क्रम सारांश for Gymnotiformes
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मुख्य संदर्भ |
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क्रम |
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Gymnotiformes knifefishes |
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वर्ग |
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Teleostei |
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Sister Order |
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Siluriformes 150 M years |
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संदर्भ |
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First Fossil Record |
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late Miocene |
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Occurs in |
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समुद्री |
Fresh |
खारा |
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टिप्पणी |
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Body eel-like (compressed or rounded); pelvic girdle and fins absent; dorsal fin absent; anal fin extremely long (more than 140 rays and extending from near pectoral fin origin to near tip of body) and employed in forward and backward movements; caudal fin absent or greatly reduced; restricted gill openings; anal opening under head or pectorals; basal pterygiophores to anal fin with only one section (radial) and a hemispherical cartilaginous head that articulates the fin rays (allowing them to move in a circular motion); electric organs present; suboperculum absent; palatine not ossified; maxilla rudimentary. |
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वर्ग etymology |
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Greek aktis = ray, thunderbolt, beam + Greek pterygion, diminutive of pteryx = wing, fin. Ref. 45335. |
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क्रम etymology |
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Greek, gymnos = naked + Latin, forma = shape (Ref. 45335); ous or otos refers to opercle. |
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परिवार |
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