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Typhlonarke
''Typhlonarke'' is a genus of sleeper ray in the family Narkidae, containing two poorly known species. The group is known for producing electric shocks for defense. Both species are deep-sea rays endemic to the waters off New Zealand. They are not to be confused with the blind electric rays of the genus ''Benthobatis''. Taxonomy ''Typhlonarke'' was created by Edgar R. Waite, in a 1909 issue of the scientific journal ''Records of the Canterbury Museum''. Species * '' Typhlonarke aysoni'' A. Hamilton, 1902 (Blind electric ray) * '' Typhlonarke tarakea'' Phillipps, 1929 (Oval electric ray) Distribution and habitat Both ''Typhlonarke'' species are native to New Zealand; the exact distribution of each species is uncertain due to confusion between the two. They have been caught by trawls off the east coast of North Island south of East Cape, South Island, Stewart Island/Rakiura, Chatham Rise ( Mernoo Bank and Chatham Islands), and the Snares Shelf. They occur at a depth of 46–800 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Typhlonarke Tarakea
The oval electric ray (''Typhlonarke aysoni'') is a little-known species of sleeper ray in the family Narkidae. It is endemic to New Zealand, where it is generally found on the sea floor at a depth of . Seldom exceeding in length, this species has a thick, oval pectoral fin disc and a short, stout tail with a single dorsal fin. It is blind, as its tiny eyes are covered by skin. Its pelvic fins are divided in two, with the anterior portion forming a limb-like appendage. These appendages likely allow the ray, which may not be able to swim at all, to "walk" along the bottom. The claspers of adult males extend beyond the disc. Polychaete worms are known to be part of its diet, and its reproduction is aplacental viviparous. It can produce an electric shock for defense. The International Union for Conservation of Nature presently lacks the data to assess its conservation status. Taxonomy The oval electric ray was described by William John Phillipps of the Dominion Museum, in a 1929 vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blind Electric Ray
The blind electric ray (''Typhlonarke aysoni'') is a little-known species of sleeper ray in the family Narkidae, endemic to New Zealand. It is found on the bottom, typically at a depth of . Reaching in length, this species has a thin, nearly circular pectoral fin disc without visible eyes, and a short tail with a single dorsal fin. Its pelvic fins are divided in two, with the anterior portion forming a limb-like appendage; in males the claspers do not extend past the disc margin. A weak swimmer, the blind electric ray likely pushes itself along using its pelvic fins. It is known to feed on polychaete worms, and can defend itself with an electric shock. Reproduction is aplacental viviparous. The International Union for Conservation of Nature (IUCN) does not have enough information to assess the conservation status of this species. Taxonomy The trawler ''Doto'' collected the first known specimen of the blind electric ray from the Foveaux Strait, during a research cruise in early 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sleeper Ray
Members of the family Narkidae are commonly known as sleeper rays. They are restricted to the temperate and tropical Indo-West Pacific from South Africa to Japan to Indonesia, and are exclusively marine and are absent from freshwater habitats. They occur from the intertidal zone to the continental shelf and the upper continental slope to a depth of 350 meters, favoring soft-bottomed habitats. Description Adult sleeper rays range in size from 8 to 46 cm in length and have flattened oval, circular, or pear-shaped pectoral fin discs. They have naked skin, without dermal denticles or thorns. The snout is moderately elongate and broadly rounded, with the rostral cartilage reduced to a slender medial rod. This distinguishes the narkids from the family Narcinidae, which have somewhat longer snouts supported by broad rostral cartilages. The mouth is straight, very narrow, and not highly protrusible, with strong labial folds and a weak groove around the periphery. The nostrils are pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narkidae
Members of the family Narkidae are commonly known as sleeper rays. They are restricted to the temperate and tropical Indo-West Pacific from South Africa to Japan to Indonesia, and are exclusively marine and are absent from freshwater habitats. They occur from the intertidal zone to the continental shelf and the upper continental slope to a depth of 350 meters, favoring soft-bottomed habitats. Description Adult sleeper rays range in size from 8 to 46 cm in length and have flattened oval, circular, or pear-shaped pectoral fin discs. They have naked skin, without dermal denticles or thorns. The snout is moderately elongate and broadly rounded, with the rostral cartilage reduced to a slender medial rod. This distinguishes the narkids from the family Narcinidae, which have somewhat longer snouts supported by broad rostral cartilages. The mouth is straight, very narrow, and not highly protrusible, with strong labial folds and a weak groove around the periphery. The nostrils are p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chatham Rise
The Chatham Rise is an area of ocean floor to the east of New Zealand, forming part of the Zealandia continent. It stretches for some from near the South Island in the west, to the Chatham Islands in the east. It is New Zealand's most productive and important fishing ground, as well as important habitat for whales. Relative to the rest of the Pacific Ocean waters around New Zealand, the Chatham Rise is relatively shallow, no more than deep at any point. This shallowness is made more remarkable by the depth of the ocean immediately to the north and south. To the northeast, the Hikurangi Trench, an extension of the much deeper Kermadec Trench, drops to below close to the New Zealand coast, and further from the coast the Rise borders on the Hikurangi Plateau. To the south, similar depths are achieved in the Bounty Trough. Past the eastern end of the rise, the sea floor drops away to the abyssal plain. Geology Geologically and tectonically, the Chatham Rise can be thought of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chatham Islands
The Chatham Islands ( ) ( Moriori: ''Rēkohu'', 'Misty Sun'; mi, Wharekauri) are an archipelago in the Pacific Ocean about east of New Zealand's South Island. They are administered as part of New Zealand. The archipelago consists of about ten islands within an approximate radius, the largest of which are Chatham Island and Pitt Island (Rangiauria). They include New Zealand's easternmost point, the Forty-Fours. Some of the islands, formerly cleared for farming, are now preserved as nature reserves to conserve some of the unique flora and fauna. The islands were uninhabited when the Moriori people arrived around 1500 CE and developed a peaceful way of life. In 1835 members of the Ngāti Mutunga and Ngāti Tama Māori iwi from the North Island of New Zealand invaded the islands and nearly exterminated the Moriori, enslaving the survivors. Later during the period of European colonisation of New Zealand, the New Zealand Company claimed that the British Crown had never ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectoral Fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cartilaginous Fish
Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue. Chondrichthyes are jawed vertebrates with paired fins, paired nares, scales, and a heart with its chambers in series. Extant chondrichthyes range in size from the 10 cm (3.9 in) finless sleeper ray to the 10 m (32 ft) whale shark. The class is divided into two subclasses: Elasmobranchii ( sharks, rays, skates, and sawfish) and Holocephali (chimaeras, sometimes called ghost sharks, which are sometimes separated into their own class). Within the infraphylum Gnathostomata, cartilaginous fishes are distinct from all other jawed vertebrates. Anatomy Skeleton The skeleton is cartilaginous. The notochord is gradually replaced by a vertebral column during development, except in Holocephali, where the notochord stays intact. In so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Island
The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, and to the south and east by the Pacific Ocean. The South Island covers , making it the world's 12th-largest island. At low altitude, it has an oceanic climate. The South Island is shaped by the Southern Alps which run along it from north to south. They include New Zealand's highest peak, Aoraki / Mount Cook at . The high Kaikōura Ranges lie to the northeast. The east side of the island is home to the Canterbury Plains while the West Coast is famous for its rough coastlines such as Fiordland, a very high proportion of native bush and national parks, and the Fox and Franz Josef Glaciers. The main centres are Christchurch and Dunedin. The economy relies on agriculture and fishing, tourism, and general manufacturing and serv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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