vs European otter

Colacium simplex compared with Lutra lutra

Key Differences

is Not Evaluated while European otter is Vulnerable.

Taxonomic Classification

Rank		European otter
Kingdom	Protozoa (protozoa)	Animalia (Animals)
Phylum	Euglenozoa (Euglenozoa)	Chordata (Chordates)
Class	Euglenoidea (Euglenoidea)	Mammalia (Mammals)
Order	Euglenida (Euglenida)	Carnivora (Carnivorans)
Family	Euglenaceae	Mustelidae (Weasels & Otters)
Genus	Colacium	Lutra (Otters)
Species	Colacium simplex	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.

Colacium simplex is a photosynthetic euglenoid protist in the family Euglenaceae, notable for its epibiotic lifestyle as a stalked organism colonizing the surfaces of freshwater crustaceans and other zooplankton. This microscopic species belongs to a genus that bridges free-swimming euglenoid behavior and sessile, colonial existence, attaching to hosts via mucilaginous stalks. Colacium simplex, as its name implies, exhibits a relatively uncomplicated morphology compared to other genus members, with simple colony structures that anchor to copepods, cladocerans, and occasionally other small invertebrates. The organism photosynthesizes when light is available, using chloroplasts derived from the green algal endosymbiont common to euglenoids, while potentially employing osmotrophic nutrition in darker conditions. Its presence on zooplankton hosts can affect host swimming behavior and, in heavy infestations, may impose a metabolic cost on the carrier. Colacium simplex inhabits lentic and slow-moving lotic freshwater systems globally, wherever appropriate zooplankton hosts occur. It plays a role in microbial community structure and organic matter dynamics in planktonic food webs. Taxonomic understanding of the genus continues to evolve with molecular phylogenetic studies.

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.