vs Common Metad

Chrysosphaerella annulata compared with Millardia meltada

Key Differences

• is Not Evaluated while Common Metad is Least Concern.

Taxonomic Classification

Rank		Common Metad
Kingdom	Chromista (Chromista)	Animalia (Animals)
Phylum	Ochrophyta (Ochrophyta)	Chordata (Chordates)
Class	Chrysophyceae (Chrysophyceae)	Mammalia (Mammals)
Order	Ochromonadales (Ochromonadales)	Rodentia (Rodents)
Family	Paraphysomonadaceae	Muridae (Mice & Rats)
Genus	Chrysosphaerella	Millardia
Species	Chrysosphaerella annulata	Millardia meltada

Conservation Status

NE — Not Evaluated

Common Metad

LC — Least Concern

Physical Characteristics

Attribute		Common Metad
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway and Sweden.

Common Metad

Habitat

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.

Common Metad

The Common Metad (<em>Millardia meltada</em>) is a rodent belonging to the genus <em>Millardia</em> within the family Muridae. As a member of the Old World rats and mice, this species is typically found in diverse terrestrial and aquatic ecosystems across its range. The Common Metad is classified as Least Concern on the IUCN Red List, indicating that its populations are currently stable and not facing immediate extinction risk. Detailed biological traits such as body length, weight, and lifespan have not been widely documented for this species in available records. Its taxonomy places it within the order Rodentia, which encompasses a broad array of gnawing mammals adapted to a wide variety of ecological niches. While specific dietary habits are not well characterized in the available data, members of the genus <em>Millardia</em> are generally understood to be omnivorous, feeding on plant material and invertebrates typical of their habitat. Ongoing monitoring is important for ensuring this species maintains its current conservation standing.