common sea hare vs flat-backed millipede

Aplysia punctata compared with Polydesmus complanatus

Taxonomic Classification

Rank	common sea hare	flat-backed millipede
Kingdom same	Animalia (حيوانات)	Animalia (حيوانات)
Phylum	Mollusca (رخويات)	Arthropoda (مفصليات الأرجل)
Class	Gastropoda (بطنيات القدم)	Diplopoda (ألفية الأرجل)
Order	Aplysiida (Aplysiida)	Polydesmida (متعددة الأربطة)
Family	Aplysiidae	Polydesmidae
Genus	Aplysia	Polydesmus
Species	Aplysia punctata	Polydesmus complanatus

Evolutionary Relationship

common sea hare and flat-backed millipede share a common ancestor at the Kingdom level: Animalia. (حيوانات)

Conservation Status

common sea hare

LC — Least Concern

flat-backed millipede

LC — Least Concern

Physical Characteristics

Attribute	common sea hare	flat-backed millipede
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.

flat-backed millipede

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

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