Bladder Fern vs European otter

Cystopteris fragilis compared with Lutra lutra

Key Differences

Bladder Fern is Not Evaluated while European otter is Vulnerable.

Taxonomic Classification

Rank	Bladder Fern	European otter
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Tracheophyta	Chordata (Chordates)
Class	Polypodiopsida (Polypodiopsida)	Mammalia (Mammals)
Order	Polypodiales (Polypodiales)	Carnivora (Carnivorans)
Family	Cystopteridaceae	Mustelidae (Weasels & Otters)
Genus	Cystopteris	Lutra (Otters)
Species	Cystopteris fragilis	Lutra lutra

Conservation Status

Bladder Fern

NE — Not Evaluated

European otter

VU — Vulnerable

Trend: Stable →

Physical Characteristics

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

Habitat & Geographic Range

Bladder Fern

Habitat

Typically found in moist, shaded forest floors and tropical canopies.

Range

Widely distributed across Asia (Taiwan), Europe (6 countries), North America (Canada, United States), and South America (Colombia).

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.

Bladder Fern

The Bladder Fern (Cystopteris fragilis) is a species in the genus Cystopteris. Typically found in moist, shaded forest floors and tropical canopies.

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.