vs Coastal Silver-stiletto

Chroococcus minutus compared with Acrosathe annulata

Key Differences

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

Taxonomic Classification

Rank		Coastal Silver-stiletto
Kingdom	Bacteria (Bacteria)	Animalia (Animals)
Phylum	Cyanobacteria (Cyanobacteria)	Arthropoda (Arthropods)
Class	Cyanobacteriia	Insecta (Insects)
Order	Cyanobacteriales	Diptera (Diptera)
Family	Microcystaceae	Therevidae
Genus	Chroococcus	Acrosathe
Species	Chroococcus minutus	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.

Chroococcus minutus is a cyanobacterium in the family Chroococcaceae, recognized as one of the smaller species in the genus. It is distributed in freshwater habitats across temperate regions, including Scandinavia and northern Europe, where it has been documented in taxonomic surveys of freshwater algae and cyanobacteria. Chroococcus species in general are characterized by their simple morphology — spherical or hemispherical cells, binary fission, and organization into pairs or tetrads within gelatinous sheaths. Chroococcus minutus occurs in the plankton and periphyton of lakes, ponds, and slowly flowing waters with low to moderate nutrient levels. Cyanobacteria of this type play roles in primary production and, in certain metabolically active strains, may contribute to nitrogen fixation in nitrogen-limited aquatic systems. The taxonomy of small-celled Chroococcus species remains challenging, with morphological overlap between species and significant variation in cell size related to environmental conditions and growth stage. Recent molecular studies have revealed that morphologically defined genera such as Chroococcus represent multiple phylogenetic lineages, indicating likely future taxonomic rearrangements. The species is not assessed by the IUCN.

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.