Hypostomus velhochico, Zawadzki & Oyakawa & Britski, 2017

Zawadzki, Cláudio H., Oyakawa, Osvaldo T. & Britski, Heraldo A., 2017, Hypostomus velhochico, a new keeled Hypostomus Lacépède, 1803 (Siluriformes: Loricariidae) from the rio São Francisco basin in Brazil, Zootaxa 4344 (3) : -

Hypostomus velhochico , new species

( Figs. 1 , 2 and 3 , Table 1)

Holotype. MZUSP 47327 , 93.4 mm SL, municipality of São João das Missões, unknown name stream, tributary of rio Itacarambi , 14°53’6.8”S 44°5’20.4”W, 21 Jul 1994, N.A. Menezes, O.T. Oyakawa, J.C. Garavello & R.L. de Moura.

Paratypes. All from Brazil, Minas Gerais State (except when noticed), rio São Francisco basin: ICT-UFMG 2901, 1, 95.8 mm SL, municipality of Felixlândia, rio Paraopeba, at the confluence to Três Marias reservoir, 18°51’43.71”S 44°53’55.13”W, 4 Oct 2016, G.V. Torquato & W.A. dos Santos . LBP 8284, 6, 43.8–84.3 mm SL, municipality of Jaíba, rio Verde Grande , 15°19’24”S 43°39’52”W, 13 May 2009, C. Oliveira, G.J.C. Silva, F.F. Roxo & T.N.A. Pereira . MCNIP 1307, 1, 73.9 mm SL, municipality of São João da Missões, rio Itacarambi, 14°52’46”S 44°05’00”W, 15 Jul 1993, R.E. Reis, J.P. Silva, E.L. Pereira & S. Schaefer. MCNIP 1795 , 1 , 125.3 mm SL, municipality of Curvelo, at the border to Pompéu, rio Paraopeba , just downstream to Retiro Baixo Dam , 18°52’36”S 44°46’49”W, 11 Jan 2017, G.V. Torquato & V.A. dos Santos & I.S. Penido . MCP 16664, 1 , 66.8 mm SL, municipality of Montalvânia, rio Poções, em São Sebastião dos Poções , tributary of rio Coxá , 14°32’S 44°24’W, 16 Jul 1993, R.E. Reis, J.P. Silva, E.L. Pereira & S. Schaefer . MCP 16672, 2, 46.2–63.4 mm SL, municipality of São João das Missões, divide between municipalities of Itacarambi and Manga , rio Itacarambi , 14°52’46”S 44°05’00”W, 15 Jul 1993, R.E. Reis, J.P. Silva, E.L. Pereira & S. Schaefer . MCP 16689, 1 , 91.4 mm SL, municipality of Bom Jesus da Lapa , Bahia State, rio São Francisco, 13°15’12”S 43°25’20”W, 16 Jul 1993, R. E. Reis, J.P. Silva, E.L. Pereira & S. Schaefer . MCP 28344, 7, 18.4–24.8 mm SL, municipality of Paracatu, córrego Rico, road from Paracatu to João Pinheiro , tributary of rio Paracatu , 17°18’15”S 46°46’16”W, 24 Jan 2001, C.A. Lucena, J.P. Silva, E.L. Pereira & A. Cardoso . MCP 33816, 3, 62.4–82.6 mm SL, divide between municipalities of Januária and Itacarambi, Bahia State, rio Peruaçu , 15°06’48”S 44°10’04”W, 19 Mar 2003, M.F.G. Brito & B.P. Nogueira . MNRJ 15755, 2, 41.3–47.9 mm SL, municipality of Itacarambi, rio Peruaçu , no coordinates available, 18 Aug 1990, D.F. Moraes Jr. & J.C. de Oliveira . MNRJ 16102, 2, 42.8–68.7 mm SL, municipality of Janauba, Cachoeirinha village, rio Verde Grande , no coordinates available, 24-30 Sep 1990, D.F. Moraes Jr., L.C. Alvarenga & C. Ricci . MNRJ 17358 , 1 , 109.9 mm SL, municipality of Manga, rio São Francisco, at Mocambinho (artificial channel on the rigth bank of the river), no coordiantes available, 20 Dec 1989, J.C. de Oliveira . MZUSP 47450 , 2 , 133.9 –136.0 mm SL, divide between municipalities of Montes Claros and Francisco Sá, rio Verde , 16°39’7”S 43°42’55”W, 23 Jul 1994, N.A. Menezes, O.T. Oyakawa, J.C. Garavello & R.L. de Moura . MZUSP 57401, 2, 62.3–64.5 mm SL, municipality of São Desidério, rio São Desidério , under the bridge in the BR 135, 12°20’56”S 44°59’32”W, 7 Jul 1998, O.T. Oyakawa, A. Akama & V. Garutti . MZUSP 57561 , 3 , 29.0– 43.8 mm SL, rio Verde Grande, in the road from Montes Claros to Janaúba , 16°39’1”S 43°42’49”W, 20, Jul 1993, R.E. Reis, J.P. Silva, E.L. Pereira & S. Schaefer . MZUSP 73759 , 1 , 74.5 mm SL, divide between municipalities of Santo Hipólito and Corinto, rio das Velhas , 18°24’56”S 44°11’20”W, 13 Dec 1999, C.B.M. Alves & P.S. Pompeu . MZUSP 73816 , 1 , 83.4 mm SL, municipality of Presidente Juscelino, rio Cipó , 18°41’04”S 43°59’18”W, 13 Dec 1999, C.B.M. Alves & P.S. Pompeu . MZUSP 94586 , 1 , 102.6 mm SL, municipality of Santa Maria da Vitória, Bahia State, rio Corrente , 13°14’5.9”S 44°23’30.8”W, 0 6 May 2007, O.T. Oyakawa, J.M. Cunha & G.M.T. Mattox . MZUSP 94590 , 1 , 91.7 mm SL, municipality of Descoberto, Bahia State, riacho da Lagoa Grande, tributary of rio Corrente, in the road from Descoberto to Colônia Formoso, 13°33’41”S 44°17’37”W, 0 7 May 2007, O.T. Oyakawa, J.M. Cunha & G.M.T. Mattox . MZUSP 94592 , 1 , 71.6 mm SL, municipality of Itacarambi, rio São Francisco , 15°06’05”S 44°05’35”W, 0 7 May 2007, O.T. Oyakawa, J.M. Cunha & G.M.T. Mattox . MZUSP 120450, 1 , 106.7 mm SL, municipality of Casa Nova, Bahia State, rio Braúna, at confluence to Sobradinho reservoir, 9°23’02”S 41°07’07”W, 27 Jan 2008, L. Stegmann, N.C.L. dos Santos, E.M. Junior, A.E. de Lima & B.D.F. da Costa . MZUSP 120451, 1 , 103.8 mm SL, municipality of Pilão Arcado, Bahia State, rio Morro dos Mocós, at confluence to Sobradinho reservoir, 10°16’30”S 42°24’51” W, 17 Mar 2008, C.A. Collier, G.C. Pinto, J.J. Freitas Neto, B.D.F. da Costa & A.E. de Lima . MZUSP 120452, 1 , 107.8 mm SL, municipality of Sento Sé, Bahia State, riacho das Andorinhas, at confluence to Sobradinho reservoir, 9°44’33”S 41°59’51”W, 8 Nov 2007, F.A.G. Neto, G.A. Pinto, N.C.L. dos Santos, B.D.F. da Costa & A.V. Calado Neto . NUP 12064, 1 , 66.6 mm SL, municipality of Presidente Juscelino, rio Cipó, tributary of rio das Velhas , 18°41’04”S 43°59’18”W, 18 Aug 2001, P.S. Pompeu & C.B.M. Alves . NUP 12065, 92.6 mm SL, municipality of Pirapora, rio das Velhas, tributary of rio São Francisco , 17°14’47”S 44°49’16”W, 27 Jun 2007, P.S. Pompeu & C.B.M. Alves . NUP 12066, 1 , 82.8 mm SL, municipality of Santana do Pirapama, rio das Velhas , 18°53’22”S 44°08’15”W, 13 Jan 2007, P.S. Pompeu & C.B.M. Alves . NUP 12067, 1 , 80.2 mm SL, municipality of Santana do Pirapama, rio das Velhas , 19°31’50”S 43°55’33”W, 29 Jun 2000, P.S. Pompeu & C.B.M. Alves . NUP 16260, 1 , 51.1 mm SL, municipality of Formoso, Parque Nacional Grande Sertão Veredas, rio Cariranha , tributary of rio Preto , 15°07’10”S 45°45’21”W, 28 Apr 1999, M.L. Ribeiro, V. Perdigão & E.C. Lopes . ZUEC 8518 , 1 , 67.1 mm SL, municipality of Cabeceira Grande, rio Preto , downstream Queimados falls, rio Paracatu basin, 16°12’37”S 47°17’19”W, 24 Sep 1997, M.L. Ribeiro, V. Perdigão & E.C. Lopes.

Diagnosis. Hypostomus velhochico is distinguished from the species of the H. cochliodon group by having slender viliform bicuspid teeth (vs. robust spoon-shaped teeth) and by having dentaries angled to each other more than 90 degrees (vs. dentaries angles from 80 to 90 degrees); from the remaining congeners except H. affinis , H. ancistroides , H. aspilogaster , H. boulengeri , H. carinatus , H. commersoni , H. corantijni , H. crassicauda , H. delimai , H. faveolus , H. gymnorhynchus , H. hemiurus , H. hoplonites , H. micromaculatus , H. pantherinus , H. paucimaculatus , H. piratatu , H. plecostomus , H. tapijara , and H. watwata , by having conspicuous keels along the five lateral series of plates (vs. lacking conspicuous keels). The new species is distinguished from H. corantijni , H. crassicauda , H. gymnorhynchus , H. hemiurus , H. micromaculatus , and H. paucimaculatus by having roundish dark spots on the body (vs. slightly transverse dark spots, see Weber et al., 2012, figs. 8 and 9). The new species is distinguished from H. carinatus , H. hoplonites and H. watwata by having one plate on the posterior border of supraoccipital (vs. presence of five to seven plates—see Fig. 3 , pg. 77 in Zawadzki et al., 2013). Hypostomus velhochico is distinguished from H. affinis , H. ancistroides , H. aspilogaster , H. commersoni and H. tapijara by having shorter caudal peduncle with 24 to 26 plates at the median lateral series (vs. longer caudal peduncle, with 28 to 31 in H. affinis , data from Mazzoni et al., 1994; 27 to 28 in H. ancistroides , unpublished data of C.H. Zawadzki from 20 specimens from the rio Tietê basin—see Comparative material examined; 29 to 31 in H. aspilogaster and 28 to 30 in H. commersoni , both records from Reis et al., 1990; 28 to 31 in H. tapijara , data from Oyakawa et al., 2005); from H. delimai and H. faveolus by having dark spots (vs. having pale spots); from H. boulengeri , H. pantherinus and H. plecostomus it is distinguished by having dark spots at the same size as the eye pupil on the head and dark spots of the similar size on the trunk and fins (vs. spots increasing in length from head to posterior region of trunk and fins, smaller than eye pupil on head and increasing in size and usually becoming larger than eye pupil towards posterior region of body and fins); from H. piratatu by having dark spots horizontally aligned along lateral series of plates (vs. dark spots unorganized—see Weber, 1986, fig. 3, pg. 988), and by attaining smaller size, up to 140 mm SL (vs. attaining larger size up to 275 mm SL—data from Weber, 1986); from H. pusarum by having raised supraorbital and interorbital region straight to concave (vs. supraorbital plain and interorbital region convex), pectoral-fin spine depressed even on larger specimens (vs. pectoral-fin spine rounded in larger specimens), by attaining smaller size, up to 140 mm SL (vs. attaining larger size up to 180 mm SL from specimens of the type locality NUP 14685 and up to 220 mm SL in specimens from the rio São Francisco basin NUP 13973 and NUP 13974; see data in Comparative material examined), and by having strongly-developed odontodes along lateral keels (vs. moderately-developed odontodes; Fig. 2 ).

Description. Morphometric data in Table 1. Overall view of body in Fig. 1 . Head broad, moderately depressed and slightly compressed. Snout and anterior profile of head rounded in dorsal view. Eye of moderate size, laterally positioned. Dorsal margin of orbit moderately raised. Greatest body width at cleithrum, narrowing from dorsal-fin region to caudal-fin origin. Dorsal profile of head straight from snout tip to vertical through interorbital region, forming angle of 45° with ventral region of head; slightly convex from that point to dorsal-fin origin; straight from that point to adipose fin and concave from adipose fin to procurrent rays of dorsal fin. Ventral profile almost straight from snout tip to insertion of pelvic-fin unbranched ray; slightly straight from pelvic-fin insertion to first ventral caudal-fin procurrent ray. Caudal peduncle compressed, somewhat ellipsoid in cross section on its whole extension. Plates along the mesethmoid forming a longitudinal bulge from snout tip to nares, more conspicuous in specimens up to 80.0 mm SL (e.g. NUP 12066). Supraoccipital bone with slightly-developed median ridge; its short posterior process bordered by single plate. Conspicuous ridge originating lateral to nares, passing through supraorbital, and extending along dorsal portion of pterotic-supracleithrum. Opercle moderate in size, with thin skin layer surrounding its edges. Oral disk round, moderate in size; its margins fringed. Lower lip not reaching transverse line through gill openings; ventral surface covered with numerous small papillae decreasing in size distally. Maxillary barbel slightly smaller than eye diameter; mostly free from lower lip. Odontodes present on anterior surface of upper lip, just below snout. Median buccal papilla present and well developed. Dentaries moderate to strongly angled, averaging from 80° to 90° between left and right dentary rami. Teeth viliform, bicuspid with lateral cusp smaller than mesial cusp; crowns bent ventrally.

Body covered with five rows of dermal plates with moderately-developed odontodes, except on base of dorsal fin and small naked area on snout tip. Predorsal region with very slight median keel. Dorsal series of plates with very slight keels. Mid-dorsal, median, and mid-ventral series with relatively well-developed keels. Median series bearing continuous lateral line. Mid-ventral series strongly angled from first to fourth or fifth plates. Ventral series without keel, but sharply bent ventrally on caudal-peduncle region. Ventral surface of head covered with platelets, except for the region beneath lower lip. Abdomen covered with minute platelets in specimens larger than 80 mm SL, with exception of very small areas around pectoral- and pelvic-fin insertions and at urogenital opening. Distal portion of pterygiophore exposed.

Dorsal fin II,7, its origin at vertical through midpoint between pectoral- and pelvic-fin insertion, or slightly posterior to that point, first spine present as V -shaped spinelet. Distal margin of dorsal fin straight; tip of last dorsalfin ray almost reaching adipose-fin spine. Adipose-fin spine compressed and slightly curved inward. Pectoral fin I,6, its distal border convex. Pectoral-fin spine slightly curved inward, covered with moderately developed odontodes, more developed on its distal portion, particularly in larger specimens. Tip of adpressed pectoral fin reaching to basal one-third to one-fourth of adpressed pelvic-fin spine. Pelvic fin i,5, its distal border straight to slightly convex; its adpressed unbranched ray surpassing anal-fin origin. Anal fin i,4, its tip reaching the fifth to sixth plate after its origin. Rays of anal fin progressively increasing in length posteriorly, third branched ray usually the longest. Caudal fin i,14,i, its margin falcate, with ventral lobe longer than dorsal.

Color in alcohol. Overall ground color of dorsal and ventral regions of body and fins yellowish-brown ( Fig. 1 ). Head, trunk and fins covered by well-defined and moderately-set dark brown spots except on lower lip. Spots roundish and homogeneously-sized along longitudinal axis of body, usually slightly smaller than eye pupil. Dark spots sometimes horizontally aligned along each lateral series of plates (e.g. LBP 8284). Ventral surface of body with conspicuous spots, except in some specimens up to 70 mm SL (e.g. MCP 16664). All fins with conspicuous dark brown spots, except caudal fin on specimen MCP 33816, 82.6 mm SL. Dorsal fin with spots usually forming four to five transverse rows. Most specimens with five faded oblique dark bars on dorsum, first bar on posterior portion of head, stronger at middle of orbit, second bar at first dorsal-fin branched rays, third bar at last dorsal-fin branched ray, fourth bar at anterior region of adipose fin and fifth at procurrent caudal-fin rays.

Color in life. Color pattern of living specimens similar to preserved ones, except for more brownish background and black and more conspicuous spots ( Fig. 3 ).

Sexual dimorphism. No sexual dimorphism was observed among the specimens.

Distribution. Hypostomus velhochico is known from several localities along the rio São Francisco basin ( Fig. 4 ). The species was found from the upper stretches of the basin as the rio Cipó, a tributary of rio das Velhas in Minas Gerais State; and from the rio Preto, a tributary of the median stretch as the rio Paracatu in Distrito Federal State; to lower stretches of the basin as the rio Verde Grande, rio Coxá basin, as well as in rivers draining to the Sobradinho reservoir, in the Bahia State.

Ecological notes. Hypostomus velhochico was found in low current stretches with bottom composed by sand and clay (with predominance of clay). The average width of the river stretches was about 20 meters and depth ranging from 1.0 to 2.0 meters. Margins with arboreal-shrub vegetation typical of Cerrado biome. Currently these banks are usually antropically fragmented. The new species occurred syntopically to Acestrorhynchus lacustris , Astyanax fasciatus , Hypostomus francisci , Megaleporinus obtusidens , Megaleporinus reinhardti , Schizodon knerii , and Serrasalmus brandtii .

Etymology. The specific epithet, velhochico , is in reference to the rio São Francisco, tenderly called by locals as “Velho Chico” [Old Chico]. A noun in apposition.

Figures

FIGURE 1. Hypostomus velhochico, MZUSP 47327, 93.4 mm SL, holotype, Brazil, Minas Gerais, São João das Missões, stream tributary of rio Itacarambi, rio São Francisco basin.

FIGURE 2. Above: Hypostomus velhochico, MZUSP 47450, 136.0 mm SL, paratype, rio Verde, rio São Francisco basin. Below: Hypostomus pusarum, NUP 14685, 179.5 mm SL, topotype, rio Ceará-Mirim. Green and red boxes lead to lateral view inserts showing differences in pectoral-fin spine and keeled lateral plate series, respectively.

FIGURE 3. Live coloration of Hypostomus velhochico MCNIP 1795, paratype, 125.3 mm SL. Brazil, Minas Gerais State, rio Paraopeba, rio São Francisco basin. Photo: Gabriel Torquato.

FIGURE 4. Geographical distribution of Hypostomus velhochico; red star = type-locality.