cobweb spiders vs Polar bear

Latrodectus mactans compared with Ursus maritimus

Key Differences

cobweb spiders is Not Evaluated while Polar bear is Vulnerable.

Taxonomic Classification

Rank	cobweb spiders	Polar bear
Kingdom same	Animalia (動物)	Animalia (動物)
Phylum	Arthropoda (節足動物)	Chordata (脊索動物)
Class	Arachnida (クモガタ類)	Mammalia (哺乳類)
Order	Araneae (クモ目)	Carnivora (ネコ目)
Family	Theridiidae	Ursidae (Bears)
Genus	Latrodectus	Ursus (Bears)
Species	Latrodectus mactans	Ursus maritimus

Evolutionary Relationship

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

表示 Kingdom: Animalia

Conservation Status

cobweb spiders

NE — Not Evaluated

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

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

Habitat & Geographic Range

cobweb spiders

Habitat

Typically found in terrestrial habitats from forests to deserts.

Range

Widely distributed across Asia (Japan), Europe (8 countries), North America (United States), and South America (Ecuador).

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.

cobweb spiders

The southern black widow (Latrodectus mactans) is one of North America's most recognizable and medically significant spiders, a member of the genus Latrodectus within the family Theridiidae. Females are glossy black with the iconic red hourglass marking on the underside of the abdomen, and reach approximately 8–15 millimeters in body length; males are smaller, paler, and largely harmless. The species constructs irregular, low-lying cobwebs in dark, sheltered locations including woodpiles, outbuildings, hollow logs, rock piles, and debris, where it waits for prey—primarily insects—to blunder into the sticky tangle. Distribution spans the southeastern United States westward through Texas and northward into more temperate zones, with range overlap with related widow species. The venom of Latrodectus mactans contains alpha-latrotoxin, a potent neurotoxin that triggers massive release of neurotransmitters at synaptic junctions, causing the syndrome of latrodectism: severe muscle cramps, pain, hypertension, and autonomic disturbances. Despite its fearsome reputation, bites are rarely fatal in healthy adults when medical treatment is available. Females are cannibalistic toward males, though this behavior is less consistent in nature than laboratory conditions suggest. The species plays an important ecological role in controlling insect populations in arid and semi-arid habitats. Its conservation status has not been formally evaluated by the IUCN.

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。