Cephalorhynchus
Cephalorhynchus is a genus in the dolphin family Delphinidae.
| Cephalorhynchus | |
|---|---|
 | |
| Commerson's dolphin | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Infraorder: | Cetacea |
| Family: | Delphinidae |
| Subfamily: | Cephalorhynchinae |
| Genus: | Cephalorhynchus Gray, 1846 |
| Species | |
Extant species
It consists of four species:
| Image | Scientific name | Common name | Distribution |
|---|---|---|---|
| Commerson's dolphin | C. commersonii | Argentina including Puerto Deseado, in the Strait of Magellan and around Tierra del Fuego, and near the Falkland Islands, near the Kerguelen Islands in the southern part of the Indian Ocean | |
 | Chilean dolphin | C. eutropia | coast of Chile |
 | Heaviside's dolphin | C. heavisidii | coast of northern Namibia at 17°S and as far south as the southern tip of South Africa |
 | Hector's dolphin | C. hectori | coastal regions of New Zealand |
The species have similar physical features—they are small, generally playful, blunt-nosed dolphins—but they are found in distinct geographical locations.
A phylogenetic analysis by May-Collado & Agnarsson 2006 indicated the two species traditionally assigned to the genus Lagenorhynchus, the hourglass dolphin L. cruciger and Peale's dolphin L. australis are actually phylogenetically nested among the species of Cephalorhynchus, and they suggest these two species should be transferred to the genus Cephalorhynchus. Some acoustic and morphological data support this arrangement, at least with respect to Peale's dolphin.
According to Schevill & Watkins 1971, Peale's dolphin and the Cephalorhynchus species are the only dolphins that do not whistle (no acoustic data are available for the hourglass dolphin). Peale's dolphin also shares with several Cephalorhynchus species the possession of a distinct white "armpit" marking behind the pectoral fin.
References
- May-Collado, Laura; Agnarsson, Ingi (2006). "Cytochrome b and Bayesian inference of whale phylogeny" (PDF). Molecular Phylogenetics and Evolution. 38 (2): 344–54. doi:10.1016/j.ympev.2005.09.019. ISSN 1055-7903. OCLC 441745572. PMID 16325433. Retrieved 2 February 2013.
- Schevill, W.E.; Watkins, W.A. (15 January 1971). "Pulsed sounds of the porpoise Lagenorhynchus australis". Breviora. 366: 1–10. ISSN 0006-9698. OCLC 80876226.