vs European otter

Cliostomum leprosum compared with Lutra lutra

Taxonomic Classification

Rank		European otter
Kingdom	Fungi (Fungi)	Animalia (Animals)
Phylum	Ascomycota (Sac Fungi)	Chordata (Chordates)
Class	Lecanoromycetes (Lecanoromycetes)	Mammalia (Mammals)
Order	Lecanorales (Lecanorales)	Carnivora (Carnivorans)
Family	Ramalinaceae	Mustelidae (Weasels & Otters)
Genus	Cliostomum	Lutra (Otters)
Species	Cliostomum leprosum	Lutra lutra

Conservation Status

VU — Vulnerable

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 and North America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway, Sweden, and United States. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

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.

Cliostomum leprosum is a crustose lichen-forming fungus in the family Ramalinaceae, notable for its powdery, leprose thallus that gives it a granular, mealy appearance on bark and wood substrates. Unlike many lichens that form well-defined, structured thalli, C. leprosum produces a loosely coherent sorediose crust ranging from pale greenish-grey to whitish, often colonizing deeply shaded, moist bark on deciduous and coniferous trees. The species is distributed across boreal and temperate forests of Europe and North America, with confirmed records from Norway, Sweden, and scattered locations in the United States. It photosynthesizes in partnership with green algal partners typical of crustose lichens. Cliostomum leprosum is assessed as Vulnerable due to its sensitivity to air pollution, particularly sulfur dioxide and nitrogen compounds that degrade lichen communities. Its decline is linked to habitat loss from intensive forestry, removal of veteran trees, and acidic deposition. Conservation efforts focus on preserving old-growth and semi-natural forest stands that provide suitable, low-disturbance bark microhabitats where this inconspicuous but ecologically significant lichen can persist.

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.