common hydra vs Polar bear

Hydra vulgaris compared with Ursus maritimus

Key Differences

common hydra is Not Evaluated while Polar bear is Vulnerable.

Taxonomic Classification

Rank	common hydra	Polar bear
Kingdom same	Animalia (動物)	Animalia (動物)
Phylum	Cnidaria (刺胞動物)	Chordata (脊索動物)
Class	Hydrozoa (ヒドロ虫綱)	Mammalia (哺乳類)
Order	Anthoathecata (花クラゲ目)	Carnivora (ネコ目)
Family	Hydridae	Ursidae (Bears)
Genus	Hydra	Ursus (Bears)
Species	Hydra vulgaris	Ursus maritimus

Evolutionary Relationship

common hydra and Polar bear share a common ancestor at the Kingdom level: Animalia. (動物)

表示 Kingdom: Animalia

Conservation Status

common hydra

NE — Not Evaluated

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	common hydra	Polar bear
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

common hydra

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, and Sweden.

Polar bear

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and boreal forests and taiga, among 4 distinct biome types within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found in Norway. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

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.

Polar bear

地球上で最大の陸上肉食動物であるホッキョクグマは700kgを超えることがあり、カナダからロシアまでの北極海氷域全体に分布する。ワモンアザラシとヒゲアザラシを狩るために海氷に依存する高度に特化した海洋哺乳類である。広大な距離を泳ぐことができる優れた泳者でもある。脆弱種に指定されており、気候変動による急激な北極海氷の消失で個体群が深刻な圧力を受けている。