Arctic lemming vs

Dicrostonyx torquatus compared with Cocconeis disculus

Key Differences

• Arctic lemming is Least Concern while is Not Evaluated.

Taxonomic Classification

Rank	Arctic lemming
Kingdom	Animalia (Animals)	Chromista (Chromista)
Phylum	Chordata (Chordates)	Ochrophyta (Ochrophyta)
Class	Mammalia (Mammals)	Bacillariophyceae (Bacillariophyceae)
Order	Rodentia (Rodents)	Achnanthales (Achnanthales)
Family	Cricetidae	Cocconeidaceae
Genus	Dicrostonyx	Cocconeis
Species	Dicrostonyx torquatus	Cocconeis disculus

Conservation Status

Arctic lemming

LC — Least Concern

NE — Not Evaluated

Physical Characteristics

Attribute	Arctic lemming
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Arctic lemming

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Habitat

Native to Europe and South America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Brazil, Norway, and Sweden.

Arctic lemming

The Arctic lemming (Dicrostonyx torquatus) is a species in the genus Dicrostonyx. It is currently classified as Least Concern on the IUCN Red List. Typically found in diverse terrestrial and aquatic ecosystems.

Cocconeis disculus is a freshwater and brackish-water diatom in the family Cocconeidaceae, belonging to the class Bacillariophyceae—the diatoms, a group of unicellular photosynthetic algae encased in ornate silica cell walls called frustules. Like all members of the genus Cocconeis, C. disculus is an adnate, epiphytic species, meaning it lives attached to substrates—typically the surfaces of aquatic macrophytes, filamentous algae, and sediment particles—rather than living freely in the water column. The frustule of Cocconeis species is distinctive in its bilateral symmetry and the characteristic difference between its two valves: the rapheless valve (RV) lacks the raphe slit present on the raphe valve (RV), a feature used in species identification. Cocconeis disculus has been documented from freshwater bodies across South America and various parts of the Northern Hemisphere, with distribution reflecting its tolerance of a range of water temperatures and nutrient conditions. Diatoms like C. disculus are foundational components of aquatic food webs, fixing carbon through photosynthesis and providing a nutritious food source for grazing invertebrates, protists, and larval fish. The species also contributes to the biosilica cycle through the production and dissolution of its silica frustule. As a benthic, substrate-attached organism, Cocconeis disculus serves as a sensitive bioindicator of water quality conditions in freshwater monitoring programs. Its conservation status is not formally evaluated.