vs Common Fat-tailed Mouse Opossum

Chrysococcus rufescens 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 rufescens	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, Norway, and Sweden.

Common Fat-tailed Mouse Opossum

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Chrysococcus rufescens is a loricate chrysophyte alga in the genus Chrysococcus. The specific epithet rufescens (Latin: reddish or becoming reddish) likely refers to a brownish-golden coloration of the lorica or the pigmented cell contents visible under light microscopy, reflecting the characteristic golden-brown color imparted by fucoxanthin and related carotenoids in chrysophyte chloroplasts. The lorica of C. rufescens encloses the cell and has an apical opening through which the flagellum extends. The species inhabits freshwater environments in northern Europe, including lakes and ponds in Scandinavia. Golden algae (chrysophytes) are typically most abundant in oligotrophic, cold, and poorly buffered waters, making them sensitive indicators of environmental change. C. rufescens contributes to primary production and the microbial food web as a mixotrophic nanoplankton organism capable of both photosynthesis and bacterivory. Chrysophyte loricas are preserved in lake sediments as stomatocysts and scale assemblages, providing long-term paleoecological records. The species has not been evaluated for conservation status by the IUCN and is categorized as Not Evaluated. Accurate identification of C. rufescens requires electron microscopy of lorica ultrastructure.

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.