vs Polar bear

Cocconeis disculus compared with Ursus maritimus

Key Differences

is Not Evaluated while Polar bear is Vulnerable.

Taxonomic Classification

Rank		Polar bear
Kingdom	Chromista (Chromista)	Animalia (Animals)
Phylum	Ochrophyta (Ochrophyta)	Chordata (Chordates)
Class	Bacillariophyceae (Bacillariophyceae)	Mammalia (Mammals)
Order	Achnanthales (Achnanthales)	Carnivora (Carnivorans)
Family	Cocconeidaceae	Ursidae (Bears)
Genus	Cocconeis	Ursus (Bears)
Species	Cocconeis disculus	Ursus maritimus

Conservation Status

NE — Not Evaluated

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute		Polar bear
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

Habitat

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

Range

Distributed across Brazil, Norway, and Sweden.

Polar bear

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and boreal forests and taiga, among 4 distinct biome types within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found in Norway. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

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.

Polar bear

The largest land carnivore on Earth, polar bears can exceed 700 kg and are found across Arctic sea ice from Canada to Russia. Highly specialized marine mammals that rely on sea ice to hunt ringed and bearded seals. Excellent swimmers capable of covering vast distances in open water. Listed as Vulnerable, with populations under severe pressure from rapid Arctic sea ice loss due to climate change.