Coastal Silver-stiletto vs Common Stonewort

Acrosathe annulata compared with Chara vulgaris

Key Differences

• Coastal Silver-stiletto is Least Concern while Common Stonewort is Endangered.

Taxonomic Classification

Rank	Coastal Silver-stiletto	Common Stonewort
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Charophyta (Charophyta)
Class	Insecta (Insects)	Charophyceae (Charophyceae)
Order	Diptera (Diptera)	Charales (Charales)
Family	Therevidae	Characeae
Genus	Acrosathe	Chara
Species	Acrosathe annulata	Chara vulgaris

Conservation Status

Coastal Silver-stiletto

LC — Least Concern

Common Stonewort

EN — Endangered

Physical Characteristics

Attribute	Coastal Silver-stiletto	Common Stonewort
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 Stonewort

Habitat

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

Range

Widely distributed across Asia (Taiwan), Europe (Denmark, Norway, Sweden), North America (United States), and South America (Brazil). Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

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 Stonewort

<em>Chara vulgaris</em>, the common stonewort, is a species of charophyte green alga in the family Characeae, order Charales. It typically grows submerged in freshwater habitats including ponds, lakes, ditches, and slow-moving streams, often forming dense mats on the substrate. The species has a broad geographic distribution spanning Asia, Europe, and the Americas, tolerating a range of water conditions from clear to moderately turbid. <em>Chara vulgaris</em> is notable for its heavily calcified, whorled structure that gives stoneworts their characteristic encrusted appearance and makes them valuable as paleoclimate indicators in sediment records. As a primary producer, it contributes to aquatic food webs and provides habitat for invertebrates and juvenile fish. Biological traits such as individual lifespan, precise growth rates, and specific consumer relationships remain poorly documented in the literature. Despite its wide range, <em>Chara vulgaris</em> is assessed as Endangered by the IUCN, reflecting significant population declines attributed to freshwater pollution, eutrophication, and habitat degradation across much of its range. Targeted conservation of clean, oligotrophic water bodies is essential for its persistence.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden