Brown Rat vs

Rattus norvegicus compared with Chrysosphaerella annulata

Key Differences

Brown Rat is Least Concern while is Not Evaluated.

Taxonomic Classification

Rank	Brown Rat
Kingdom	Animalia (動物)	Chromista (クロミスタ)
Phylum	Chordata (脊索動物)	Ochrophyta (オクロ植物)
Class	Mammalia (哺乳類)	Chrysophyceae (黄金色藻)
Order	Rodentia (ネズミ目)	Ochromonadales (Ochromonadales)
Family	Muridae (Mice & Rats)	Paraphysomonadaceae
Genus	Rattus	Chrysosphaerella
Species	Rattus norvegicus	Chrysosphaerella annulata

Conservation Status

Brown Rat

LC — Least Concern

NE — Not Evaluated

Physical Characteristics

Attribute	Brown Rat
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Brown Rat

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical grasslands and savannas, among 10 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (11 countries), Asia (15 countries), Europe (41 countries), North America (16 countries), Oceania and the Pacific (10 countries), and South America (10 countries).

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway and Sweden.

Brown Rat

ドブネズミ（Rattus norvegicus）はIUCNレッドリストで軽度懸念（LC）に分類されています。分布域全体に広く生息し個体数は安定しており、緊急の保護上の懸念はありません。

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.