bladderwort vs Coastal Silver-stiletto

Utricularia australis compared with Acrosathe annulata

Key Differences

bladderwort is Vulnerable while Coastal Silver-stiletto is Least Concern.

Taxonomic Classification

Rank	bladderwort	Coastal Silver-stiletto
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Magnoliophyta (Flowering Plants)	Arthropoda (Arthropods)
Class	Magnoliopsida (Dicots)	Insecta (Insects)
Order	Lamiales (Lamiales)	Diptera (Diptera)
Family	Lentibulariaceae	Therevidae
Genus	Utricularia	Acrosathe
Species	Utricularia australis	Acrosathe annulata

Conservation Status

bladderwort

VU — Vulnerable

Coastal Silver-stiletto

LC — Least Concern

Physical Characteristics

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

Habitat & Geographic Range

bladderwort

Habitat

Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

Range

Found across Asia (Taiwan) and Europe (5 countries). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Coastal Silver-stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

bladderwort

The Bladderwort (Utricularia australis) is a species in the genus Utricularia. It is currently classified as Vulnerable on the IUCN Red List. Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

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.