A New Species of Corumbataia (Siluriformes: Loricariidae: Hypoptopomatinae) from Upper Rio Tocantins Basin, Central Brazil
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Copeia 2008, No. 3, 552–557 A New Species of Corumbataia (Siluriformes: Loricariidae: Hypoptopomatinae) from Upper Rio Tocantins Basin, Central Brazil Tiago Pinto Carvalho1 Corumbataia veadeiros, new species, is described from the upper Rio Tocantins basin at the Chapada dos Veadeiros formation, Goia´s State, central Brazil. The new species is distinguished from all other species of Corumbataia by its lack of a raised tuft of enlarged odontodes on the supraoccipital, an infraorbital canal entering the infraorbital series via the sphenotic, and by the color pattern of the caudal fin, which is composed of vertical dark bars. Corumbataia veadeiros, nova espe´cie, e´ descrita da bacia do alto rio Tocantins na Chapada dos Veadeiros, Goia´s, Brasil central. A nova espe´cie se diferencia das demais do geˆnero Corumbataia pela auseˆncia de um tufo de odonto´ deos alongados no supraoccipital; canal infraorbital entrando na serie infraorbital via esfeno´ tico e pelo padra˜o de colorido da nadadeira caudal, que e´ composto por barras verticais escuras. ORUMBATAIA is part of Hypoptopomatinae, a vertebrae incorporated into the Weberian apparatus), with monophyletic group of loricariids that includes the compound caudal centrum (PU1 + U1) counted as one C more than 100 species grouped in 18 genera element (Lundberg and Baskin, 1969). Cleared-and-stained (Schaefer, 2003; Reis and Carvalho, 2007). Hypoptopoma- specimens (CS) were prepared according to the method of tines are small fishes distributed widely through the cis- Taylor and Van Dyke (1985). Scanning electron microscope Andean drainages of South America from Venezuela to pictures of predorsal region and pectoral-fin spine were northern Argentina (Schaefer, 2003). Corumbataia was taken from dissected alcohol preserved specimens and proposed by Britski (1997) and was first included in a cleared-and-stained specimens, respectively. Accessory phylogenetic scheme by Gauger and Buckup (2005). In that patch of teeth is that described by Reis and Schaefer analysis the genus appears, in the most resolved hypothesis (1992). Institutional abbreviations are as listed at http:// using successive weighting, as sister to Microlepidogaster in a www.asih.org/codons.pdf with the addition of LBP, for clade that also includes Pseudotocinclus, Schizolecis, Pseudo- Laborato´rio de Biologia de Peixes, Departamento de Morfo- tothyris, and Otothyris. logia, Instituto de Biocieˆncias, U.N.E.S.P., Botucatu, Brazil. Until now, three species of Corumbataia have been recognized as valid, all from Brazil: C. cuestae, from creeks Corumbataia veadeiros, new species of the upper Rio Parana´ basin, C. tocantinensis, from creeks of Figure 1, Table 1 the Rio Tocantins basin, and C. britskii, from a tributary of the Rio Sucuriu´ in the upper Rio Parana´ basin (Ferreira and Holotype.—MCN 18571, 32.9 mm SL, male, Brazil, Goia´s, Ribeiro, 2007). In this paper another species of Corumbataia is described, from the upper Rio Tocantins drainage on the Teresina de Goia´s, creek at highway GO-241, km 2, tributary Chapada dos Veadeiros formation. of Ribeira˜o dos Bois, tributary of Rio Parana˜, Rio Tocantins basin, 13u479390S, 47u179280W, 6 November 1996, W. R. Koch and K. M. Grosser. MATERIALS AND METHODS Measurements were made to the nearest 0.1 mm with digital Paratypes.—All from Brazil, Goia´s: MCN 13441, 6, 26.5– calipers under a stereomicroscope on the left side of 34.1 mm SL, MCP 41477, 5, 26.3–33.2 mm SL + 3 CS, 27.9– specimens following Boeseman (1968:fig. 5), with the 33.7 mm SL, collected with holotype; MCN 13147, 12, 21.3– exception of thoracic length, which was measured as the 27.7 mm SL, Cavalcante, Co´ rrego Dois Irma˜os, at highway GO- distance from the origin of pectoral-fin spine to the origin of 241, tributary of Ribeira˜o dos Bois, 13u479370S, 47u209040W, 2 the pelvic-fin spine. Additional measurements are suborbital August1996,W.R.Koch,P.C.C.Milani,andK.M.Grosser; depth, the distance between the lower margin of the bony MCN 13435, 58, 14.4–29.2 mm SL + 3 CS, 19.3–30.1 mm SL, orbit and the ventrolateral limit of the head and mandibular ANSP 187126, 5, 27.2–32.4 mm SL, MZUSP 94427, 5, 27.5– ramus, the transverse width of the dentary. Morphometric 29.3 mm SL, Teresina de Goia´s, creek at highway GO-241, km data are expressed as percents of standard length (SL), except 7, tributary of Ribeira˜o dos Bois, 13u479090S, 47u189510W, 6 subunits of the head which are expressed as percents of head November 1996, W. R. Koch and K. M. Grosser. length. Plate counts and nomenclature follow the schemes of serial homology proposed by Schaefer (1997). Vertebral Non-type material.—All from Brazil, Goia´s, Cavalcante: MCN counts include all vertebrae (including the first five 13136, 12, 25.2–36.8 mm SL, creek at Fazenda Veredas, 1 Laborato´rio de Ictiologia, Pontifı´cia Universidade Cato´lica do Rio Grande do Sul, Av. Ipiranga 6681, P.O. Box 1429, 90619-900, Porto Alegre, RS, Brazil; E-mail: [email protected]. Submitted: 13 March 2007. Accepted: 19 November 2007. Associate Editor: C. J. Ferraris. F 2008 by the American Society of Ichthyologists and Herpetologists DOI: 10.1643/CI-07-064 Copeia cope-08-03-08.3d 8/8/08 02:03:49 552 Cust # CI-07-064R1 Carvalho—New species of Corumbataia 553 Fig. 1. Corumbataia veadeiros, holotype, MCN 18571, male, 32.9 mm SL, creek at highway GO-241, km 2, tributary of Ribeira˜o dos Bois, Rio Tocantins basin, Teresina de Goia´s, Goia´s, Brazil. tributary of Rio das Almas, tributary of Rio Parana˜, Rio odontodes on the supraoccipital; Fig. 2), an infraorbital Tocantins basin, 13u509250S, 47u289080W; MCN 13141, 4, canal entering the infraorbital series via the sphenotic (vs. 20.5–27.3 mm SL, Rio das Almas at highway GO-241, infraorbital canal entering the infraorbital series via the 13u469360S, 47u259190W; MCN 13422, 1, 27.8 mm SL, Rio pterotic-supracleithrum), and by the color pattern of the das Almas at highway GO-241, 13u469360S, 47u259190W; caudal fin, which is composed of vertical dark bars (vs. MZUSP 40816, 4, 24.6–35.2 mm SL, small creek tributary of middle caudal-fin rays pigmented or one pair of hyaline Rio das Almas, 6 km north of urban area of Cavalcante, areas on the dark background of the ventral and dorsal 13u489S, 47u279W. lobes). Diagnosis.—Corumbataia veadeiros differs from its congeners Description.—Morphometrics and meristics given in Table 1. in its lack of a raised tuft of enlarged odontodes on the Adult body size large compared to other species of supraoccipital (vs. presence of a raised tuft of enlarged Corumbataia (maximum size 36.8 mm of SL). Body robust, Copeia cope-08-03-08.3d 8/8/08 02:03:49 553 Cust # CI-07-064R1 554 Copeia 2008, No. 3 Table 1. Morphometrics and Meristics of Corumbataia veadeiros. SD concave from ventral tip of snout to posterior border of 5 standard deviation, and n 5 number of specimens. head, straight from that point to origin of pelvic fin and straight posterodorsally inclined from that point to caudal- Holotype n Low High Mean SD fin base. Ventral surface of body transversely flattened at bases of pectoral and pelvic fins. Greatest body depth at Standard length (mm) 32.9 33 26.5 36.8 31.2 — dorsal-fin origin. Least body depth at end of caudal Percents of standard length peduncle. Body progressively narrower posteriorly, starting Head length 32.1 33 30.8 35.3 32.8 1.10 at pelvic-fin insertions. Head and snout broad. Snout Predorsal length 46.5 33 43.3 48.3 45.8 1.24 rounded in dorsal view. Interorbital region slightly convex. Dorsal-spine length 23.3 29 20.4 26.9 24.2 1.30 Upper margin of orbit not elevated. Eye small and Anal-spine length 20.1 26 18.4 22.4 20.7 0.95 positioned dorsolaterally. Iris diverticulum present. Pectoral-spine length 21.7 33 20.3 25.4 22.3 1.30 Pectoral fin of moderate size, I,6, distal fin margin slightly Pelvic-spine length 22.0 33 18.4 23.7 20.7 1.40 rounded. Tip of depressed fin reaching anterior one-third of Cleithral width 27.1 33 25.0 29.2 27.3 0.99 pelvic fin. Soft portion of pectoral-fin spine, comparatively Thoracic length 18.6 33 15.9 20.1 18.4 1.06 long, about one-fifth of spine length. Pectoral-fin axillary Abdominal length 23.0 33 20.3 25.3 23.1 1.21 slit present, small, and located below ventral margin of Body depth at dorsal-fin 20.7 33 20.0 24.1 21.4 1.02 cleithral process. Pelvic fin moderately short, I,5. Depressed origin fin reaching first anal-fin ray in males, but falling short of Caudal-peduncle length 27.6 33 25.4 31.8 29.3 1.51 that point in females. Adult males with fleshy flap along Depth of caudal 12.7 33 10.0 13.3 12.1 1.03 dorsal margin of first thickened pelvic-fin ray; flap wider peduncle basally and progressively reduced distally. Dorsal fin, II,7. Percents of head length Dorsal-fin spinelet rectangular in shape. Fin origin located at Snout length 57.5 33 49.2 60.2 54.8 2.85 vertical line through pelvic-fin origin. Anal fin I,5. First anal- Orbital diameter 15.4 33 15.0 18.3 16.5 0.91 fin pterygiophore not exposed anterior to anal-fin origin. Interorbital width 45.1 33 40.0 45.9 42.8 1.56 Adipose fin absent, some specimens with slightly pro- Head depth 59.4 33 52.6 59.6 57.0 1.64 nounced keel in adipose-fin region.