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 (สัตว์)	Animalia (สัตว์)
Phylum	Arthropoda (สัตว์ขาปล้อง)	Chordata (สัตว์มีแกนสันหลัง)
Class	Malacostraca (Crustaceans)	Mammalia (สัตว์เลี้ยงลูกด้วยน้ำนม)
Order	Decapoda (Decapoda)	Diprotodontia (Marsupials)
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. (สัตว์)

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

Iconic marsupial of eastern and southeastern Australia, koalas weigh up to 15 kg and spend up to 22 hours daily sleeping to conserve energy from their low-calorie eucalyptus leaf diet. Highly specialized to process toxic eucalyptus compounds that would kill most other mammals, they have gut microbiomes uniquely adapted for detoxification. Listed as Endangered in 2022, with populations decimated by chlamydia disease, habitat clearing, and climate change.