Black-Necked Grebe vs common sea hare

Podiceps nigricollis compared with Aplysia punctata

Key Differences

• Black-Necked Grebe is Endangered while common sea hare is Least Concern.

Taxonomic Classification

Rank	Black-Necked Grebe	common sea hare
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Chordata (Chordates)	Mollusca (Mollusks)
Class	Aves (Birds)	Gastropoda (Gastropoda)
Order	Podicipediformes (Podicipediformes)	Aplysiida (Aplysiida)
Family	Podicipedidae	Aplysiidae
Genus	Podiceps	Aplysia
Species	Podiceps nigricollis	Aplysia punctata

Evolutionary Relationship

Black-Necked Grebe and common sea hare share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Black-Necked Grebe

EN — Endangered

common sea hare

LC — Least Concern

Physical Characteristics

Attribute	Black-Necked Grebe	common sea hare
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Black-Necked Grebe

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and boreal forests and taiga, among 8 distinct biome types within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found across Europe (5 countries) and North America (United States). Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

common sea hare

Habitat

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

Range

Distributed across Denmark, Norway, Portugal, and Sweden.

Black-Necked Grebe

Black-Necked Grebe (Podiceps nigricollis) is classified as Endangered (EN) on the IUCN Red List. At high risk of extinction in the wild, with significant population decline and ongoing threats to survival.

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