vs Coastal Silver-stiletto

Chrysosphaerella longispina compared with Acrosathe annulata

Key Differences

is Not Evaluated while Coastal Silver-stiletto is Least Concern.

Taxonomic Classification

Rank		Coastal Silver-stiletto
Kingdom	Chromista (Chromista)	Animalia (Animals)
Phylum	Ochrophyta (Ochrophyta)	Arthropoda (Arthropods)
Class	Chrysophyceae (Chrysophyceae)	Insecta (Insects)
Order	Ochromonadales (Ochromonadales)	Diptera (Diptera)
Family	Paraphysomonadaceae	Therevidae
Genus	Chrysosphaerella	Acrosathe
Species	Chrysosphaerella longispina	Acrosathe annulata

Conservation Status

NE — Not Evaluated

Coastal Silver-stiletto

LC — Least Concern

Physical Characteristics

Attribute		Coastal Silver-stiletto
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

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.

Chrysosphaerella longispina is a colonial chrysophyte alga in the genus Chrysosphaerella, notable for the long silica spines (longispina: Latin, long spine) that project from each cell in the colony. The genus is characterized by spherical or discoid colonies of photosynthetic cells that each secrete siliceous scales and elongated spine-like appendages, making Chrysosphaerella colonies distinctively bristled and visible under light microscopy. The long spines of C. longispina likely serve as anti-predation structures that make the colonies more difficult for zooplankton to ingest. C. longispina is found in cold, oligotrophic freshwater lakes, particularly in Scandinavia, where comprehensive chrysophyte surveys have documented its presence. Chrysosphaerella colonies contribute to freshwater primary production and the cycling of biogenic silica, which upon cell dissolution is deposited in lake sediments as microscopically identifiable remains. These silica structures are widely used by paleolimnologists to reconstruct past changes in lake water chemistry, thermal stratification, and climate. The conservation status of C. longispina has not been assessed by the IUCN; the species is listed as Not Evaluated.

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.