Abstract
Otothyropsis dialeukos is described from Itá creek, tributary to the upper Río Paraná basin, Paraguay. The new species is distinguished from its congeners by having a unique caudal-fin coloration pattern composed of a brown to almost black background with roundish hyaline blotches in the middle of the outermost branched rays and a hyaline posterior border interrupted in middle rays; abdomen entirely covered by enlarged plates, without naked areas; longer pectoral- and dorsal-fin spines; absence of a raised crest of enlarged odontodes on the posterior portion of the parieto-supraoccipital, and other morphometric and meristic features. Morphological traits and geographic distributions of all species of Otothyropsis and Hisonotus are analyzed and a discussion on the limits between those genera is presented.
References
Calegari, B.B., Lehmann A.P. & Reis, R.E. (2011) A new species of Otothyropsis (Siluriformes: Loricariidae) from the río Paraguay basin, Paraguay. Neotropical Ichthyology, 9 (2), 253–260.
http://dx.doi.org/10.1590/S1679-62252011000200002
Calegari, B.B., Lehmann, A.P. & Reis, R.E. (2013) Two new species of cascudinhos of the genus Otothyropsis (Siluriformes: Hypoptopomatinae) from the rio Paraná basin, Brazil. Zootaxa, 3619 (2), 130–144.
https://doi.org/10.11646/zootaxa.3619.2.2Calegari, B.B., Silva, E.V. & Reis, R.E. (2014) Microlepidogaster discontenta, a new species of hypoptopomatine catfish (Teleostei: Loricariidae) from the rio São Francisco basin, Brazil. Ichthyological Exploration of Freshwaters, 25 (3), 213–221.
Chiachio, M.C., Oliveira, C. & Montoya-Burgos, J.I. (2008) Molecular systematic and historical biogeography of the armored Neotropical catfishes Hypoptopomatinae and Neoplecostominae (Siluriformes: Loricariidae). Molecular Phylogenetics and Evolution, 49, 606–617.
https://doi.org/10.1016/j.ympev.2008.08.013Cramer, C.A., Bonatto, S.L. & Reis, R.E. (2011) Molecular phylogeny of the Neoplecostominae and Hypoptopomatinae (Siluriformes: Loricariidae) using multiple genes. Molecular Phylogenetics and Evolution, 59, 43–52.
https://doi.org/10.1016/j.ympev.2011.01.002Lippert, B.G., Calegari, B.B. & Reis, R.E. (2014) A New Species of Otothyropsis (Siluriformes: Hypoptopomatinae) from Eastern Brazil. Copeia, 2014 (2), 238–244.
https://doi.org/10.1643/CI-13-057Martins, F.O., Britski, H.A. & Langeani, F. (2014) Systematics of Pseudotothyris (Loricariidae: Hypoptopomatinae). Zoological Journal of the Linnean Society, 170, 822–874.
https://doi.org/10.1111/zoj.12107Pereira, E.H.L., Vieira, F. & Reis, R.E. (2007) A new species of sexually dimorphic Pareiorhaphis Miranda Ribeiro, 1918 (Siluriformes: Loricariidae) from the rio Doce basin, Brazil. Neotropical Ichthyology, 5 (4), 443–448.
https://doi.org/10.1590/S1679-62252007000400003Ribeiro, A.C., Carvalho, M. & Melo, A.L.A. (2005) Description and relationships of Otothyropsis marapoama, a new genus and species of Hypoptopomatinae catfish (Siluriformes: Loricariidae) from rio Tietê basin, southeastern Brazil. Neotropical Ichthyology, 3 (4), 489–498.
https://doi.org/10.1590/S1679-62252005000400006Ribeiro, A.C., Jacob, R.M., Silva, R.R.S.R., Lima, F.C.T., Ferreira, D.C., Ferreira, K.M., Mariguela, T.C., Pereira, L.H.G. & Oliveira, C. (2013) Distributions and phylogeographic data of rheophilic freshwater fishes provide evidences on the geographic extension of a central-Brazilian amazonian palaeoplateau in the area of the present day Pantanal Wetland. Neotropical Ichthyology, 11 (2), 319–326.
https://doi.org/10.1590/S1679-62252013000200010Roxo, F.F., Albert, J.S. Silva, G.S., Zawadzki, C.H., Foresti, F. & Oliveira, C. (2014) Molecular Phylogeny and Biogeographic History of the Armored Neotropical Catfish Subfamilies Hypoptopomatinae, Neoplecostominae and Otothyrinae (Siluriformes: Loricariidae). PLoS ONE, 9 (8), 1–17.
https://doi.org/10.1371/journal.pone.0105564Roxo, F.F., Silva, G.S., Ochoa, L.E. & Oliveira, C. (2015) Description of a new genus and three new species of Otothyrinae (Siluriformes, Loricariidae). Zookeys, 534, 103–134.
https://doi.org/10.3897/zookeys.534.6169Roxo, F.F., Silva, G.S., Waltz, B.T. & Melo, J.E.G. (2016) A new species of Hisonotus (Siluriformes: Otothyrinae) from the upper rio Paraná and rio São Francisco basins, Brazil. Zootaxa, 4109 (2), 227–238.
https://doi.org/10.11646/zootaxa.4109.2.7Schaefer, S.A. (1997) The neotropical cascudinhos: Systematics and biogeography of the Otocinclus catfishes (Siluriformes: Loricariidae). Proceedings of the Academy of Natural Sciences of Philadelphia, 148, 1–120.
Schaefer, S.A. (2003) Hypoptopomatinae. In: Reis, R.E., Kullander, S.O. & Ferraris Jr., C.J. (Eds.), Checklist of the Freshwater Fishes of South and Central America. Edipucrs, Porto Alegre, pp. 321–329.
Taylor, W.R. & van Dyke, G.C. (1985) Revised procedures for staining and clearing small fishes and other vertebrates for bone and cartilage study. Cybium, 9 (2), 107–119.