Alston s Cotton Rat vs

Sigmodon alstoni compared with Chrysococcus punctiformis

Key Differences

• Alston s Cotton Rat is Least Concern while is Not Evaluated.

Taxonomic Classification

Rank	Alston s Cotton Rat
Kingdom	Animalia (Animals)	Chromista (Chromista)
Phylum	Chordata (Chordates)	Ochrophyta (Ochrophyta)
Class	Mammalia (Mammals)	Chrysophyceae (Chrysophyceae)
Order	Rodentia (Rodents)	Chromulinales (Chromulinales)
Family	Cricetidae	Dinobryaceae
Genus	Sigmodon	Chrysococcus
Species	Sigmodon alstoni	Chrysococcus punctiformis

Conservation Status

Alston s Cotton Rat

LC — Least Concern

NE — Not Evaluated

Physical Characteristics

Attribute	Alston s Cotton Rat
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Alston s Cotton Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Distributed across Colombia and Venezuela.

Habitat

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

Range

Distributed across Brazil, Norway, and Sweden.

Alston s Cotton Rat

The Alston s Cotton Rat (Sigmodon alstoni) is a species in the genus Sigmodon. It is currently classified as Least Concern on the IUCN Red List. Typically found in diverse terrestrial and aquatic ecosystems. Distributed across Colombia and Venezuela.

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.