common earthworm vs Polar bear

Lumbricus terrestris compared with Ursus maritimus

Key Differences

common earthworm is Not Evaluated while Polar bear is Vulnerable.

Taxonomic Classification

Rank	common earthworm	Polar bear
Kingdom same	Animalia (動物)	Animalia (動物)
Phylum	Annelida (環形動物)	Chordata (脊索動物)
Class	Clitellata (環帯類)	Mammalia (哺乳類)
Order	Crassiclitellata (Crassiclitellata)	Carnivora (ネコ目)
Family	Lumbricidae	Ursidae (Bears)
Genus	Lumbricus	Ursus (Bears)
Species	Lumbricus terrestris	Ursus maritimus

Evolutionary Relationship

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

表示 Kingdom: Animalia

Conservation Status

common earthworm

NE — Not Evaluated

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

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

Habitat & Geographic Range

common earthworm

Habitat

Native to Europe and North America, inhabiting ecosystems characteristic of the region.

Range

Found across Europe (6 countries) and North America (United States).

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 earthworm

Lumbricus terrestris, the common earthworm, is one of the most ecologically significant invertebrates in temperate soils and is native to Europe, with introduced populations established across North America and other regions globally. The species is not evaluated by the IUCN Red List. Lumbricus terrestris belongs to the family Lumbricidae and is widely distributed across Belgium, Denmark, Germany, Norway, Sweden, the United Kingdom, the United States, and other countries in its introduced range. It typically inhabits moist, organic-rich soils in gardens, agricultural fields, woodlands, and grasslands, burrowing deep into the substrate and surfacing at night or after rainfall to feed on decomposing leaf litter and soil organic matter. As a detritivore and ecosystem engineer, the common earthworm dramatically improves soil structure, aeration, drainage, and fertility through its burrowing activity and the production of nutrient-rich castings. It is a critical food source for a wide range of predators including birds, mammals, amphibians, and invertebrates. Charles Darwin extensively studied Lumbricus terrestris and recognized its profound role in soil formation and ecosystem functioning in his 1881 publication on the subject. 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。