vs Common Fat-tailed Mouse Opossum

Chrysococcus radians compared with Thylamys pusillus

Key Differences

• is Not Evaluated while Common Fat-tailed Mouse Opossum is Least Concern.

Taxonomic Classification

Rank		Common Fat-tailed Mouse Opossum
Kingdom	Chromista (Chromista)	Animalia (Animals)
Phylum	Ochrophyta (Ochrophyta)	Chordata (Chordates)
Class	Chrysophyceae (Chrysophyceae)	Mammalia (Mammals)
Order	Chromulinales (Chromulinales)	Didelphimorphia (Didelphimorphia)
Family	Dinobryaceae	Didelphidae
Genus	Chrysococcus	Thylamys
Species	Chrysococcus radians	Thylamys pusillus

Conservation Status

NE — Not Evaluated

Common Fat-tailed Mouse Opossum

LC — Least Concern

Physical Characteristics

Attribute		Common Fat-tailed Mouse Opossum
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.

Common Fat-tailed Mouse Opossum

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

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.

Common Fat-tailed Mouse Opossum

The Common Fat-tailed Mouse Opossum (<em>Thylamys pusillus</em>) is a small marsupial belonging to the genus Thylamys within the family Didelphidae. Like other members of its genus, this species typically stores fat in its tail, which becomes swollen during periods of food abundance and is metabolised during leaner times, a physiological adaptation that provides energy reserves. <em>Thylamys pusillus</em> is generally found in diverse terrestrial and aquatic ecosystems, often in dry woodlands, scrublands, and grassland habitats of South America. The species is assessed as Least Concern on the IUCN Red List, indicating it is not currently considered at risk of extinction. Detailed geographic range data are not available in the current record, but members of this genus are typically distributed across parts of Argentina, Bolivia, Paraguay, and Uruguay. Biological traits including average lifespan, body dimensions, and specific dietary composition remain poorly documented in the scientific literature, though Thylamys species are generally considered omnivorous, often consuming insects, small vertebrates, and plant material.