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| Knodus ytuanama |
Abstract
Knodus ytuanama, new species, is described from the upper rio Juruena, rio Tapajós drainage, Amazon basin, Mato Grosso, Brazil. The new species differs from its congeners by presenting the interradial membranes of the caudal fin thickened, forming folds, and also differs from most congeners by the presence of a dark, wide midlateral stripe extending from the posterior margin of opercle to the middle caudal-fin rays, the absence of a humeral blotch in adults, and by having four rows of scales between the lateral line and the pelvic-fin origin, among another features. We also provide a discussion on the presence of membranous flaps on the fins as an adaptation for living in fast-water environments in Knodus ytuanama n. sp. as well as in a congener, K. tiquiensis.
Key words: Knodus tiquiensis, Diapomini, Amazon Basin, rheophily
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| Knodus ytuanama, holotype, CPUFMT 7756, 81.2 mm SL: Brazil, Mato Grosso, Comodoro, rio Mutum. |
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| Knodus ytuanama INPA 59847, paratypes, 83.2 mm SL (upper) and 75.7 mm SL (lower), immediately after capture. |
Knodus ytuanama, new species
Etymology. The specific epithet ytuanama derives from the Tupi language, from the words ytu, waterfall, andanama, friend, and it refers to the fast-flowing habitat of the new species. A noun in apposition.
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| Type locality of Knodus ytuanama, rio Mutum near road BR-174, affluent of upper rio Juruena, rio Tapajós basin, Comodoro, Mato Grosso, Brazil. |
Katiane M. Ferreira and Willian Massaharu Ohara. 2022. A New Rheophilic Species of Knodus Eigenmann (Characiformes: Characidae: Stevardiinae) from the upper rio Juruena, rio Tapajós basin, Chapada dos Parecis, Mato Grosso, Brazil. Zootaxa. 5227(3); 365-377
