common bubble snail vs Common Frillwort

Akera bullata compared with Fossombronia pusilla

Key Differences

• common bubble snail is Least Concern while Common Frillwort is Critically Endangered.

Taxonomic Classification

Rank	common bubble snail	Common Frillwort
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Mollusca (Mollusks)	Marchantiophyta (liverwort)
Class	Gastropoda (Gastropoda)	Jungermanniopsida (Jungermanniopsida)
Order	Aplysiida (Aplysiida)	Fossombroniales (Fossombroniales)
Family	Akeridae	Fossombroniaceae
Genus	Akera	Fossombronia
Species	Akera bullata	Fossombronia pusilla

Conservation Status

common bubble snail

LC — Least Concern

Common Frillwort

CR — Critically Endangered

Physical Characteristics

Attribute	common bubble snail	Common Frillwort
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

common bubble snail

Habitat

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

Range

Distributed across Denmark, Norway, Portugal, and Sweden.

Common Frillwort

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, temperate broadleaf and mixed forests, and Mediterranean forests and woodlands spanning the Indomalayan and Palearctic realms. Populations are also found in montane and highland environments at higher elevations.

Range

Found across Asia (Taiwan) and Europe (5 countries). Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

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.

Common Frillwort

<em>Fossombronia pusilla</em>, commonly known as the common frillwort, is a small liverwort belonging to the family Fossombroniaceae within the division Marchantiophyta. This non-vascular bryophyte typically grows in moist, disturbed soils, clay banks, and damp pathways across its range in Europe and parts of Asia. The thallus is typically lobed and frilly in appearance, giving the species its common name. <em>Fossombronia pusilla</em> favors habitats with high moisture and reduced competition, often colonizing bare or sparsely vegetated ground following disturbance. Its geographic range spans temperate regions of western and central Europe into Asia, though populations have become increasingly fragmented. The species is currently assessed as Critically Endangered on the IUCN Red List, reflecting severe population declines likely driven by habitat loss, land drainage, and agricultural intensification. Biological traits such as lifespan, body size, and diet remain poorly documented for this species, as is common among many small bryophyte taxa. Like other liverworts, <em>Fossombronia pusilla</em> reproduces both sexually through spores and vegetatively. Conservation of this species depends on protecting moist, low-competition microhabitats and reducing disturbance to its specialized substrates.

Shared Countries

Both species can be found in 3 countries:

🇳🇴 Norway 🇵🇹 Portugal 🇸🇪 Sweden