common sea hare vs thick-lipped risso snail

Aplysia punctata compared with Rissoa membranacea

Taxonomic Classification

Rank	common sea hare	thick-lipped risso snail
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Mollusca (Mollusks)	Mollusca (Mollusks)
Class same	Gastropoda (Gastropoda)	Gastropoda (Gastropoda)
Order	Aplysiida (Aplysiida)	Littorinimorpha (Littorinimorpha)
Family	Aplysiidae	Rissoidae
Genus	Aplysia	Rissoa
Species	Aplysia punctata	Rissoa membranacea

Evolutionary Relationship

common sea hare and thick-lipped risso snail share a common ancestor at the Class level: Gastropoda. (Gastropoda)

Conservation Status

common sea hare

LC — Least Concern

thick-lipped risso snail

LC — Least Concern

Physical Characteristics

Attribute	common sea hare	thick-lipped risso snail
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

common sea hare

Habitat

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

Range

Distributed across Denmark, Norway, Portugal, and Sweden.

thick-lipped risso snail

Habitat

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

Range

Distributed across Denmark, Norway, and Sweden.

common sea hare

<em>Aplysia punctata</em>, the common sea hare, is a large opisthobranch sea slug in the family Aplysiidae, order Aplysiida, found in the northeastern Atlantic Ocean and Mediterranean Sea, with confirmed records from Denmark, Norway, Portugal, and Sweden. This species typically inhabits shallow subtidal and intertidal zones with abundant macroalgae, feeding primarily on red and green algae — a diet that influences the color of the defensive purple ink it secretes when threatened. <em>Aplysia punctata</em> is a simultaneous hermaphrodite, capable of acting as both male and female during mating, and often forms mating chains involving multiple individuals. It can reach considerable size among European opisthobranch species, though body dimensions vary considerably with age and feeding conditions. The species is classified as Least Concern by the IUCN, reflecting stable populations across its coastal range. Biological traits for this species remain poorly documented in the scientific literature, including precise average data on lifespan, body length, weight, and detailed seasonal dietary patterns, though its general herbivorous feeding on macroalgae is well established.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden