vs Colombian Oldfield Mouse

Chrysococcus radians 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 radians	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 and South America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Brazil, Denmark, and Sweden.

Colombian Oldfield Mouse

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in Colombia.

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.

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.