capped Orb Mussel

The Capped Orb Mussel (Musculium lacustre) is a species in the genus Musculium. It is currently classified as Least Concern (LC) on the IUCN Red List. Native to Europe and North America, inhabiting ecosystems characteristic of the region.

small tortoiseshell

small tortoiseshell (Aglais urticae) is classified as Near Threatened (NT) on the IUCN Red List. Close to qualifying as threatened, with populations that may become vulnerable without conservation action.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden