vs Common Fat-tailed Mouse Opossum

Chrysococcus cordiformis 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 cordiformis	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.

Chrysococcus cordiformis is a freshwater chrysophyte microalga in the genus Chrysococcus, class Chrysophyceae. The species epithet cordiformis — heart-shaped — describes the characteristic lorica shape of this species, a lorica being the rigid or semi-rigid outer case secreted by the cell that gives Chrysococcus its distinctive appearance. The heart-shaped lorica of C. cordiformis provides a clear morphological character distinguishing it from species with spherical, ovoid, or otherwise shaped loricas. Chrysococcus species are unicellular, loricate golden algae that inhabit freshwater ecosystems, particularly the euphotic zones of oligotrophic to mesotrophic lakes and ponds. C. cordiformis has been documented from Norwegian and Swedish freshwater environments, which provide cold, clear-water habitats typical of Scandinavian highland and boreal lakes. Records also extend to Brazil, indicating a wide geographic range consistent with the passive dispersal capacity of small, light-weight planktonic microalgae. The cells of C. cordiformis possess one or two flagella that protrude through an opening in the lorica, enabling active swimming in the water column. Photosynthesis is conducted using chlorophylls a and c with carotenoid accessory pigments. Chrysococcus species may also feed phagotrophically on bacteria. C. cordiformis has not been formally evaluated under IUCN criteria and retains a conservation status of Not Evaluated. It represents a characteristic member of freshwater chrysophyte communities associated with cool, acidic, or nutrient-poor Scandinavian lake systems.

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.