common bubble snail vs common hydra

Akera bullata compared with Hydra vulgaris

Key Differences

• common bubble snail is Least Concern while common hydra is Not Evaluated.

Taxonomic Classification

Rank	common bubble snail	common hydra
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Mollusca (Mollusks)	Cnidaria (Cnidarians)
Class	Gastropoda (Gastropoda)	Hydrozoa (Hydrozoa)
Order	Aplysiida (Aplysiida)	Anthoathecata (Anthoathecata)
Family	Akeridae	Hydridae
Genus	Akera	Hydra
Species	Akera bullata	Hydra vulgaris

Evolutionary Relationship

common bubble snail and common hydra share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

common bubble snail

LC — Least Concern

common hydra

NE — Not Evaluated

Physical Characteristics

Attribute	common bubble snail	common hydra
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 hydra

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, and Sweden.

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 hydra

<em>Hydra vulgaris</em>, commonly known as the common hydra, is a small freshwater cnidarian in the family Hydridae. Its conservation status has not been formally evaluated by the IUCN. The species is recorded from Denmark, Norway, and Sweden, with its native range understood to encompass Europe broadly. It typically inhabits slow-moving or still freshwater bodies such as ponds, lakes, and streams, where it attaches to aquatic vegetation or submerged substrates. The common hydra is notable for its remarkable regenerative capabilities and has been the subject of substantial biological research. Diet information for this species is not available in current records. 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