vs Colombian Oldfield Mouse

Chrysococcus bisetus compared with Thomasomys dispar

Key Differences

• is Not Evaluated while Colombian Oldfield Mouse is Data Deficient.

Taxonomic Classification

Rank		Colombian Oldfield Mouse
Kingdom	Chromista (Chromista)	Animalia (Animals)
Phylum	Ochrophyta (Ochrophyta)	Chordata (Chordates)
Class	Chrysophyceae (Chrysophyceae)	Mammalia (Mammals)
Order	Chromulinales (Chromulinales)	Rodentia (Rodents)
Family	Dinobryaceae	Cricetidae
Genus	Chrysococcus	Thomasomys
Species	Chrysococcus bisetus	Thomasomys dispar

Conservation Status

NE — Not Evaluated

Colombian Oldfield Mouse

DD — Data Deficient

Physical Characteristics

Attribute		Colombian Oldfield Mouse
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway and Sweden.

Colombian Oldfield Mouse

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in Colombia.

Chrysococcus bisetus is a species of unicellular chrysophyte microalga in the genus Chrysococcus, class Chrysophyceae, order Chromulinales. The genus Chrysococcus is characterized by cells enclosed within a lorica — a secreted outer case or vesicle — through which flagella protrude, a structure that distinguishes it from many other chrysophytes. The epithet bisetus, meaning two-bristled, describes a diagnostic feature of the lorica, which bears two bristle-like projections used for species identification. Chrysococcus species inhabit freshwater and brackish environments, typically occurring in cool, nutrient-poor to moderately enriched lakes, ponds, and slow-flowing water bodies. C. bisetus has been recorded from Norwegian and Swedish waters, consistent with the historical focus of chrysophyte research in Scandinavian freshwater habitats, and also from Brazilian waters, suggesting a broader distribution. Chrysophytes including Chrysococcus species are important components of oligotrophic lake phytoplankton, where they contribute to primary production and serve as food for zooplankton. The golden-brown coloration of Chrysococcus arises from chlorophylls a and c together with fucoxanthin, pigments shared with other heterokonts. Unlike diatoms, chrysophytes produce chrysolaminarin as their storage carbohydrate rather than starch. C. bisetus has not been assessed under IUCN criteria and is listed as Not Evaluated. As with most freshwater microalgae, global population size and distribution are poorly characterized, limiting meaningful conservation assessment.

Colombian Oldfield Mouse

<em>Thomasomys dispar</em>, commonly known as the Colombian Oldfield Mouse, is a small rodent species belonging to the genus <em>Thomasomys</em> within the family Cricetidae. This species is classified as Data Deficient, indicating that insufficient information is currently available to evaluate its conservation status with confidence. It has been documented in Colombia, where it inhabits diverse terrestrial and aquatic-adjacent environments. Members of the genus <em>Thomasomys</em> are typically associated with high-altitude Andean habitats, including páramo grasslands, shrublands, and montane forest edges, where they occupy ground-level microhabitats and burrow in soft soils. These mice are generally omnivorous, consuming seeds, plant material, and invertebrates, though specific dietary data for <em>Thomasomys dispar</em> have not been recorded. Biological traits of this species remain poorly documented in the scientific literature. The Data Deficient classification highlights the need for targeted surveys in Colombian Andean regions to determine population size, distribution, and the ecological requirements of this poorly known rodent.