vs Eurasian beaver

Chrysococcus bisetus compared with Castor fiber

Key Differences

is Not Evaluated while Eurasian beaver is Vulnerable.

Taxonomic Classification

Rank		Eurasian beaver
Kingdom	Chromista (أسناخ صبغية)	Animalia (حيوانات)
Phylum	Ochrophyta (طحالب داكنة)	Chordata (حبليات)
Class	Chrysophyceae (طحالب ذهبية)	Mammalia (ثدييات)
Order	Chromulinales (Chromulinales)	Rodentia (قوارض)
Family	Dinobryaceae	Castoridae (Beavers)
Genus	Chrysococcus	Castor (Beavers)
Species	Chrysococcus bisetus	Castor fiber

Conservation Status

NE — Not Evaluated

Eurasian beaver

VU — Vulnerable

Physical Characteristics

Attribute		Eurasian beaver
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway and Sweden.

Eurasian beaver

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found across Europe (6 countries). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

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.

Eurasian beaver

Eurasian beaver (Castor fiber) is classified as Vulnerable (VU) on the IUCN Red List. Facing a high risk of endangerment in the wild, with declining populations and increasing habitat pressure.