vs Commerson s Dolphin

Cocconeis placentula compared with Cephalorhynchus commersonii

Key Differences

is Not Evaluated while Commerson s Dolphin is Least Concern.

Taxonomic Classification

Rank		Commerson s Dolphin
Kingdom	Chromista (크로미스타)	Animalia (동물)
Phylum	Ochrophyta (대롱편모조식물)	Chordata (척삭동물)
Class	Bacillariophyceae (원시배선규조류)	Mammalia (포유류)
Order	Achnanthales (Achnanthales)	Cetacea (Whales & Dolphins)
Family	Cocconeidaceae	Delphinidae (Oceanic Dolphins)
Genus	Cocconeis	Cephalorhynchus
Species	Cocconeis placentula	Cephalorhynchus commersonii

Conservation Status

NE — Not Evaluated

Commerson s Dolphin

LC — Least Concern

Physical Characteristics

Attribute		Commerson s Dolphin
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Habitat

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

Range

Distributed across Brazil, Norway, Portugal, Sweden, and Taiwan.

Commerson s Dolphin

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Cocconeis placentula is among the most ubiquitous and widely studied freshwater and brackish-water diatoms worldwide, serving as a model organism for periphyton ecology and a key species in biological assessment of water quality. A member of the family Cocconeidaceae, this adnate epiphyte produces a characteristic ovoid frustule with fine transapical striae, a well-developed raphe system on one valve, and an elaborate pattern of areolae visible under electron microscopy. The species complex encompasses several morphological varieties (var. placentula, var. lineata, var. euglypta, var. acuta) that differ in fine structural details of the valve ornamentation. Cocconeis placentula colonizes the surfaces of aquatic plants, algae, rocks, and sediment particles in rivers, lakes, and ponds across a vast global range spanning Europe, the Americas, Asia, Africa, and beyond, tolerating a wide range of water temperatures, pH values, and moderate nutrient enrichment. Its abundance varies dramatically with substrate type, light availability, and water chemistry, making community composition data involving this species valuable in diatom-based paleolimnological reconstructions and modern bioassessment indices. As a benthic primary producer, C. placentula contributes substantially to the productivity of the photic benthos and serves as a dietary component for invertebrate grazers. Its remarkable cosmopolitan distribution and ecological flexibility make it one of the defining species of freshwater periphyton communities globally. Conservation status is not formally assessed.

Commerson s Dolphin

<em>Cephalorhynchus commersonii</em>, commonly known as Commerson's Dolphin, is a small cetacean in the family Delphinidae. This species is classified as Least Concern on the IUCN Red List and is notable for its striking black-and-white coloration, which makes it one of the most visually distinctive dolphin species. Commerson's Dolphins typically inhabit coastal and nearshore marine environments of the Southern Hemisphere, particularly around the Falkland Islands, the southern tip of South America, and a geographically isolated population near the Kerguelen Islands in the Indian Ocean. These dolphins are highly social animals, often observed in small groups engaging in acrobatic behaviors near the surface. They typically feed on fish, squid, and crustaceans, often hunting cooperatively in shallow waters and kelp beds. Their average lifespan is approximately 18 years, and they are known for their fast, energetic swimming. Commerson's Dolphins are sometimes caught as bycatch in fishing nets, posing a localized conservation concern despite their overall Least Concern status.