Brown Diving Beetle vs

Agabus brunneus compared with Chrysococcus bisetus

Key Differences

Brown Diving Beetle is Extinct while is Not Evaluated.

Taxonomic Classification

Rank	Brown Diving Beetle
Kingdom	Animalia (Animals)	Chromista (Chromista)
Phylum	Arthropoda (Arthropods)	Ochrophyta (Ochrophyta)
Class	Insecta (Insects)	Chrysophyceae (Chrysophyceae)
Order	Coleoptera (Beetles)	Chromulinales (Chromulinales)
Family	Dytiscidae	Dinobryaceae
Genus	Agabus	Chrysococcus
Species	Agabus brunneus	Chrysococcus bisetus

Conservation Status

Brown Diving Beetle

EX — Extinct

NE — Not Evaluated

Physical Characteristics

Attribute	Brown Diving Beetle
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Brown Diving Beetle

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium and Sweden.

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway and Sweden.

Brown Diving Beetle

The Brown Diving Beetle (Agabus brunneus) is a species in the genus Agabus. It is currently classified as Extinct on the IUCN Red List. Typically found in virtually all terrestrial and freshwater habitats.

Chrysococcus bisetus is a species of unicellular chrysophyte microalga in the genus Chrysococcus, class Chrysophyceae, order Chromulinales. The genus Chrysococcus is characterized by cells enclosed within a lorica — a secreted outer case or vesicle — through which flagella protrude, a structure that distinguishes it from many other chrysophytes. The epithet bisetus, meaning two-bristled, describes a diagnostic feature of the lorica, which bears two bristle-like projections used for species identification. Chrysococcus species inhabit freshwater and brackish environments, typically occurring in cool, nutrient-poor to moderately enriched lakes, ponds, and slow-flowing water bodies. C. bisetus has been recorded from Norwegian and Swedish waters, consistent with the historical focus of chrysophyte research in Scandinavian freshwater habitats, and also from Brazilian waters, suggesting a broader distribution. Chrysophytes including Chrysococcus species are important components of oligotrophic lake phytoplankton, where they contribute to primary production and serve as food for zooplankton. The golden-brown coloration of Chrysococcus arises from chlorophylls a and c together with fucoxanthin, pigments shared with other heterokonts. Unlike diatoms, chrysophytes produce chrysolaminarin as their storage carbohydrate rather than starch. C. bisetus has not been assessed under IUCN criteria and is listed as Not Evaluated. As with most freshwater microalgae, global population size and distribution are poorly characterized, limiting meaningful conservation assessment.