Canadian beaver vs

Castor canadensis compared with Comatricha nigra

Taxonomic Classification

Rank	Canadian beaver
Kingdom	Animalia (Animals)	Protozoa (protozoa)
Phylum	Chordata (Chordates)	Mycetozoa
Class	Mammalia (Mammals)	Myxomycetes (Myxomycetes)
Order	Rodentia (Rodents)	Stemonitidales
Family	Castoridae (Beavers)	Stemonitidaceae
Genus	Castor (Beavers)	Comatricha
Species	Castor canadensis	Comatricha nigra

Conservation Status

Canadian beaver

NE — Not Evaluated

Population: ~15.0M

Trend: Stable →

NE — Not Evaluated

Physical Characteristics

Attribute	Canadian beaver
Diet	Herbivore	—
Average Lifespan	15 years	—
Average Length	1.0 m	—
Average Weight	25.0 kg	—

Habitat & Geographic Range

Canadian beaver

Habitat

Typically found in grasslands, forests, and vegetated habitats.

Range

Widely distributed across Europe (15 countries), North America (United States), and South America (Argentina, Chile).

Habitat

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

Range

Widely distributed across Asia (Taiwan), Europe (Belgium, Norway, Sweden), North America (United States), and South America (Brazil).

Canadian beaver

The largest rodent in North America, Canadian beavers weigh up to 32 kg and are master ecosystem engineers inhabiting rivers, lakes, and wetlands across Canada and the northern United States. By felling trees and constructing dams up to hundreds of meters long, beavers create ponds that provide habitat for hundreds of species. Their lodges and canals transform entire watersheds. Once nearly hunted to extinction for their fur, beaver populations have recovered strongly.

<em>Comatricha nigra</em> is among the more widely distributed species in the genus <em>Comatricha</em>, with documented records from Asia, Europe, North America, and South America. It belongs to the class Myxomycetes, order Stemonitidales, and is recognized by its dark, stalked sporangia with a distinctive capillitium. The species grows on decaying wood, bark, and moist plant debris in forest habitats across its broad geographic range. As with all plasmodial slime molds, <em>C. nigra</em> undergoes a life cycle that includes a motile plasmodial feeding stage and a reproductive sporangial stage. The feeding plasmodium consumes bacteria, fungal spores, and organic particles, playing a role in nutrient cycling and decomposition. The global distribution of <em>C. nigra</em> reflects the capacity of slime mold spores to disperse over long distances via wind currents. No quantitative biological metrics are recorded, and the species has not been assessed by the IUCN.

Shared Countries

Both species can be found in 4 countries:

🇧🇪 Belgium 🇳🇴 Norway 🇸🇪 Sweden 🇺🇸 United States