Columbia River Signal Crayfish vs koala

Pacifastacus leniusculus compared with Phascolarctos cinereus

Key Differences

• Columbia River Signal Crayfish is Not Evaluated while koala is Vulnerable.

Taxonomic Classification

Rank	Columbia River Signal Crayfish	koala
Kingdom same	Animalia (动物界)	Animalia (动物界)
Phylum	Arthropoda (节肢动物门)	Chordata (脊索动物门)
Class	Malacostraca (软甲纲)	Mammalia (哺乳動物)
Order	Decapoda (十足目)	Diprotodontia (雙門齒目)
Family	Astacidae	Phascolarctidae (Koalas)
Genus	Pacifastacus	Phascolarctos (Koalas)
Species	Pacifastacus leniusculus	Phascolarctos cinereus

Evolutionary Relationship

Columbia River Signal Crayfish and koala share a common ancestor at the Kingdom level: Animalia. (动物界)

Conservation Status

Columbia River Signal Crayfish

NE — Not Evaluated

koala

VU — Vulnerable

Population: ~100.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Columbia River Signal Crayfish	koala
Diet	—	Herbivore
Average Lifespan	—	15 years
Average Length	—	75 cm
Average Weight	—	10.0 kg

Habitat & Geographic Range

Columbia River Signal Crayfish

Habitat

Typically found in marine, freshwater, and terrestrial environments.

Range

Widely distributed across Asia (Japan), Europe (26 countries), and North America (United States).

koala

Habitat

Typically found in grasslands, forests, and vegetated habitats.

Range

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

Columbia River Signal Crayfish

<em>Pacifastacus leniusculus</em>, the Columbia River signal crayfish, is a freshwater crustacean in the family Astacidae native to the Pacific Northwest of North America and widely introduced across Europe, Japan, and other regions. This species has not been evaluated by the IUCN but is recognised as one of the most ecologically damaging invasive freshwater species in Europe, present in 26 European countries, Japan, and its native range in the United States. Signal crayfish are large, aggressive, and highly fecund, capable of displacing native crayfish species through competition and through transmission of crayfish plague, a disease caused by the oomycete <em>Aphanomyces astaci</em>, to which North American crayfish have evolved resistance but European species have not. This species inhabits a wide range of freshwater environments including rivers, streams, lakes, and estuaries, as well as adjacent terrestrial habitats. Signal crayfish are omnivores, consuming aquatic plants, invertebrates, fish eggs, and organic detritus, and their burrowing activity can destabilise stream banks and increase turbidity. Management of invasive populations is a major focus of freshwater conservation in Europe. Biological traits of this species remain poorly documented in the scientific literature.

koala

澳大利亚东部和东南部的标志性有袋类动物，体重最大可达15千克，为了节省低热量桉树叶食物所提供的能量，每天最多睡眠22小时。高度特化，能够处理会致大多数其他哺乳动物死亡的有毒桉树成分，拥有专门适应解毒功能的肠道微生物群。因衣原体病、栖息地开发和气候变化导致种群锐减，2022年被列为濒危物种。