vs Common Fat-tailed Mouse Opossum

Chroococcus minutus 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	Bacteria (Bacteria)	Animalia (Animals)
Phylum	Cyanobacteria (Cyanobacteria)	Chordata (Chordates)
Class	Cyanobacteriia	Mammalia (Mammals)
Order	Cyanobacteriales	Didelphimorphia (Didelphimorphia)
Family	Microcystaceae	Didelphidae
Genus	Chroococcus	Thylamys
Species	Chroococcus minutus	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, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, and Sweden.

Common Fat-tailed Mouse Opossum

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Chroococcus minutus is a cyanobacterium in the family Chroococcaceae, recognized as one of the smaller species in the genus. It is distributed in freshwater habitats across temperate regions, including Scandinavia and northern Europe, where it has been documented in taxonomic surveys of freshwater algae and cyanobacteria. Chroococcus species in general are characterized by their simple morphology — spherical or hemispherical cells, binary fission, and organization into pairs or tetrads within gelatinous sheaths. Chroococcus minutus occurs in the plankton and periphyton of lakes, ponds, and slowly flowing waters with low to moderate nutrient levels. Cyanobacteria of this type play roles in primary production and, in certain metabolically active strains, may contribute to nitrogen fixation in nitrogen-limited aquatic systems. The taxonomy of small-celled Chroococcus species remains challenging, with morphological overlap between species and significant variation in cell size related to environmental conditions and growth stage. Recent molecular studies have revealed that morphologically defined genera such as Chroococcus represent multiple phylogenetic lineages, indicating likely future taxonomic rearrangements. The species is not assessed by the IUCN.

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.