Coastal Silver-stiletto vs common razor clam

Acrosathe annulata compared with Ensis ensis

Taxonomic Classification

Rank	Coastal Silver-stiletto	common razor clam
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Arthropoda (Arthropods)	Mollusca (Mollusks)
Class	Insecta (Insects)	Bivalvia (Bivalvia)
Order	Diptera (Diptera)	Adapedonta (Adapedonta)
Family	Therevidae	Pharidae
Genus	Acrosathe	Ensis
Species	Acrosathe annulata	Ensis ensis

Evolutionary Relationship

Coastal Silver-stiletto and common razor clam share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Coastal Silver-stiletto

LC — Least Concern

common razor clam

LC — Least Concern

Physical Characteristics

Attribute	Coastal Silver-stiletto	common razor clam
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Coastal Silver-stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, 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.

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.

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