Atlantic Ancula vs Coastal Silver-stiletto

Ancula gibbosa compared with Acrosathe annulata

Taxonomic Classification

Rank	Atlantic Ancula	Coastal Silver-stiletto
Kingdom same	Animalia (प्राणी)	Animalia (प्राणी)
Phylum	Mollusca (मोलस्का)	Arthropoda (सन्धिपाद)
Class	Gastropoda (उदरपाद)	Insecta (कीट)
Order	Nudibranchia (Nudibranchia)	Diptera (मक्खी)
Family	Goniodorididae	Therevidae
Genus	Ancula	Acrosathe
Species	Ancula gibbosa	Acrosathe annulata

Evolutionary Relationship

Atlantic Ancula and Coastal Silver-stiletto share a common ancestor at the Kingdom level: Animalia. (प्राणी)

Conservation Status

Atlantic Ancula

LC — Least Concern

Coastal Silver-stiletto

LC — Least Concern

Physical Characteristics

Attribute	Atlantic Ancula	Coastal Silver-stiletto
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.

Coastal Silver-stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

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.

Coastal Silver-stiletto

Coastal silver stiletto (Acrosathe annulata) is a slender robber fly in the family Therevidae, native to northwestern Europe, including the United Kingdom, France, the Netherlands, Belgium, and Scandinavia. Adults are found on coastal sand dunes and sandy heathland, where they perch on bare sand to ambush small flying insects. Stiletto flies in the family Therevidae are characterised by a slender body, long pointed abdomen, and predatory habits; adults prey on a variety of small dipterans and other flying insects during warm, sunny periods. Larvae develop in sandy soil, where they are also predatory, feeding on other invertebrate larvae. Acrosathe annulata is a habitat specialist restricted to open, sandy coastal habitats with sparse vegetation—environments that have declined substantially across northwestern Europe due to dune stabilisation, recreational disturbance, and the cessation of traditional dune management. The IUCN lists it as Least Concern, though regional conservation bodies in the United Kingdom have flagged population declines. It is considered an indicator of high-quality coastal sand dune habitats and is monitored through national invertebrate surveys.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden