Cimar Round Ray vs Clymene Dolphin

Urotrygon cimar compared with Stenella clymene

Key Differences

• Cimar Round Ray is Near Threatened while Clymene Dolphin is Least Concern.

Taxonomic Classification

Rank	Cimar Round Ray	Clymene Dolphin
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Elasmobranchii	Mammalia (Mammals)
Order	Myliobatiformes (Myliobatiformes)	Cetacea (Whales & Dolphins)
Family	Urotrygonidae	Delphinidae (Oceanic Dolphins)
Genus	Urotrygon	Stenella
Species	Urotrygon cimar	Stenella clymene

Evolutionary Relationship

Cimar Round Ray and Clymene Dolphin share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Cimar Round Ray

NT — Near Threatened

Clymene Dolphin

LC — Least Concern

Physical Characteristics

Attribute	Cimar Round Ray	Clymene Dolphin
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cimar Round Ray

Clymene Dolphin

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Distributed across Norway and Venezuela.

Cimar Round Ray

The Cimar round ray (Urotrygon cimar) is a small stingray in the family Urotrygonidae, found in the eastern Pacific Ocean along the coasts of Central America and northern South America, including the waters of Costa Rica, Panama, Colombia, and Ecuador. It inhabits shallow coastal and estuarine waters over sandy and muddy bottoms, typically at depths of less than 50 meters, where it feeds on small benthic invertebrates and fish. Like other round rays in the genus Urotrygon, it has a nearly circular disc outline, a relatively slender tail, and a venomous caudal spine used defensively against predators. The species is classified as Near Threatened by the IUCN, reflecting its restricted range, vulnerability to coastal habitat degradation, and incidental capture in artisanal and commercial fisheries throughout its range. Bycatch in shrimp trawls and gill nets represents a significant ongoing threat to Urotrygon species throughout the eastern Pacific. Shallow coastal habitats in Central America and Colombia face continued pressure from development, mangrove loss, and pollution. The species' reproductive biology, like that of most Urotrygon rays, involves ovoviviparity, with females giving birth to live young after internal development. Population assessments for this species remain limited, and more data on abundance and mortality rates are needed.

Clymene Dolphin

The Clymene dolphin, Stenella clymene, is a small cetacean endemic to the tropical and subtropical waters of the Atlantic Ocean, ranging from the Gulf of Mexico and Caribbean Sea south along both the western and eastern Atlantic margins to approximately 20 degrees south latitude. Often called the short-snouted spinner dolphin, it is the only known naturally occurring cetacean hybrid species, believed to have originated through hybridization between the spinner dolphin (S. longirostris) and the striped dolphin (S. coeruleoalba). Clymene dolphins are acrobatic and frequently perform spinning leaps similar to but less elaborate than their spinner relatives. They travel in schools typically ranging from 10 to several hundred individuals, sometimes associating with other dolphin species. The species inhabits deep offshore pelagic waters and is rarely observed close to coastlines. It feeds primarily on fish and cephalopods, foraging at night when mesopelagic prey move into shallower waters. Clymene dolphins measure approximately 1.7–2 meters in length and display a distinctive tripartite pattern of dark cape, lighter grey flanks, and white or pale yellow belly. The species is assessed as Least Concern by the IUCN due to its relatively wide range and no evidence of major population-level threats.