Skip to main content Skip to main navigation menu Skip to site footer
Type: Article
Published: 2016-08-16
Page range: 537–565
Abstract views: 201
PDF downloaded: 6

Potamotrygon rex, a new species of Neotropical freshwater stingray (Chondrichthyes: Potamotrygonidae) from the middle and upper rio Tocantins, Brazil, closely allied to Potamotrygon henlei (Castelnau, 1855)

Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Trav. 14, no. 101, 05508-090, São Paulo, SP, Brazil.
Pisces Potamotrygon P. leopoldi black stingrays endemism morphology systematics taxonomy Brazilian Shield

Abstract

A systematic revision of the rio Tocantins stingrays has confirmed the occurrence of a new species of Potamotrygon first discovered more than two decades ago but which lacked material for a thorough description. Field surveys since undertaken in the middle and upper rio Tocantins have assembled significant material that forms the basis of an ongoing revision of the diverse Tocantins potamotrygonid assemblage. Potamotrygon rex, sp. nov., is a very large, "black stingray" species from the mid and upper rio Tocantins that is closely related to P. henlei (Castelnau), which occurs in the lower Tocantins basin and in rio Araguaia; both species do not co-occur. Potamotrygon rex, sp. nov., has a unique blackish to dark brown dorsal color with numerous small, yellow to orange irregular spots usually forming distinct clusters on dorsal disc, with ocelli in center of clusters on posterior and outer disc, dorsal tail also with clusters but lateral tail with ocelli, and a dark brownish to gray color covering most of ventral surface except nasoral region, gill slits and anterior snout in some specimens, with small whitish spots on ventral disc, pelvic fins and tail. Potamotrygon rex, sp. nov., can be further distinguished by its broad pelvic-fin apices, lack of labial grooves, irregular double row of dorsal tail thorns, and in having two angular cartilages associated with each hyomandibula. Potamotrygon rex, sp. nov., P. henlei, P. leopoldi Castex & Castello, and another new Potamotrygon species from the rio Tapajós (in description) form a species-group (the "black stingrays") occurring in rivers draining the central Brazilian shield, characterized by their black to dark brown but highly ornate dorsal color, wide pelvic fins with broadly convex apices, among other features. Potamotrygon rex, sp. nov., is the 25th species of Potamotrygon, and highlights that very large new species of fishes still await discovery and description in the Neotropical region.

 

References

  1. Agostinho, C.S., Pelicice, F.M. & Marques, E.E. (Eds.) (2008) Reservatório de Peixe Angical: Bases Ecológicas para o Manejo da Ictiofauna. São Carlos, Rima Editora. 179 pp.

    Albert, J.S., Petry, P. & Reis, R.E. (2011) Major biogeographic and phylogenetic patterns. In: Albert, J.S. & Reis, R.E. (Eds.), Historical Biogeography of Neotropical Freshwater Fishes. Berkeley, Univ. Calif. Press, pp. 21–57.

    Carvalho, M.R. de & Lovejoy, N.R. (2011) Morphology and phylogenetic relationships of a remarkable new genus and two new species of Neotropical freshwater stingrays from the Amazon basin (Chondrichthyes: Potamotrygonidae). Zootaxa 2776, 13–48.

    Carvalho, M.R. de, Lovejoy, N.R. & Rosa, R.S. (2003) Potamotrygonidae. In: Reis, R.E., Ferraris Jr., C.J. & Kullander, S.O. (Eds.), Checklist of freshwater fishes of South and Central America. Porto Alegre, Editora da Pontifícia Universidade Católica, pp. 22–29.

    Carvalho, M.R. de, Maisey, J.G. & Grande, L. (2004) Freshwater stingrays of the Green River Formation of Wyoming (Early Eocene), with the description of a new genus and species and an analysis of its phylogenetic relationships (Chondrichthyes: Myliobatiformes). Bulletin of the American Museum of Natural History, 284, 1–136.
    http://dx.doi.org/10.1206/0003-0090(2004)284<0001:FSOTGR>2.0.CO;2

    Carvalho, M.R. de, Rosa, R.S. & Araújo, M.L.G. de. (2016) A new species of Neotropical freshwater stingray (Chondrichthyes: Potamotrygonidae) from the Rio Negro, Amazonas, Brazil: the smallest species of Potamotrygon. Zootaxa, 4107 (4), 566–586.
    http://dx.doi.org/10.11646/zootaxa.4107.4.5

    Carvalho, M.R. de, Sabaj-Perez, M. & Lovejoy, N.R. (2011) Potamotrygon tigrina, a new species of freshwater stingray from the upper Amazon basin, closely related to Potamotrygon schroederi Fernandez-Yépez, 1958 (Chondrichthyes: Potamotrygonidae). Zootaxa, 2827, 1−30.

    Castelnau, F.L. (1855) Poissons. In: Animaux nouveaux or rares recueillis pendant l'expédition dans les parties centrales de l'Amérique du Sud, de Rio de Janeiro a Lima, et de Lima au Para; exécutée par ordre du gouvernement Français pendant les années 1843 a 1847. Part 7, Zoologie (2), 1−112, 50 pls. Paris, P. Bertrand.

    Duméril, A.H.A. (1865) Histoire naturelle des poissons ou ichthyologie générale. Tome Premier. I. Elasmobranches. Plagiostomes et Holocéphales ou Chimères. Vol. 1, 1−720; Atlas, pp. 1−8, Pls. 1−14.

    Ferreira, E., Zuanon, J., Santos, G. & Amadio, S. (2011) The fish fauna of the Parque Estadual do Cantão, Araguaia River, State of Tocantins, Brazil. Biota Neotropica, 11 (2). Avaliable from: http://www.biotaneotropica.org.br/v11n2/en/inventory?article+bn01711022011 (Accessed 15 Aug. 2016)

    Fontenelle, J.P., Silva, J.P.C.B. da & Carvalho, M.R. de (2014) Potamotrygon limai, sp. nov., a new species of freshwater stingray from the upper Madeira River system, Amazon basin (Chondrichthyes: Potamotrygonidae). Zootaxa, 3765 (3), 249–268.
    http://dx.doi.org/10.11646/zootaxa.3765.3.2

    Gama, C.S. & Rosa, R.S. (2014) Potamotrygon dumerilli. pp. 176−180. In: Lasso, C.A., Rosa, R.S., Sánchez-Duarte, P., Morales-Betancourt, M.A. & Agudelo-Córdoba, E. (Eds.), Rayas de Agua Dulce (Potamotrygonidae) de Suramérica Parte I. Instituto de Investigacíon de Recursos Biológicos Alexander von Humboldt, Colombia, 368 pp.

    Garman, S. (1877) On the pelvis and external sexual organs of selachiens, with special reference to the new genera Potamotry-gon and Disceus. Proceedings of the Boston Society of Natural History, 19, 197–215.

    Garman, S. (1913) The Plagiostomia (sharks, skates and rays). Memoirs of the Museum of Comparative Zoology, 36, i-xiii + 1–515, 75 pls.

    Géry, J. (1969) The fresh-water fishes of South America. In: Fittkau, E.J., Illies, J., Klinge, H., Schwabe, G.H. & Sioli, H. (Eds.), Biogeography and Ecology in South America. Dordrecht, Dr. W. Junk Publ, pp. 828–848.

    Günther, A. (1870) Catalogue of the Fishes in the British Museum. Vol. 8. London, British Museum (Natural History). 549 pp.

    Lima, F.C.T. & Ribeiro, A.C. (2011) Continental-scale tectonic controls of biogeography and ecology. In: Albert, J.S. & Reis, R.E. (Eds.), Historical Biogeography of Neotropical Freshwater Fishes. Berkeley, Univ. Calif. Press, pp. 145–164.

    Loboda, T.S. & Carvalho, M.R. de (2013) Systematic revision of the Potamotrygon motoro (Müller & Henle, 1841) species complex in the Paraná-Paraguay basin, with description of two new ocellated species (Chondrichthyes: Myliobatiformes: Potamotrygonidae). Neotropical Ichthyology, 11 (4), 693–737.
    http://dx.doi.org/10.1590/S1679-62252013000400001

    Lucinda, P.H.F., Freitas, I.S., Soares, A.B., Marques, E.E., Agostinho, C.S. & Oliveira, R.J. (2007) Fish, Lajeado Reservoir, rio Tocantins drainage, State of Tocantins, Brazil. Check List, 2007, 70–83.

    Nishida, K. (1990) Phylogeny of the suborder Myliobatidoidei. Memoirs of the Faculty of Fisheries Hokkaido University, 37 (1/2), 1–108.

    Ribeiro, M.C.L. de B., Petrere, M. & Juras, A.A. (1995) Ecological integrity and fisheries ecology of the Araguaia-Tocantins basin, Brazil. Regulated Rivers: Research and Management, 11 (3), 325–350.
    http://dx.doi.org/10.1002/rrr.3450110308

    Rincon, G., Rosa, R.S. & Carvalho, M.R. de (2014) Potamotrygon henlei. In: Lasso, C.A., Rosa, R.S., Sánchez-Duarte, P., Morales-Betancourt, M.A. & Agudelo-Córdoba, E. (Eds.), Rayas de Agua Dulce (Potamotrygonidae) de Suramérica Parte I. Instituto de Investigacíon de Recursos Biológicos Alexander von Humboldt, Colombia, pp. 184–189.

    Rosa, R.S. (1985) A systematic revision of the South American freshwater stingrays (Chondrichthyes: Potamotrygonidae). Unpublished PhD diss. The College of William and Mary, Williamsburg, 523 pp.

    Rosa, R.S., Carvalho, M.R. de & Wanderley, C.A. (2008) Potamotrygon boesemani (Chondrichthyes: Myliobatiformes: Potamotrygonidae), a new species of Neotropical freshwater stingray from Surinam. Neotropical Ichthyology, 6 (1), 1–8.

    Rosa, R.S., Charvet-Almeida, P. & Quijada, C.C.D. (2010) Biology of the South American potamotrygonid stingrays. In: Carrier, J.C., Musick, J.A. & Heithaus, M.R. (Eds.), Sharks and Their Relatives II: Biodiversity, Adaptive Physiology, and Conservation. CRC Press, Boca Raton, pp. 241–285.

    Sabaj Pérez, M.H. (Ed.) (2014) Standard symbolic codes for institutional resource collections in herpetology and ichthyology: an Online Reference. Version 5.0 (22 September 2014). Available from: http://www.asih.org/ American Society of Ichthyologists and Herpetologists, Washington, DC.

    Santos, A.A. dos (2000) Morfologia externa, alimentação e reprodução de raias do alto e médio rio Tocantins (Chondrichthyes, Potamotrygonidae). Unpubl. Bachelor's monograph, Univ. Federal do Tocantins, 23 pp.

    Santos, G.M., Mérona, B., Jonas, A.A. & Jégu, M. (2004) Peixes do Baixo Rio Tocantins: 20 anos Depois da Usina Hidrelétrica Tucuruí. Brasília, Eletronorte, 215 pp.

    Silva, J.P.C.B. da & Carvalho, M.R. de (2011) A taxonomic and morphological redescription of Potamotrygon falkneri Castex & Maciel, 1963 (Chondrichthyes: Myliobatiformes: Potamotrygonidae). Neotropical Ichthyology, 9 (1), 209–232.
    http://dx.doi.org/10.1590/S1679-62252011000100021

    Silva, J.P.C.B. da & Carvalho, M.R. de (2015) Systematics and morphology of Potamotrygon orbignyi (Castelnau, 1855) and allied forms (Chondrichthyes: Myliobatiformes: Potamotrygonidae). Zootaxa, 3982 (1), 1–82.
    http://dx.doi.org/10.11646/zootaxa.3982.1.1

    Soares, A.B., Pelicice, F.M., Lucinda, P.H.F. & Akama, A. (2008) Diversidade de peixes na área de influência da barragem de Peixe Angical, antes e após a formação do reservatório. In: Agostinho, C.S., Pelicice, F.M. & Marques, E.E. (Eds.), Reservatório de Peixe Angical: Bases Ecológicas para o Manejo da Ictiofauna. São Carlos, Rima Editora, pp. 15–27.

    Venere, P.C. & Garutti, V. (2011) Peixes do Cerrado, Parque Estadual da Serra Azul, Rio Araguaia, MT. São Carlos, Rima Editora, 207 pp.