Caucasian Birch Mouse vs

Sicista caucasica compared with Chrysosphaerella annulata

Key Differences

• Caucasian Birch Mouse is Near Threatened while is Not Evaluated.

Taxonomic Classification

Rank	Caucasian Birch Mouse
Kingdom	Animalia (Animals)	Chromista (Chromista)
Phylum	Chordata (Chordates)	Ochrophyta (Ochrophyta)
Class	Mammalia (Mammals)	Chrysophyceae (Chrysophyceae)
Order	Rodentia (Rodents)	Ochromonadales (Ochromonadales)
Family	Dipodidae	Paraphysomonadaceae
Genus	Sicista	Chrysosphaerella
Species	Sicista caucasica	Chrysosphaerella annulata

Conservation Status

Caucasian Birch Mouse

NT — Near Threatened

NE — Not Evaluated

Physical Characteristics

Attribute	Caucasian Birch Mouse
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Caucasian Birch Mouse

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway and Sweden.

Caucasian Birch Mouse

The Caucasian Birch Mouse (Sicista caucasica) is a species in the genus Sicista. It is currently classified as Near Threatened on the IUCN Red List. Typically found in diverse terrestrial and aquatic ecosystems.

Chrysosphaerella annulata is a colonial freshwater chrysophyte microalga in the genus Chrysosphaerella, class Chrysophyceae. Unlike unicellular loricate chrysophytes, Chrysosphaerella species form spherical or ellipsoidal free-floating colonies in which individual cells are embedded in a common gelatinous matrix. The individual cells bear long siliceous scales with distinctive ring-like or annular structures — referenced by the species epithet annulata — projecting outward from the colony surface, giving the colony a spiny appearance under microscopy. These siliceous scales are species-specific and their morphology, as revealed through electron microscopy, is the primary character for identifying Chrysosphaerella species. C. annulata has been recorded from Norwegian and Swedish freshwater environments, consistent with the Scandinavian emphasis in chrysophyte research and the high diversity of chrysophytes in boreal freshwater systems. Chrysosphaerella colonies are planktonic, inhabiting the limnetic zone of oligotrophic to mesotrophic lakes where they may form locally conspicuous populations during favorable conditions. The species uses chlorophylls a and c with fucoxanthin for photosynthesis, contributing to primary production. Chrysosphaerella scales can accumulate in lake sediments, providing a record of past community composition and environmental conditions. C. annulata has not been assessed under IUCN criteria and is classified as Not Evaluated. Its documentation contributes to understanding the diversity of colonial chrysophyte forms in northern European freshwater ecosystems.