vs European otter

Chrysococcus minutus compared with Lutra lutra

Key Differences

is Not Evaluated while European otter is Vulnerable.

Taxonomic Classification

Rank		European otter
Kingdom	Chromista (Chromista)	Animalia (Animals)
Phylum	Ochrophyta (Ochrophyta)	Chordata (Chordates)
Class	Chrysophyceae (Chrysophyceae)	Mammalia (Mammals)
Order	Chromulinales (Chromulinales)	Carnivora (Carnivorans)
Family	Dinobryaceae	Mustelidae (Weasels & Otters)
Genus	Chrysococcus	Lutra (Otters)
Species	Chrysococcus minutus	Lutra lutra

Conservation Status

NE — Not Evaluated

European otter

VU — Vulnerable

Trend: Stable →

Physical Characteristics

Attribute		European otter
Diet	—	Carnivore
Average Lifespan	—	10 years
Average Length	—	1.0 m
Average Weight	—	10.0 kg

Habitat & Geographic Range

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, and Sweden.

European otter

Habitat

Typically found in diverse ecosystems where prey species are available.

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 minutus is a small loricate chrysophyte alga in the genus Chrysococcus, its epithet minutus (Latin: minute or very small) reflecting its diminutive cell dimensions. Like its congeners, the cell is enclosed within a lorica — a rigid, often silicified or organic housing with an apical pore through which the flagellum protrudes. The lorica shape and dimensions provide taxonomic characters for species differentiation within the genus. C. minutus inhabits freshwater environments, including oligotrophic lakes, bog pools, and slow-moving waters in temperate and subarctic regions. Chrysophytes thrive in cold, acidic, low-nutrient waters and serve as reliable bioindicators of water quality. The small cell size of C. minutus places it within the nanoplankton size class, making it an important prey item for heterotrophic nanoflagellates and small ciliates in the freshwater microbial food web. Some Chrysococcus species supplement photosynthesis with bacterivorous feeding. The species has not been evaluated for conservation status and is listed as Not Evaluated by the IUCN. Loricated chrysophytes like C. minutus leave fossil siliceous cysts (stomatocysts) in lake sediments, which are widely used in paleoecological reconstructions.

European otter

Sleek semi-aquatic mustelid found along clean rivers, streams, and coastlines across Europe and Asia. European otters can reach 1.3 meters in length and are highly skilled fish hunters, using sensitive whiskers to detect prey movements. Requiring unpolluted water with abundant fish, they are an indicator species for freshwater ecosystem health. Once nearly extinct in Western Europe from hunting and pollution, populations have recovered significantly following water quality improvements.