Black and white dolphins
| Black and white dolphins | ||||||||||||
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Hector's Dolphin ( Cephalorhynchus hectori ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Cephalorhynchus | ||||||||||||
| Gray , 1846 |
The black and white dolphins ( Cephalorhynchus ) are a genus of small dolphins in the cold seas of the southern hemisphere .
features
The black and white dolphins include the smallest whales - the length of the head is between 110 and 180 cm, the weight between 26 and 86 kg. What they all have in common is the color pattern of black and white areas that are clearly delimited from each other. In all species the head, fins and tail are black and the belly white; on the rest of the body the color distribution varies from species to species. The snout is blunt, a "beak" is missing.
Way of life
Like all dolphins, black and white dolphins live in schools. These consist of two to eight, sometimes over twenty animals. They live near the coast and like to swim in the wake of boats, but hardly ever jump. In contrast to other dolphins, black-and-white dolphins feed to a large extent on bottom -dwelling invertebrates , but also, typical of dolphins, on fish.
Systematics
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Phylogenetic systematics of the Delphinidae according to Horreo 2018
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Genetic studies show the black and white dolphins as a sister group to the short -snouted dolphins ( Lagenorhynchus ) and the great killer whale ( Orcinus orca ) is considered to be the sister species of these two genera . Together, these species are the subfamily Globicephalinae with the pilot whales ( Globicephala ), the pygmy killer whale ( Feresa attenuata ) and the Breitschnabel dolphin ( Peponocephala Electra ), the little Orca ( Pseudorca crassidens ) and the Risso ( Grampus griseus ) and the two species of the genus Orcaella faced .
The types are:
- Commerson's Dolphin ( Cephalorhynchus commersonii ), cold and temperate seas of South America and the adjacent sub-Antarctic
- White-bellied dolphin ( Cephalorhynchus eutropia ), Chilean coastal waters
- Heaviside dolphin ( Cephalorhynchus heavisidii ), coastal waters of southwestern Africa
- Hector's Dolphin ( Cephalorhynchus hectori ), New Zealand coastal waters
supporting documents
- ↑ a b c José L. Horreo: New insights into the phylogenetic relationships among the oceanic dolphins (Cetacea: Delphinidae). Journal of Zoological Systematics and Evolutionary Research 57 (2), May 2019; Pp. 476-480. doi : 10.1111 / jzs.12255
literature
- Ronald M. Nowak: Walker's Mammals of the World . Johns Hopkins University Press, 1999 ISBN 0-8018-5789-9
