Canadian beaver vs

Castor canadensis compared with Chrysosphaerella coronacircumspina

Taxonomic Classification

Rank	Canadian beaver
Kingdom	Animalia (Animals)	Chromista (Chromista)
Phylum	Chordata (Chordates)	Ochrophyta (Ochrophyta)
Class	Mammalia (Mammals)	Chrysophyceae (Chrysophyceae)
Order	Rodentia (Rodents)	Ochromonadales (Ochromonadales)
Family	Castoridae (Beavers)	Paraphysomonadaceae
Genus	Castor (Beavers)	Chrysosphaerella
Species	Castor canadensis	Chrysosphaerella coronacircumspina

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 Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway and Sweden.

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.

Chrysosphaerella coronacircumspina is a colonial chrysophyte alga in the genus Chrysosphaerella, family Chromulinaceae. Its compound specific epithet corona-circumspina (Latin: crown of surrounding spines) references the distinctive arrangement of silica spines forming a ring or crown around each cell in the colony. Each cell in a Chrysosphaerella colony bears both flat siliceous scales and long, projecting spines, with the spine arrangement being species-specific and taxonomically diagnostic. The colonial organization is held together by organic matrix material, creating a spherical or semi-spherical aggregate visible under light microscopy. C. coronacircumspina is found in freshwater phytoplankton communities in Scandinavia, consistent with the broader distribution of Chrysosphaerella in cold-temperate and subarctic lakes. The silica structures produced by Chrysosphaerella cells are deposited in lake sediments upon cell death, creating millennial-scale paleoenvironmental archives. Chrysophytes are sensitive to lake acidification, nutrients, and temperature, making them useful climate proxies in paleolimnological research. The species has not been assessed for conservation status by the IUCN and is listed as Not Evaluated.