Clymene Dolphin vs Compact Stonewort

Stenella clymene compared with Nitella tenuissima

Key Differences

Clymene Dolphin is Least Concern while Compact Stonewort is Extinct.

Taxonomic Classification

Rank	Clymene Dolphin	Compact Stonewort
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Chordata (Chordates)	Charophyta (Charophyta)
Class	Mammalia (Mammals)	Charophyceae (Charophyceae)
Order	Cetacea (Whales & Dolphins)	Charales (Charales)
Family	Delphinidae (Oceanic Dolphins)	Characeae
Genus	Stenella	Nitella
Species	Stenella clymene	Nitella tenuissima

Conservation Status

Clymene Dolphin

LC — Least Concern

Compact Stonewort

EX — Extinct

Physical Characteristics

Attribute	Clymene Dolphin	Compact Stonewort
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Clymene Dolphin

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Distributed across Norway and Venezuela.

Compact Stonewort

Habitat

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

Range

Distributed across Brazil, Norway, Sweden, Taiwan, and United States.

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.

Compact Stonewort

<em>Nitella tenuissima</em>, a stonewort formerly found in fresh and brackish water habitats, was a member of the charophyte family Characeae — the algal lineage most closely related to land plants. Historical records document its occurrence across Brazil, Norway, Sweden, Taiwan, and the United States, where it inhabited clear, oligotrophic lakes, ponds, and slow-flowing water bodies with low nutrient levels. Like other Nitella species, it was a delicate, translucent, submerged aquatic plant lacking the calcium carbonate encrustation of related genera, forming low-growing mats on soft sediments in well-illuminated shallow water. The species played a role in aquatic ecosystems by stabilising lake sediments, contributing to water clarity, and providing microhabitat for invertebrates and small aquatic organisms. <em>Nitella tenuissima</em> is classified as Extinct by the IUCN, having not been recorded from any of its former localities despite targeted searches. The primary causes of its extinction are believed to be widespread eutrophication of freshwater habitats driven by agricultural nutrient runoff and sewage discharge, which eliminated the clear, nutrient-poor conditions on which the species depended. The loss of this stonewort is emblematic of the broader decline of freshwater charophyte diversity across the Northern Hemisphere. Biological traits including historical morphological measurements and reproductive parameters are documented only in sparse historical herbarium specimens and early botanical literature.