Canadian beaver vs

Castor canadensis compared with Chrysococcus radians

Taxonomic Classification

Rank	Canadian beaver
Kingdom	Animalia (สัตว์)	Chromista (โครมิสตา)
Phylum	Chordata (สัตว์มีแกนสันหลัง)	Ochrophyta (Ochrophyta)
Class	Mammalia (สัตว์เลี้ยงลูกด้วยน้ำนม)	Chrysophyceae (สาหร่ายสีทอง)
Order	Rodentia (อันดับสัตว์ฟันแทะ)	Chromulinales (Chromulinales)
Family	Castoridae (Beavers)	Dinobryaceae
Genus	Castor (Beavers)	Chrysococcus
Species	Castor canadensis	Chrysococcus radians

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 and South America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Brazil, Denmark, 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.

Chrysococcus radians is a freshwater chrysophyte microalga in the genus Chrysococcus, class Chrysophyceae, order Chromulinales. The species epithet radians — radiating — describes a lorica with radiating spine-like projections or extensions emanating from the central body of the outer case, a morphological feature readily distinguishable under light microscopy. Radiating processes on chrysophyte loricas are thought to increase the effective surface area of the cell, potentially slowing sinking and maintaining the organism in the illuminated photic zone of freshwater lakes. C. radians has been documented from Norwegian and Swedish freshwater systems, with additional records from Denmark, consistent with a broader northern European distribution of this species. Scandinavian lakes, particularly the oligotrophic highland lakes of Norway and Sweden, harbor diverse chrysophyte communities in which Chrysococcus and related genera are frequently dominant components during spring and autumn mixing periods. The species inhabits the limnetic zone, where it engages in photosynthesis using the characteristic golden-brown chrysophyte pigments — chlorophylls a and c combined with fucoxanthin. Like other genus members, C. radians may also practice mixotrophic feeding on bacteria and dissolved organic matter, providing nutritional flexibility in oligotrophic environments. Siliceous stomatocysts produced by chrysophytes can survive in lake sediments and provide paleolimnological records of past environmental change. C. radians has not been evaluated under IUCN Red List criteria and is classified as Not Evaluated.