Canadian beaver vs

Castor canadensis compared with Chrysococcus punctiformis

Taxonomic Classification

Rank	Canadian beaver
Kingdom	Animalia (Animals)	Chromista (Chromista)
Phylum	Chordata (Chordates)	Ochrophyta (Ochrophyta)
Class	Mammalia (Mammals)	Chrysophyceae (Chrysophyceae)
Order	Rodentia (Rodents)	Chromulinales (Chromulinales)
Family	Castoridae (Beavers)	Dinobryaceae
Genus	Castor (Beavers)	Chrysococcus
Species	Castor canadensis	Chrysococcus punctiformis

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, 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.

Chrysococcus punctiformis is a unicellular freshwater chrysophyte microalga in the genus Chrysococcus, class Chrysophyceae. The specific epithet punctiformis — meaning point-shaped or dot-like — likely references the diminutive size of this species relative to other Chrysococcus species, or alternatively describes a distinctive punctate surface pattern on the lorica visible under microscopy. In Chrysococcus, the lorica is the primary taxonomic structure, and its form, texture, and any ornamentation distinguish species from one another. C. punctiformis has been recorded from Norwegian and Swedish freshwater environments, extending also to Brazilian localities. This broad distribution spanning subarctic Scandinavian lakes and tropical or subtropical South American water bodies suggests either genuine cosmopolitan dispersal of this species through passive mechanisms, or convergent morphological evolution that has been misidentified as the same taxon in different regions. Molecular phylogenetic data would help resolve this question. The species inhabits the limnetic zone of freshwater systems, where it functions as a primary producer and component of the nanoplankton community. Chrysococcus species are characteristic members of oligotrophic lake phytoplankton in Scandinavia, often co-occurring with other chrysophytes, diatoms, and chlorophytes. C. punctiformis uses chlorophylls a and c along with fucoxanthin for photosynthesis and may practice mixotrophic nutrition. It has not been assessed under IUCN criteria and is listed as Not Evaluated.