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Oval electric ray
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 volume of the ''New Zealand Journal of Science and Technology''. The type specimen was collected off Island Bay, Wellington. A specimen of this ray had been illustrated earlier by Augustus Hamilton, in his 1909 description of the related ''T. aysoni''. Hamilton obtained the specimen at the fish market at Dunedin and made note of its different shape, but did not recognize it as a distinct species. Along with ''T. aysoni'', this species may also be called the blind electric ray.〔
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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