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Orden Resumen for Gymnotiformes
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Referencia principal |
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Orden |
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Gymnotiformes knifefishes |
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Clase |
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Teleostei |
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Orden hermana |
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Siluriformes 150 M years |
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Referencia |
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Primer expediente de fósil |
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late Miocene |
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Ocurre en |
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Marino |
Dulce |
Salobre |
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Observación |
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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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Clase Etimologia |
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Greek aktis = ray, thunderbolt, beam + Greek pterygion, diminutive of pteryx = wing, fin. Ref. 45335. |
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Orden Etimologia |
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Greek, gymnos = naked + Latin, forma = shape (Ref. 45335); ous or otos refers to opercle. |
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Familias |
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