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Lagenorhynchus
''Lagenorhynchus'' is a genus of oceanic dolphins in the infraorder Cetacea, presently containing six extant species. However, there is consistent molecular evidence that the genus is polyphyletic and several of the species are likely to be moved to other genera. In addition, the extinct species '' Lagenorhynchus harmatuki'' is also classified in this genus. Etymology The name ''Lagenorhynchus'' derives from the Greek ''lagenos'' meaning "bottle" and ''rhynchus'' meaning "beak". Indeed, the "bottle-nose" is a characteristic of this genus. However, the dolphins popularly called bottlenose dolphins belong in the genus '' Tursiops''. Taxonomy There is compelling phylogenetic molecular evidence that the genus ''Lagenorhynchus'' is polyphyletic, in that it currently contains several species that are not closely related. found that white-beaked and Atlantic white-sided dolphins are phylogenetically isolated within the Delphinidae, where they are believed to be rather basal m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dusky Dolphin
The dusky dolphin (''Lagenorhynchus obscurus'') is a small oceanic dolphin found in coastal waters of the Southern Hemisphere. It is most closely related to the Pacific white-sided dolphin. The dolphin's range is patchy, major populations occurring around South America, southwestern Africa, New Zealand, and several oceanic islands, with some sightings around southern Australia. It has a somewhat stocky body with a short beak and a curved dorsal fin and flippers. Like its closest relative, the dusky dolphin has a multi-coloured pigmentation of black, grey, and white. The species prefers cool currents and inshore waters. It lives in a fission–fusion society where groups change size based on social and environmental conditions. The dolphin feeds on several fish and squid species and has flexible hunting tactics, including daytime bait ball herding and nightime feeding in deep scattering layers. Mating is polygynandrous, and several males will chase after a single female, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlantic White-sided Dolphin
The Atlantic white-sided dolphin (''Lagenorhynchus acutus'') is a distinctively coloured dolphin found in the cool to temperate waters of the North Atlantic Ocean. Description The Atlantic white-sided dolphin is a relatively small dolphin. At birth, calves measure just over a meter long; adult males grow to about , and females to about , weighing between 180–230 kg (400- 510 lb) once fully grown. Females reach sexual maturity between the ages of 6 and 12 years, and males between 7 and 11 years old. The gestation period is 11 months and lactation lasts for about 18 months — both typical figures for dolphins. Atlantic white-sided dolphins are known to live for at least 17 years. The key distinguishing feature is the dolphin's coloration—a white to pale-yellow patch is found behind the dorsal fin on both sides of the body. The white-sided dolphin's color variations are unique amongst the standard hues of white, grey, black and blue seen on other pelagic cetaceans. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagenorhynchus Harmatuki
''Lagenorhynchus'' is a genus of oceanic dolphins in the infraorder Cetacea, presently containing six extant species. However, there is consistent molecular evidence that the genus is polyphyletic and several of the species are likely to be moved to other genera. In addition, the extinct species '' Lagenorhynchus harmatuki'' is also classified in this genus. Etymology The name ''Lagenorhynchus'' derives from the Greek ''lagenos'' meaning "bottle" and ''rhynchus'' meaning "beak". Indeed, the "bottle-nose" is a characteristic of this genus. However, the dolphins popularly called bottlenose dolphins belong in the genus ''Tursiops''. Taxonomy There is compelling phylogenetic molecular evidence that the genus ''Lagenorhynchus'' is polyphyletic, in that it currently contains several species that are not closely related. found that white-beaked and Atlantic white-sided dolphins are phylogenetically isolated within the Delphinidae, where they are believed to be rather basal me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific White-sided Dolphin
The Pacific white-sided dolphin (''Lagenorhynchus obliquidens''), also known as the hookfin porpoise, is an active dolphin found in the cool or temperate waters of the North Pacific Ocean. Taxonomy The Pacific white-sided dolphin was named by Smithsonian mammalogist Theodore Gill, Theodore Nicholas Gill in 1865. It is morphologically similar to the dusky dolphin, which is found in the South Pacific. Genetic analysis by Frank Cipriano suggests the two species diverged around two million years ago. Though traditionally placed in the genus ''Lagenorhynchus'', molecular phylogeny, molecular analyses indicate they are closer to dolphins of the genus ''Cephalorhynchus'', in the Lissodelphininae subfamily, than to both the Atlantic white-sided dolphin and the White-beaked dolphin. It has therefore been proposed to move the Pacific white-sided dolphin to the resurrected genus ''Sagmatias'' together with other southern hemisphere ''Lagenorhyncus'' species (hourglass dolphin, Dusky dolphin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White-beaked Dolphin
The white-beaked dolphin (''Lagenorhynchus albirostris'') is a marine mammal belonging to the family Delphinidae (oceanic dolphins) in the suborder Odontoceti (toothed whales). Taxonomy The species was first described by the British taxonomist John Edward Gray in 1846. Due to its relative abundance in European waters, it was among the first of the genus ''Lagenorhynchus'' (''lagenos'', Latin for "bottle" or "flask"; ''rhynchos'', "beak" or "snout") to be known to science. Its specific name, ''albirostris'', translates to "white beak", a reference to the color of the species' beak, a diagnostic (albeit variable) trait useful in identification. Description The white-beaked dolphin is a robust species of dolphin with a short beak. Adults can reach long and weigh . Calves are long at birth and probably weigh about . The upper body and flanks are dark grey with light grey patches, including a 'saddle' behind the dorsal fin, while the underside is light grey to almost white in colo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delphinidae
Oceanic dolphins or Delphinidae are a widely distributed family of dolphins that live in the sea. Close to forty extant species are recognised. They include several big species whose common names contain "whale" rather than "dolphin", such as the Globicephalinae (round-headed whales, which include the false killer whale and pilot whale). Delphinidae is a family within the superfamily Delphinoidea, which also includes the porpoises (Phocoenidae) and the Monodontidae ( beluga whale and narwhal). River dolphins are relatives of the Delphinoidea. Oceanic dolphins range in size from the and Maui's dolphin to the and orca, the largest known dolphin. Several species exhibit sexual dimorphism; the males are larger than females. They have streamlined muscular bodies and two limbs that are modified into flippers. Though not quite as flexible as seals, some dolphins can travel at speeds 29 km/h (18 mph) for short distances. Most delphinids primarily eat fish, along with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hourglass Dolphin
The hourglass dolphin (''Lagenorhynchus cruciger'') is a small dolphin in the family Delphinidae that inhabits offshore Antarctic and sub-Antarctic waters. It is commonly seen from ships crossing the Drake Passage but has a circumpolar distribution. The species was identified as a new species by Jean René Constant Quoy and Joseph Paul Gaimard in 1824 from a drawing made in the South Pacific in 1820. It is the only cetacean to have been widely accepted as a species solely on witness accounts. Description The hourglass dolphin is colored black on top and white on the belly, with white patches on the sides and sometimes variations of dark grey. For this reason, it was colloquially known by whalers as a "sea cow" (although it does not belong to the taxonomic order Sirenia) or "sea skunk". Each flank has a white patch at the front, above the beak, eye and flipper, and a second patch at the rear. These two patches are connected by a thin white strip, creating, loosely speaking, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peale's Dolphin
Peale's dolphin (''Lagenorhynchus australis'') is a small dolphin found in the waters around Tierra del Fuego at the foot of South America. It is also commonly known as the black-chinned dolphin or even Peale's black-chinned dolphin. However, since Rice's work Peale's dolphin has been adopted as the standard common name. Taxonomy Though it is traditionally placed in the genus ''Lagenorhynchus'', recent molecular analyses indicate Peale's dolphin is actually more closely related to the dolphins of the genus '' Cephalorhynchus''. If true, this would mean this species must either be transferred to ''Cephalorhynchus'' or be given a new genus of its own. An alternate genus proposed for this species (as well as the Pacific white-sided dolphin, hourglass dolphin and dusky dolphin is the resurrected genus '' Sagmatias''. Some behavioral and morphological data support moving Peale's dolphin to ''Cephalorhynchus''. According to , Peale's dolphin and the ''Cephalorhynchus'' species are t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sagmatias
''Sagmatias'' was a genus of dolphins, defined in 1866 by Edward Drinker Cope with Peale's dolphin as type species, described as ''Sagmatias amblodon''. It has been proposed to resurrect the genus to include four species of oceanic dolphins currently classified in the genus ''Lagenorhynchus''. Mitochondrial DNA studies have indicated that Pacific white-sided dolphin, Peale's dolphin, dusky dolphin and hourglass dolphin are more closely related to dolphins in the Lissodelphininae subfamily, than to the two other members of the genus: Atlantic white-sided dolphin and white-beaked dolphin. This phylogenetic relationship is further supported by cladistic analysis of morphological characters. However, resurrection of the genus ''Sagmatias'' has not been accepted by the Society for Marine Mammalogy's taxonomic Committee, because the finer details of the phylogenetic relationships between the four species in the proposed ''Sagmatias'' genus and the four species of dolphins in the genus '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
