Bunocephalus erondinae, Cardoso, 2010

Cardoso, Alexandre R., 2010, Bunocephalus erondinae, a new species of banjo catfish from southern Brazil (Siluriformes: Aspredinidae), Neotropical Ichthyology 8 (3), pp. 607-607 : 607-

Bunocephalus erondinae , new species

Fig. 1

Holotype. MCP 40877, 82.9 mm SL, Brazil, Rio Grande do Sul State, Pelotas, canal São Gonçalo , laguna dos Patos system 31º46’18”S 51º18’04”W, 2 Feb 2005, M. Burs.

Paratypes. Brazil, Rio Grande do Sul State. MCP 40878, 17 , 1 c&s, 56.6-76.9 mm SL, collected with holotype; MCN 975, 1, 64.3 mm SL; MCN 976, 1, 60.2 mm SL; MCN 977, 1, 58.0 mm SL, rio Pardo, arroio Jacaré, tributary of rio Pardo , 5 Aug 1961, A. A. Lise. MCN 899, 1, 63.7 mm SL; MCN 900, 1, 61.0 mm SL, Porto Alegre, lago Guaíba, 18 Aug 1963, L. Buckup. MCN 3666, 1, 54.9 mm SL , Montenegro, rio Caí, near farm Chaleira Preta, 18 Oct 1977, O. Kelsch. MCN 7079, 3, 49.4-64.2 mm SL, Porto Alegre , lago Guaíba at Parque Náutico , 3 May 1985, H. Grosser. MCN 9456, 1, 62.3 mm SL, Porto Alegre , lago Guaíba at Cais do Porto , 15 Jul 1985, H. Grosser. MCN 12183, 1, 51.7 mm SL, Triunfo , rio Jacuí at Porto de Belinha or Manga , 8 Sep 1994, K. M. Grosser, W. R. Koch & R. Giacomini. MCN 14342, 5, 2 c&s, 53.0- 59.5 mm SL, Triunfo , rio Jacuí at Porto de Manga , 20 Oct 1994, K. M. Grosser & F. S. Stobbe. MCP 8966 , 1 c&s, 71.6 mm SL, Taquara, rio dos Sinos, 29 o 41’S 50 o 46’W, 26 Jan 1980, J. Casado. MCP 12030, 1 , 58.5 mm SL, Porto Alegre, rio Jacuí at ilha do Pavão , Apr 1988, E. Malabarba. MCP 14515, 1 , 56.9 mm SL, Porto Alegre, mouth of rio Jacuí , May 1988, E. R. Malabarba. MCP 14986, 1 , 62.2 mm SL, Guaíba, rio Jacuí near the ilha do Lage , 14 Dec 1989, E. Malabarba & A. Malabarba. MCP 15006, 1 , 59.6 mm SL, Porto Alegre at rio Jacuí delta, 1991, E. R. Malabarba, A. Malabarba & E. V. Malabarba. MCP 19079, 1 c&s, 67.1 mm SL, Cristal, rio Camaquã at farm Corticeira, 31 o 02’07”S 51 o 55’50”W, 10 May 1996, J. F. P. da Silva. MCP 19486, 1 , 60.6 mm SL, Triunfo, rio Taquari , 29 Oct 1996, M. Bruschi Jr. et al. MCP 33664, 7 , 1 c&s, 64.1-71.1 mm SL, Muçum, rio Taquari near mouth of rio Guaporé , 29 o 10’10”S 51 o 53’06”W, 5 Nov 2002, MCP team. MCP 33579, 1 , 60.6 mm SL, Muçum, rio Taquari near mouth of rio Guaporé , 29 o 10’10”S 51 o 53’06”W, 26 Sep 2002, MCP team. MCP 38710, 2 , 57.4 - 64.0 mm SL, Veranópolis, rio das Antas at channel of Monte Claro hydroelectric dam, 29 o 01’02”S 51 o 28’37”W, May 2005, J. Litini, V. Cappati & S. Rodrigues .

Diagnosis. Bunocephalus erondinae differs from its congeners by the bony epiphyseal bar very wide (vs. narrow; Fig. 2 ). Also B. erondinae is distinguished from B. doriae by the tip of the vertebral parapophysis 5 expanded with the shape of an axe (vs. not expanded, Fig. 2 ), metapterygoid round, as the width is equal (vs. metapterygoid elongate, as the width lesser than half of height, Fig. 3 ), well developed lamina on hypohyal and on the anterior ceratohyal bones (vs. little developed or absent, Fig. 4 ), first procurrent caudal-fin rays well developed (vs. vestigial, Fig. 5 ), and 32 vertebrae (vs. 34- 35); from B. aleuropsis by the absence of dark dots on the dorsal surface of the body (vs. present); from B. chaimaizelus by the maximum known standard length 83.1 mm SL (vs. 37 mm SL), and number of branched caudal-fin rays (7 vs. 8); from B. amaurus by the smaller interorbital width (24.1-29.2 vs. 32.2-32.4% HL); from B. colombianus by the larger predorsal length (45.6-51.2 vs. 44.6-44.8% SL); from B.

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610 A new species of banjo catfish from Southern Brazil coracoideus by the interorbital width (24.1-29.2 vs. 29.3-37.8% HL), and distance between the mental barbels (23.0-30.2 vs. 18.2-22.9% HL); from B. knerii by having larger coracoid process (13.4-20.5 vs. 8.6% HL), pectoral-fin spine length (24.7- 32.7 vs. 24.3% SL), interorbital width (24.1-29.2 vs. 30.0% HL), and caudal-peduncle length (31.0-37.3 vs. 43.2% SL); from B. larai by the predorsal length (45.6-51.2 vs. 41.2-42.8% SL), and length of coracoid process (13.4-20.5 vs. 9.2-10.1% SL); and from B. verrucosus by the head length (21.2-25.2 vs. 25.4- 27.8% SL), distance between the coracoid processes (19.7- 27.3 vs.15.4-19.3% SL), length of the coracoid process (13.4- 10.5 vs. 22.3-24.6% SL), head depth (44.6-60.0 vs. 77.6-92.7% HL), and interorbital width (24.1-29.2 vs. 30.4-35.1% HL).

Description. Morphometric data summarized in Table 1. Body shape, form and position of fins and barbels in Fig. 1 . Anterodorsal profile of body with slight depression above orbits that continues faintly anteriorly between ridges formed by lateral margins of mesethmoid, and straight posteriorly until near to end of supraoccipital. Profile of skull convex and ornamented by three dorsomedial bony knobs (at the supraoccipital, dorsal lamina of Weberian apparatus and the middle nuchal plate). Skull ornamentation reduced compared with some aspredinids (e. g. Bunocephalus verrocusus ). Posterodorsal profile of body straight from dorsal-fin origin to near base of caudal-fin, becoming slightly convex anteriorly to base of caudal-fin. Caudal peduncle slender, round in cross section, tapering to caudal-fin. Ventral body profile slightly convex from mouth to insertion of pelvic-fin; straight from end of pelvic-fin base to insertion of anal-fin; profile from anal-fin origin to base of caudal-fin slightly concave, becoming slightly convex at base of caudal-fin.

Head wide and depressed. Eyes small and positioned approximately laterally.Skin covering eye dense and pale.Anterior nostrils covered, located at tip of snout, projecting beyond upper lip. Posterior nostrils without flap, opening anteromedially to eye. Mouth subterminal, jaws and lips unequal; upper lip more

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prominent relative to lower lip. All barbels simple, unbranched; maxillary barbel reaching slightly last pectoral-fin spine insertion; posterolateral mental barbel twice as long as anteromedial barbel. Opercular opening reduced to small valvular slit just anterior to pectoral-fin spine insertion.

Dorsal-fin rays i,4. Dorsal-fin spinelet absent. Last dorsalfin ray not adnate to body, membrane between last dorsalfin ray and body small. Pectoral-fin rays I,5. Pelvic-fin rays i,5, fourth ray longest but not reaching anal-fin origin; pelvic splint absent. Adipose fin absent. Anal-fin rays ii,5-ii,7, membrane between last anal-fin ray and body small. Caudalfin rays i,8,i; rounded. Caudal-fin unbranched rays shorter than branched rays; two procurrent rays on upper and lower lobe, respectively. Lateral-line canal complete but rarely reaching caudal-fin origin. Total vertebrae 32.

Color in alcohol. Head light brown; body with three dark brown saddles on a light brown base; first saddle at dorsalfin, and two saddles on posterior body, saddles may fuse and expand ventrally and laterally to give appearance of light brown dorsal patches on dark brown base; anterior ventral surface much lighter than dorsal surface; pectoral-fin brown with light distal margin; ventral and anal fins whitish with dark blotches; and dorsal and caudal-fins dark gray with light distal margin. All barbels brown with dark blotches.

Distribution. Known from several tributaries to the laguna dos Patos system, Rio Grande do Sul, Brazil ( Fig. 6 ).

Etymology. The specific name, erondinae , is given in memory to my mother Erondina Rodrigues Cardoso.

Figures

Fig. 1. Bunocephalus erondinae, MCP 40877, holotype, 82.9 mm SL, canal São Gonçalo, laguna dos Patos system, Pelotas, Rio Grande do Sul, Brazil.

Fig. 2. Dorsal view of neurocranium and Weberian complex of (a) Bunocephaluserondinae, paratype,MCP 8966 (71.6 mmSL) and of (b) B. doriae, MCP 13176 (50.9 mm SL).ACF, anterior cranial fontanel; CC, complex centrum; F, frontal; ME, mesethmoid; PCF,posteriorcranial fontanel; PTE,pterotic; SOC, supraoccipital; SPH,sphenotic; SU, supracleithrum;VP 5,ventral parapophysis 5; andWL, Weberian lamina.Scale bar = 1 mm.

Fig. 3. Dorsal view of the quadrate and metaperygoid of (a) Bunocephalus erondinae, paratype, MCP 33664 (68.5 mm SL) and of (b) B. doriae, MCP 13176 (50.9 mm SL). MET, metapterygoid, and QUA, quadrate. Scale bar = 1 mm.

Fig. 4. Dorsal view of the hyoid bar of (a) Bunocephalus erondinae, paratype, MCP 33664 (68.5 mm SL) and of (b) B. doriae,MCP 13176(50.9mmSL).AC, anteriorceratohyal;HYP, hypohyal; and PC, posterior ceratohyal. Scale bar = 1 mm.

Fig. 5. Lateral view of the caudal skeleton of (a) Bunocephalus erondinae, paratype, MCP 33664 (68.5 mm SL) and of (b) B. doriae, MCP13176 (50.9 mm SL).Scale bar = 1 mm.

Fig. 6. Map of RioGrande do Sul, Brazil, and Uruguayshowing the distribution of Bunocephalus erondinae. Each square represents one or more collecting localities. “T” indicates the type-locality.