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Orcaella
The snubfin dolphins (''Orcaella'') are a genus of cetaceans containing two members: the Irrawaddy dolphin (''Orcaella brevirostris'') and the Australian snubfin dolphin (''Orcaella heinsohni''). The genus was long believed to be monotypic with the only species being the Irrawaddy dolphin; however, in 2005, supposed Irrawaddy dolphin populations inhabiting the Australian/New Guinean regions were found to be significantly different and were declared a separate new species named the Australian snubfin dolphin. Taxonomy and evolution Until 2005, '' Orcaella brevirostris'' was the only recognized species in the genus ''Orcaella''. However, comparisons within the populations of ''Orcaella'' inhabiting the Asia region and populations inhabiting the Australia/New Guinea region show distinctions in habitat, morphology, and genetics.Ross, G. J. (2006). Review of the conservation status of Australia's smaller whales and dolphins. Department of the Environment and Water Resources. Morphologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irrawaddy Dolphin
The Irrawaddy dolphin (''Orcaella brevirostris'') is a euryhaline species of oceanic dolphin found in scattered subpopulations near sea coasts and in estuaries and rivers in parts of the Bay of Bengal and Southeast Asia. It closely resembles the Australian snubfin dolphin (of the same genus, '' Orcaella''), which was not described as a separate species until 2005. It has a slate blue to a slate gray color. Although found in much of the riverine and marine zones of South and Southeast Asia, the only concentrated lagoon populations are found in Chilika Lake in Odisha, India and Songkhla Lake in southern Thailand. Taxonomy One of the earliest recorded descriptions of the Irrawaddy dolphin was by Sir Richard Owen in 1866 based on a specimen found in 1852, in the harbour of Visakhapatnam on the east coast of India. It is one of two species in its genus. It has sometimes been listed variously in a family containing just itself and in the Monodontidae and Delphinidae. Widespread agre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orcaella Heinsohni
The Australian snubfin dolphin (''Orcaella heinsohni'') is a dolphin found off the northern coasts of Australia. It closely resembles the Irrawaddy dolphin (of the same genus, ''Orcaella'') and was not described as a separate species until 2005. The closest relative to the genus ''Orcaella'' is the killer whale, ''Orcinus orca''. The Australian snubfin has three colors on its skin, while the Irrawaddy dolphin only has two. The skull and the fins also show minor differences between the two species. Taxonomy The taxonomic specific name, ''heinsohni'', was chosen in honour of George Heinsohn, an Australian biologist who worked at James Cook University, "for his pioneering work on northeast Australian odontocetes, including the collection and initial analysis of ''Orcaella heinsohni'' specimens which form the basis for much of our knowledge of the new species". New species of large mammals are quite rarely described nowadays, and those that are usually are from remote areas ... [...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] |
Globicephalinae
Globicephalinae is a subfamily of oceanic dolphins that includes the pilot whales (''Globicephala'' spp.), the pygmy killer whale (''Feresa attenuata''), the rough-toothed dolphin (''Steno bredanensis''), the false killer whale (''Pseudorca crassidens''), the melon-headed whale (''Peponocephala electra''), Risso's dolphin Risso's dolphin (''Grampus griseus'') is a marine mammal and dolphin, the only species of the genus ''Grampus''. Some of the most closely related species to these dolphins include: pilot whales (''Globicephala'' spp.), pygmy killer whales (''Fere ... (''Grampus griseus''), and the snubfin dolphins ('' Orcaella'' spp.). References Oceanic dolphins {{Whale-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orca
The orca (''Orcinus orca''), or killer whale, is a toothed whale and the largest member of the oceanic dolphin family. The only extant species in the genus '' Orcinus'', it is recognizable by its black-and-white-patterned body. A cosmopolitan species, it inhabits a wide range of marine environments, from Arctic to Antarctic regions to tropical seas. Orcas are apex predators with a diverse diet. Individual populations often specialize in particular types of prey, including fish, sharks, rays, and marine mammals such as seals, dolphins, and whales. They are highly social, with some populations forming stable matrilineal family groups (pods). Their sophisticated hunting techniques and vocal behaviors, often unique to specific groups and passed down from generation to generation, are considered to be manifestations of animal culture. The International Union for Conservation of Nature (IUCN) lists the orca's conservation status as data deficient as multiple orca types ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN
The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status of the natural world and the measures needed to safeguard it. It is involved in data gathering and Data analysis, analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through buildin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gulf Of Carpentaria
The Gulf of Carpentaria is a sea off the northern coast of Australia. It is enclosed on three sides by northern Australia and bounded on the north by the eastern Arafura Sea, which separates Australia and New Guinea. The northern boundary is generally defined as a line from Slade Point, Queensland (the northwestern corner of Cape York Peninsula) in the northeast, to Cape Arnhem on the Gove Peninsula, Northern Territory (the easternmost point of Arnhem Land), in the west. At its mouth, the Gulf is wide, and further south, . The north-south length exceeds . It covers a water area of about . The general depth is between with a maximum depth of . The tidal range in the Gulf of Carpentaria is between . The Gulf and adjacent Sahul Shelf were dry land at the peak of the last ice age 18,000 years ago when global sea level was around below its present position. At that time a large, shallow lake occupied the centre of what is now the Gulf. The Gulf hosts a submerged coral reef p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogeny
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tree. History The theoretical framew ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
