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Melon-headed Whale
The melon-headed whale (''Peponocephala electra''), also known less commonly as the electra dolphin, little killer whale, or many-toothed blackfish, is a toothed whale of the oceanic dolphin family (Delphinidae). The common name is derived from the head shape. Melon-headed whales are widely distributed throughout deep tropical and subtropical waters worldwide, but they are rarely encountered at sea. They are found near shore mostly around oceanic islands, such as Hawaii, French Polynesia, and the Philippines. Taxonomy The melon-headed whale is the only member of the genus ''Peponocephala''. First recorded from a specimen collected in Hawaiʻi in 1841, the species was originally described as a member of the dolphin family and named ''Lagenorhynchus electra'' by John Edward Gray in 1846. The melon-headed whale was later determined to be sufficiently distinct from other ''Lagenorhynchus'' species to be accorded its own genus. A member of the subfamily Globicephalinae, melon-headed w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Edward Gray
John Edward Gray (12 February 1800 – 7 March 1875) was a British zoologist. He was the elder brother of zoologist George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray (1766–1828). The same is used for a zoological name. Gray was keeper of zoology at the British Museum in London from 1840 until Christmas 1874, before the natural history holdings were split off to the Natural History Museum. He published several catalogues of the museum collections that included comprehensive discussions of animal groups and descriptions of new species. He improved the zoological collections to make them amongst the best in the world. Biography Gray was born in Walsall, but his family soon moved to London, where Gray studied medicine. He assisted his father in writing ''The Natural Arrangement of British Plants'' (1821). After being blackballed by the Linnean Society of London, Gray shifted his interest from botany to zoology. He began his zoological ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
40th Parallel North
Following are circles of latitude between the 35th parallel north and the 40th parallel north: 36th parallel north The 36th parallel north is a circle of latitude that is 36 degrees north of the Earth's equatorial plane. It crosses Africa, the Mediterranean Sea, Asia, the Pacific Ocean, North America and the Atlantic Ocean. In the ancient Mediterranean world, its role for navigation and geography was similar to that played by the Equator today. From 7 April 1991 to 31 December 1996, the parallel defined the limit of the northern no-fly zone in Iraq. At this latitude the sun is visible for 14 hours, 36 minutes during the summer solstice and 9 hours, 43 minutes during the winter solstice. United States In the United States, the 36th parallel north is occasionally used as a rough northern boundary for the Sun Belt, a region spanning most Southern and Southwestern states and comprising most of the nation's warmest climates. Cities and landmarks close to the parallel inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rough-toothed Dolphin
The rough-toothed dolphin (''Steno bredanensis'') is a species of dolphin that can be found in deep warm and tropical waters around the world. The species was first described by Georges Cuvier in 1823. The genus name ''Steno'', of which this species is the only member, comes from the Greek for 'narrow', referring to the animal's beak — which is a diagnostic characteristic of the species. The specific name honours van Breda, who studied Cuvier's writings. There are no recognised subspecies. Taxonomy This species was formerly classified in the now-defunct subfamily Stenoninae, but more recent evidence has found that, despite its prominent bill, it in fact belongs with the blunt-nosed dolphins in the subfamily Globicephalinae. Description The rough-toothed dolphin is a relatively large species, with adults ranging from in length, and weighing between ; males are larger than females. Its most visible characteristic feature is its conical head and slender nose; other do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bottlenose Dolphin
The bottlenose dolphin is a toothed whale in the genus ''Tursiops''. They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus contains three species: the common bottlenose dolphin (''Tursiops truncatus''), the Indo-Pacific bottlenose dolphin (''Tursiops aduncus''), and Tamanend's bottlenose dolphin (''Tursiops erebennus''). Others, like the Burrunan dolphin (''Tursiops (aduncus) australis''), may be alternately considered their own species or be subspecies of ''T. aduncus''. Bottlenose dolphins inhabit warm and temperate seas worldwide, being found everywhere except for the Arctic and Antarctic Circle regions. Their name derives from the Latin ''tursio'' (dolphin) and ''truncatus'' for the truncated teeth (the type specimen was old and had worn down teeth; this is not a typical characteristic of most members of the species). Numerous investigations of bottlenose dolphin intelligence have bee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fraser's Dolphin
Fraser's dolphin or the Sarawak dolphin (''Lagenodelphis hosei'') is a cetacean in the family Delphinidae found in deep waters in the Pacific Ocean and to a lesser extent in the Indian and Atlantic Oceans. Taxonomy ''Lagenodelphis hosei'' is species of the delphinid family, distinguished from other dolphins as a monotypic genus, ''Lagenodelphis''. In 1895, Charles E. Hose found a skull on a beach in Sarawak, Borneo. He donated it to the British Museum. The skull remained unstudied until 1956 when Francis Fraser examined it and concluded that it was similar to species in both the genera '' Lagenorhynchus'' and '' Delphinus'' but not the same as either. A new genus was created by simply merging these two names together. The specific name is given in Hose's honour. It wasn't until 1971 that the whole body of a Fraser's dolphin, as it was by then becoming known, was discovered. At that time washed-up specimens were found on Cocos Island in the eastern Pacific, in South Australi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinner Dolphin
The spinner dolphin (''Stenella longirostris'') is a small dolphin found in off-shore tropical waters around the world. It is famous for its acrobatic displays in which it rotates around its longitudinal axis as it leaps through the air. It is a member of the family Delphinidae of toothed whales. Taxonomy The spinner dolphin is sometimes referred to as the long-snouted dolphin, particularly in older texts, to distinguish it from the similar Clymene dolphin, which is often called the short-snouted spinner dolphin. The species was described by John Gray in 1828. The four named subspecies are: *Eastern spinner dolphin (''S. l. orientalis''), from the tropical eastern Pacific. *Central American or Costa Rican spinner dolphin (''S. l. centroamericana''), also found in the tropical eastern Pacific. *Gray's or Hawaiian spinner dolphin (''S. l. longirostris''), from the central Pacific Ocean around Hawaii but represents a mixture of broadly similar subtypes found worldwide. *Dwarf s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Echolocation
Echolocation, also called bio sonar, is a biological active sonar used by several animal groups, both in the air and underwater. Echolocating animals emit calls and listen to the Echo (phenomenon) , echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects. Echolocation is used for animal navigation , navigation, foraging, and predation, hunting prey. Echolocation calls can be Frequency modulation, frequency modulated (FM, varying in pitch during the call) or constant frequency (CF). FM offers precise range discrimination to localize the prey, at the cost of reduced operational range. CF allows both the prey's velocity and its movements to be detected by means of the Doppler effect. FM may be best for close, cluttered environments, while CF may be better in open environments or for hunting while perched. Echolocating animals include mammals, especially odontocetes (toothed whales) and some bat species, and, using s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matrilineality
Matrilineality, at times called matriliny, is the tracing of kinship through the female line. It may also correlate with a social system in which people identify with their matriline, their mother's lineage, and which can involve the inheritance of property and titles. A matriline is a line of descent from a female ancestor to a descendant of either gender in which the individuals in all intervening generations are mothers. In a matrilineal descent system, individuals belong to the same descent group as their mothers. This is in contrast to the currently more popular pattern of patrilineal descent from which a family name is usually derived. The matriline of historical nobility was also called their enatic or uterine ancestry, corresponding to the patrilineal or "agnatic" ancestry. Early human kinship Scholars disagree on the nature of early human, that is, Homo sapiens, kinship. In the late 19th century, most scholars believed, influenced by Lewis H. Morgan's book ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diel Vertical Migration
Diel vertical migration (DVM), also known as diurnal vertical migration, is a pattern of movement used by some organisms, such as copepods, living in the ocean and in lakes. The adjective "diel" ( IPA: , ) comes from , and refers to a 24-hour period. The migration occurs when organisms move up to the uppermost layer of the water at night and return to the bottom of the daylight zone of the oceans or to the dense, bottom layer of lakes during the day. DVM is important to the functioning of deep-sea food webs and the biologically-driven sequestration of carbon. In terms of biomass, DVM is the largest synchronous migration in the world. It is not restricted to any one taxon, as examples are known from crustaceans (copepods), molluscs (squid), and ray-finned fishes (trout). The phenomenon may be advantageous for a number of reasons, most typically to access food and to avoid predators. It is triggered by various stimuli, the most prominent being changes in light-inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesopelagic
The mesopelagic zone (Greek language, Greek μέσον, middle), also known as the middle pelagic or twilight zone, is the part of the pelagic zone that lies between the photic epipelagic and the aphotic bathypelagic zones. It is defined by light, and begins at the depth where only 1% of incident light reaches and ends where there is no light; the depths of this zone are between approximately below the Sea level, ocean surface. The mesopelagic zone occupies about 60% of the planet's surface and about 20% of the ocean's volume, amounting to a large part of the total biosphere. It hosts a diverse biological community that includes Gonostomatidae, bristlemouths, Psychrolutidae, blobfish, bioluminescent jellyfish, giant squid, and myriad other unique organisms adapted to live in a low-light environment. It has long captivated the imagination of scientists, artists and writers; deep sea creatures are prominent in popular culture. Physical conditions The mesopelagic zone includes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
