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 (動物)	Animalia (動物)
Phylum	Arthropoda (節足動物)	Chordata (脊索動物)
Class	Malacostraca (軟甲綱)	Mammalia (哺乳類)
Order	Decapoda (十脚目)	Diprotodontia (カンガルー目)
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. (動物)

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

オーストラリア東部・南東部を代表する有袋類で、体重は最大15kgに達し、低カロリーのユーカリの葉食から得るエネルギーを節約するために1日最大22時間を睡眠に費やす。他の哺乳類の多くを死に至らしめる有毒なユーカリ成分を処理するために高度に特化しており、解毒に特別に適応した腸内微生物叢を持つ。クラミジア感染症、生息地の伐採、気候変動により個体数が激減し、2022年に絶滅危惧種に指定された。