Bladder Fern vs common bubble snail

Cystopteris fragilis compared with Akera bullata

Key Differences

• Bladder Fern is Not Evaluated while common bubble snail is Least Concern.

Taxonomic Classification

Rank	Bladder Fern	common bubble snail
Kingdom	Plantae (植物)	Animalia (动物界)
Phylum	Tracheophyta	Mollusca (软体动物门)
Class	Polypodiopsida (水龍骨綱)	Gastropoda (腹足纲)
Order	Polypodiales (水龙骨目)	Aplysiida (海鹿目)
Family	Cystopteridaceae	Akeridae
Genus	Cystopteris	Akera
Species	Cystopteris fragilis	Akera bullata

Conservation Status

Bladder Fern

NE — Not Evaluated

common bubble snail

LC — Least Concern

Physical Characteristics

Attribute	Bladder Fern	common bubble snail
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

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).

common bubble snail

Habitat

Typically found in terrestrial and aquatic habitats including forests and freshwater.

Range

Distributed across Denmark, Norway, Portugal, and Sweden.

Bladder Fern

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

common bubble snail

The common bubble snail (<em>Akera bullata</em>) is a marine gastropod mollusc found in the coastal waters of Denmark, Norway, Portugal, and Sweden. This species typically inhabits terrestrial and aquatic environments including forests and freshwater-adjacent marine areas, often occurring in shallow subtidal and intertidal zones of temperate European seas. It is classified as Least Concern on the IUCN Red List. As a member of the family Akeridae, the common bubble snail is characterized by its thin, fragile shell and its ability to swim briefly by flapping its large, wing-like parapodia. The species often forages on algae and detritus in sandy and muddy seafloor habitats, particularly in sheltered bays and estuaries. The common bubble snail typically aggregates in large numbers during the spawning season, producing gelatinous egg masses. Biological traits of this species remain poorly documented in the scientific literature.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden