Abstract
The genus Trichomycterus is a highly diverse group of Neotropical catfishes that encompass almost 60% of all the cur-rently recognized species of the Trichomycteridae. A new species of this genus, T. perkos, is herein described from tribu-taries of the Paranapanema and Uruguai River basins, southern Brazil. The new species exhibits a remarkable ontogeneticchange in its pigmentation, having a unique color pattern when adult. The adult pigmentation consists of three wide darkbrown stripes, located in an inner skin layer of trunk and caudal peduncle, combined with a superficial light brown freck-led pattern on the dorsum and caudal peduncle. Small, presumably juvenile specimens lack the superficial freckles butalready have the dark stripes, thus resembling the color pattern of a few other congeners. Nevertheless, several unequiv-ocal morphological features distinguish both juveniles and adults of T. perkos from these congeners. In spite of the diffi-culties in estimating phylogenetic relationships within Trichomycterus, the new species is tentatively proposed as being the sister-taxon of a small group of species composed by T. crassicaudatus, T. igobi, and T. stawiarski.References
Alencar, A.R. & Costa, W.J.E.M. (2006) Trichomycterus pauciradiatus, a new catfish species from the upper rio Paraná basin, southeastern Brazil (Siluriformes: Trichomycteridae). Zootaxa, 1269, 43–49.
Arratia, G. (1990) The South American Trichomycterinae (Teleostei: Siluriformes), a problematic group. In: Petersand, G. & Hutterer, R. (Eds.), International Symposium on Vertebrate Biogeography and Systematics in the Tropics. Alexander Koenig Zoological Research Institute and Zoological Museum, Bonn, pp. 395–403.
Arratia, G. (1998) Silvinichthys, a new genus of trichomycterid catfishes from the Argentinian Andes, with redescription of Trichomycterus nigricans. Ichthyological Exploration of Freshwaters, 9, 347–370.
Arratia, G. (2008) Actinopterygian postcranial skeleton with special reference to the diversity of fin ray elements, and the problem of identifying homologies. In: Arratia, G., Schultze, H.-P. & Wilson, M.V.H. (Eds.), Mesozoic Fishes 4 - Homology and Phylogeny. Verlag Dr. Friedrich Pfeil, München, pp. 49–101.
Arratia, G. & Menu-Marque, S. (1984) New catfishes of the genus Trichomycterus from the high Andes of South America (Pisces, Siluriformes) with remarks on distribution and ecology. Zoologische Jahrbücher. Abteilung für Systematik, Geographie und Biologie der Tiere, 111, 493–520.
Barbosa, M.A. & Costa, W.J.E.M. (2003) Trichomycterus potschi (Siluriformes: Loricarioidei) a new trichomycterid catfish from coastal streams of southeastern Brazil. Ichthyologial Exploration of Freshwaters, 14, 281–287.
Barbosa, M.A. & Costa, W.J.E.M. (2008) Description of a new species of catfish from the upper rio Paraíba do Sul basin, south-eastern Brazil (Teleostei: Siluriformes: Trichomycteridae) and re-description of Trichomycterus itatiayae. aqua, International Journal of Ichthyology, 14, 175–186.
Baskin, J.N. (1973) Structure and relationship of the Trichomycteridae. City University of New York, New York, 389 pp.
Bockmann, F.A., Casatti, L. & de Pinna, M.C.C. (2004) A new species of trichomycterid catfish from the Rio Paranapanema basin, southeastern Brazil (Teleostei: Siluriformes), with comments on the phylogeny of the family. Ichthyological Exploration of Freshwaters, 15, 225–242.
Bockmann, F.A. & Sazima, I. (2004) Trichomycterus maracaya, a new catfish from the upper rio Paraná, southeastern Brazil (Siluriformes: Trichomycteridae), with notes on the T. brasiliensis species-complex. Neotropical Ichthyology, 2, 61–74.
Campanario, C.M. & de Pinna, M.C.C. (2000) A new species of the primitive trichomycterid subfamily Copionodontinae from northeastern Brazil (Teleostei: Trichomycteridae). Ichthyologial Exploration of Freshwaters, 11, 369–375.
Caramaschi, E.P. & Caramaschi, U. (1991) Taxonomic status of the trichomycterid catfish Trichomycterus itatiayae. Copeia, 1991, 222–224.
Costa, W.J.E.M. (1992) Description de huit nouvelles espèces du genre Trichomycterus (Siluriformes: Trichomycteridae), du Brésil oriental. Revue Française d’Aquariologie, 18, 101–110.
Costa, W.J.E.M. & Bockmann, F.A. (1993) Un nouveau genre Néotropical de la famille des Trichomycteridae (Siluriformes: Loricarioidei). Revue Française d’Aquariologie, 20, 43–46.
Costa, W.J.E.M. & Bockmann, F.A. (1994) A new genus and species of Sarcoglanidinae (Siluriformes: Trichomycteridae) from southeastern Brazil, with a re-examination of subfamilial phylogeny. Journal of Natural History, 28, 715–730.
Datovo, A. & Bockmann, F.A. (2010) Dorsolateral head muscles of the catfish families Nematogenyidae and Trichomycteridae (Siluriformes: Loricarioidei): comparative anatomy and phylogenetic analysis. Neotropical Ichthyology, 8, 193–246.
Datovo, A. & Landim, M.I. (2005) Ituglanis macunaima, a new catfish from the rio Araguaia basin, Brazil (Siluriformes: Trichomycteridae). Neotropical Ichthyology, 3, 455–464.
de Pinna, M.C.C. (1989) A new sarcoglanidine catfish, phylogeny of its subfamily, and an appraisal of the phyletic status of the Trichomycterinae (Teleostei, Trichomycteridae). American Museum Novitates, 2950, 1–39.
de Pinna, M.C.C. (1992a) A new subfamily of Trichomycteridae (Teleostei, Siluriformes), lower loricarioid relationships and a discussion on the impact of additional taxa for phylogenetic analysis. Zoological Journal of the Linnean Society, 106, 175–229.
de Pinna, M.C.C. (1992b) Trichomycterus castroi, a new species of trichomycterid catfish from the Rio Iguaçu of Southeastern Brazil (Teleostei: Siluriformes). Ichthyological Exploration of Freshwaters, 3, 89–95.
de Pinna, M.C.C. (1998) Phylogenetic relationships of Neotropical Siluriformes (Teleostei: Ostariophysi): historical overview and synthesis of hypotheses. In: Malabarba, L.R., Reis, R.E., Vari, R.P., Lucena, Z.M. & Lucena, C.A.S. (Eds.), Phylogeny and Classification of Neotropical Fishes. EDIPUCRS, Porto Alegre, pp. 279–330.
de Pinna, M.C.C. & Ng, H.H. (2004) The second ural centrum in Siluriformes and its implication for the monophyly of superfamily Sisoroidea (Teleostei, Ostariophysi). American Museum Novitates, 3437, 1–23.
de Pinna, M.C.C. & Wosiacki, W.B. (2003) Family Trichomycteridae (Pencil or parasitic catfishes). In: Reis, R.E., Kullander, S.O. & Ferraris, C.J. (Eds.), Check List of the Freshwater Fishes of South and Central America. EDIPUCRS, Porto Alegre, pp. 270–290.
Eigenmann, C.H. (1917) Descriptions of sixteen new species of Pygidiidae. Proceedings of the American Philosophical Society, 56, 690–703.
Eigenmann, C.H. (1918) The Pygidiidae, a family of South American catfishes. Memoirs of the Carnegie Museum, 7, 259–398.
Eschmeyer, W.N. & Fong, J.D. (2011) Species of fishes by family/subfamily, Catalog of Fishes electronic version. Available from http://research.calacademy.org/research/ichthyology/catalog/SpeciesByFamily.asp (accessed 12 December 2011)
Eschmeyer, W.N. & Fricke, R. (2011) Catalog of Fishes electronic version. Available from http://research.calacademy.org/research/ichthyology/catalog/fishcatmain.asp (accessed 12 December 2011).
Ferrer, J. & Malabarba, L.R. (2011) A new Trichomycterus lacking pelvic fins and pelvic girdle with a very restricted range in Southern Brazil (Siluriformes: Trichomycteridae). Zootaxa, 2912, 59–67.
Gottfried, M. D. (1989) Earliest fossil evidence for protective pigmentation in an actinopterygian fish. Historical Biology, 3, 79–83.
Kantek, D.L.Z., Cipriano, R.R., Abilhoa, V., Artoni, R.F. & Cestari, M.M. (2007) Cytotaxonomic and evolutionary considerations about karyotipic data of fishes from the Iguaçu River basin in south of Brazil. Brazilian Archives of Biology and Technology, 50, 793–802.
Lima, S.M.Q. & Costa, W.J.E.M. (2004) Trichomycterus giganteus (Siluriformes: Loricarioidea: Trichomycteridae): a new catfish from the Rio Guandu basin, southeastern Brazil. Zootaxa, 761, 1–6.
Lundberg, J.G. & Baskin, J.N. (1969) The caudal skeleton of the catfishes, order Siluriformes. American Museum Novitates, 2398, 1–49.
Miranda Ribeiro, A. (1906) Vertebrados do Itatiaya (Peixes, Serpentes, Saurios, Aves e Mammiferos). Resultados de excursões do Sr. Carlos Moreira, Assistente de Secção de Zoologia do Museu Nacional. Archivos do Museu Nacional do Rio de Janeiro, 13, 165–190.
Morris, P.J., Yager, H.M. & Sabaj Pérez, M.H. (2006) ACSImagebase: A digital archive of catfish images compiled by participants in the All Catfish Species Inventory. Available from http://acsi.acnatsci.org/base (accessed 12 December 2011).
Sato, L.R., Oliveira, C. & Foresti, F. (2004) Karyotype description of five species of Trichomycterus (Teleostei: Siluriformes: Trichomycteridae). Genetics and Molecular Biology, 27, 45–50.
Schaefer, S.A. & Aquino, A.E. (2000) Postotic laterosensory canal and pterotic branch homology in catfishes. Journal of Morphology, 246, 212–227.
Springer, V.G. & Johnson, G.D. (2004) Study of the dorsal gill-arch musculature of teleostome fishes, with special reference to the Actinopterygii. Bulletin of the Biological Society of Washington, 11, vi+1–260, pl. 1–205.
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, 107–119.
Torres, R.A., Oliveira, C. & Foresti, F. (2004) Cytotaxonomic diagnosis of Trichomycterus diabolus (Teleostei: Trichomycteridae) with comments about its evolutionary relationships with co-generic species. Neotropical Ichthyology, 2, 123–125.
Valpy, F. (1826) The fundamental words of the Greek language, adapted to the memory of the student by means of derivations and derivatives, passages from the classical writers, and other associations. A. J. Valpy, London, xii–362 pp.
Weiszflog, W. (2007) Michaelis Moderno Dicionário da Língua Portuguesa. Editora Melhoramentos Ltda, São Paulo, 2260 pp.
Wosiacki, W.B. & de Pinna, M.C.C. (2008a) A new species of the Neotropical catfish genus Trichomycterus (Siluriformes: Trichomycteridae) representing a new body shape for the family. Copeia, 2008, 273–278.
Wosiacki, W.B. & de Pinna, M.C.C. (2008b) Trichomycterus igobi, a new catfish species from the rio Iguaçu drainage: the largest head in Trichomycteridae (Siluriformes: Trichomycteridae). Neotropical Ichthyology, 6, 17–23.
Wosiacki, W.B. & Oyakawa, O.T. (2005) Two new species of the catfish genus Trichomycterus (Siluriformes: Trichomycteridae) from the rio Ribeira de Iguape Basin, Southeastern Brazil. Neotropical Ichthyology, 3, 465–472.