Cyanocharax lepiclastus Malabarba, Weitzman & Casciotta, 2003

Malabarba, Luiz R. & Weitzman, Stanley H., 2003, Description Of A New Genus With Six New Species From Southern Brazil, Uruguay And Argentina, With A Discussion Of A Putative Characid Clade (Teleostei: Characiformes: Characidae), Comun. Mus. Ciênc. Tecnol. PUCRS 16 (1), pp. 67-151 : 120-127

Cyanocharax lepiclastus Malabarba, Weitzman & Casciotta , new species

(Figs. 1,33-38, Table 5 )

Diagnosis. Cyanocharax lepiclastus is distinguished from C. dicropotamicus , C. itaimbe , C. alburnus and C. tipiaia by the greater number of scales covering the basal portion of anal-fin rays (13 -20 versus 7- 13), greater number of branched anal-fin rays (24-29, x̄= 26.2, n = 133, versus 22-27, x̄= 23.9, n = 88 in C. itaimbe ; 22-28, x̄ = 24.6, n = 130 in C. dicropotamicus ; 21-23, v = 22.3, n = 15 in C. tipiaia ; and 20-23 in C. albur ­ nus), absence of unpigmented area along distal tip of anal fin anterior lobe (unpigmented area present in C. dicropotamicus and C. itaimbe ), and in having anal-fin origin positioned nearly along vertical through dorsal-fin origin (versus clearly posterior to vertical through dorsal-fin origin in C. dicropotamicus , C. alburnus and C. itaimbe ). The nearly straight distal border of anal fin of mature males of C. lepiclastus distinguishes it from C. dicropotamicus , C. alburnus , and C. itaimbe that have distal border of anal fin concave, and C. macropinna and C. alegretensis that have distal border of anal fin convex.

Description. Morphometric data given in Table 5 . Body moderately elongate and compressed. Predorsal body profile convex, usually with a concavity at nape in large specimens. Dorsal body profile nearly straight from dorsal fin to caudal peduncle. Ventral body profile convex from snout tip to anal-fin origin. Nearly straight in females and slightly convex in mature males along anal-fin base. Ventral and dorsal borders of caudal peduncle slightly concave.

Head small (21.0-24.5% of SL). Eyes large (39.1 -48.5% of HL). Max ­ illa positioned at angle of 45 degrees relative to long body axis. Posterior tip of maxilla usually reaching to vertical through anterior border of pupil.

Two series of premaxillary teeth. Teeth of outer series usually tricuspid, smaller than those of inner series, numbering 3 to 5. Four or five teeth with 3 to 5 cusps in inner series. Three to eight usually tricuspid maxillary teeth. Dentary with three large anterior teeth followed by one mediumsized teeth and 7 to 10 smaller ones, ranging from 3 cusps to conical, from anteriormost to posteriormost teeth. Anterior larger dentary teeth with 3 to 5 cusps. Second dentary tooth shorter and inserted at lower position in jaws, in such a way that tip of its longest cusp reaches only as high as tip of second largest cusp of first and third dentary teeth ( Fig. 38 ).

Dorsal-fin rays ii,7-8 (x = 7.9, n = 20). Dorsal-fin origin near middle ofbody length. Adipose fin dorsal to posterior anal-fin ray insertion.

Anal-fin rays iv-v, 24-29 (x = 26.2, n = 133). Anal-fin origin nearly ventral to dorsal-fin origin at middle of body length. Anal-fin distal border concave in females and juveniles, convex or nearly straight in mature males. Anal-fin rays of males with small retrorse bony hooks present on mid distal length of longest unbranched ray and usually anterior 13 to 15 branched rays. Minute hooks may be present along third distal portion of some remaining rays. Hooks mostly present on posterior branches of rays and posterior border of lepidotrichia. Usually one pair of bony hooks per ray segment; two pairs rarely occur on 1, 2 or 3 anterior branched rays.

Pectoral-fin rays i, 9- 11 (x̄ = 9.6, n = 20). Distal ends of longest rays extend posterior to pelvic-fin insertion in both males and females. Pelvic-fin rays i, 6 (n = 20). Pelvic-fin origin anterior to dorsal-fin origin. In females distal ends of longest rays may or may not reach anal-fin origin. In mature males distal ends of longest rays reach anal-fin origin. Pelvic fins with ventromedial, usually unpaired retrorse bony hooks on first unbranched and all branched rays in sexually mature males. Principal caudal-fin rays 10/9.

Scales cycloid. Lateral line irregular, never complete. Lateral line usually with anterior series of 9 to 14 pored scales (x̄ = 10.6, n = 34) followed by a median non-perforated series of 9 to 22 scales, a median posterior perforated series of 3 to 18 scales, and sometimes a posterior nonperforated series of usually 1 or 2 (most rarely 4 to 5) scales. Scale pattern extremely variable, with more than four alternate series of perforated ver ­ sus non-perforated scales in some specimens. Total number of scales in lateral-line row 37-39 (x̄= 37.8, n = 38). Scale rows between dorsal-fin origin and lateral line 6-7 (x̄ = 6.1, n = 33; 5 in one specimen). Scale rows between lateral line and pelvic-fin origin 4-5 (x̄ = 4.7, n = 32). Predorsal scales 11- 13 (x̄ = 12.1, n = 24). Males and females with a sheath of scales on anal-fin base consisting of one row with 13 -20 small scales, covering bases of unbranched rays and first 14 to 20 branched rays.

Vertebrae 35-37 (x̄= 36.3, n = 26), including Weberian apparatus and posterior half centrum (counts taken from x-ray negatives from MCP 15200).

Color in alcohol. Figs. 33-34 , 36-37 . Body pale brownish yellow in specimens preserved in formalin long enough to destroy guanine pigment. Lateral body stripe broad and dark posteriorly, becoming pale anterior to dorsal-fin origin. Lateral body stripe broad and silvery in freshly preserved specimens. Dark humeral spot small, vertically elongated and centered on fourth scale of scale row just dorsal to lateral line. Exposed borders of scales of dorsal portion of body delineated by dark chromatophores. Caudal fin slightly dark pigmented in mature males. Dorsal and anal fins darkly pigmented, except for distinct unpigmented area at tip of dorsal fin. Distal border of anal fin more intensely darkly pigmented. Adipose fin weakly pigmented. Head black to gray dorsally, especially dark near nape. Sides of head and opercles silvery where guanine pigment not destroyed by formalin, sides ofhead otherwise whitish yellow.

Color in life. Described from photos taken just after fixation formalin ( Fig. 35 ). Body light pale brownish yellow. Sides of head and belly silvery white. Lateral body stripe broad and silvery light blue from humeral spot to caudal-fin base. Clearly discernible vertical small black humeral spot present. Exposed borders of scales of dorsal portion of body delineated by dark chromatophores. Caudal fin slightly dark pigmented. Dorsal and anal fins dusky, except for distinct unpigmented area at tip of dorsal fin. Nar ­ row portion of distal border of anal fin intensely dark pigmented. Adipose fin weakly pigmented by dark chromatophores.

Sexual dimorphism. Male specimens of C. lepiclastus differ from fe ­ males in the nearly straight distal border of the anal fin (versus concave in females), by the presence of anal and pelvic-fin hooks, and slightly larger pelvic-fin ray lengths ( Table 5 ).

Etymology. Lepi is from the Greek lepis meaning scale and clastus from the Greek klastos meaning broken in pieces. It is in reference to the unusual irregular alternate sets of pored and unpored scales in the lateral line.

Ecological notes. MCP 25751, MCP 16381, and MCP 14557 were collected in clear turbid water, with rocks, stones, sand and mud on the bottom, in both medium water velocities and still waters.

Distribution. This species occurs in the uppermost section of the rio Uruguay from the headwaters of rio Pelotas and rio Canoas to arroio Lageado União in Brazil, and in the eastern portion of Misiones Province in the North-East of Argentina ( Fig. 1 ).

Holotype: MCP 25751 , male, 44.5 mm SL, rio Dourados , Linha V árzea, on road between Severiano de Almeida and Aratiba, Severiano de Almeida, Rio Grande do Sul, Brazil; 12 Dec 1992.

Paratypes, all from rio Uruguay drainage , Santa Catarina, Brazil: MCP 12972 (3, 36.5-39.5 mm SL), rio Jacutinga , on road Seara - Concordia (BR 283), Concordia; 8 Dec 1988 . MCP 12790 (2, 37.6-38.9 mm SL), rio Canoas , on road Abdom Batista - Anita Garibaldi, Campos Novos; 11 Nov 1988 . MCP 12374 (6, 34.3 -41.6 mm SL), rio Canoas , on road Abdom Batista-Anita Garibaldi, Campos Novos; 9 Sep 1988 . MCP 14550 (4, 32.5-35.1 mm SL), rio Canoas , on road Abdom Batista-Anita Garibaldi, Campos Novos; 29 Jun 1988 . MCP 12373 (2 c&s), rio Canoas , Passo do Canoas, on road Tupitinga ‒ Celso Ramos, Campos Novos; 11 Sep 1988 . Rio Grande do Sul, Brazil: MCP 16381 (4, 39.8-41.8 mm SL), MCP 16398 (2, 30.7-31.3 mm SL), collected with holotype . MCP 12924 (15: 4 c&s, 23.5-39.5 mm SL), MNRJ 23842 (8, 25.0- 37.8 mm SL), rio Pelotas , on road Anita Garibaldi - Pinhal da Serra, Esmeralda; 11 Dec 1988 . MCP 13362 (20, 18.5-34.4 mm SL), rio Pelotas , Passo da Pedra da Ovelha, on road Anita Garibaldi-Pinhal da Serra, Esmeralda; 20 Feb 1989 . MCP 12977 (14, 25.5 -35.6 mm SL), rio Uruguay , mouth of rio Canoas and rio Pelotas ; 10 Dec 1988 . MCP 12470 (4, 30.9-37.5 mm SL), rio Ligeiro , on road Maximiliano de Almeida - Marcelino Ramos; 3 Oct 1988 . MCP 13313 (9, 26.6-35.8 mm SL), rio Ligeiro , on road Maximiliano de Almeida-Marcelino Ramos (RS 127); 17 Feb 1989 . MCP 12286 (5, 16.4- 32.7 mm SL), rio Uruguay , bridge of road BR 153, limit between Rio Grande do Sul and Santa Catarina; 17 Aug 1988 . MCP 15200 (9, 28.4- 44.7 mm SL), USNM 357243 (9), MZUSP 82259 (9), creek on road RS 135, between Getúlio Vargas and Erexim ; 17 Nov 1983 . MCP 14557 (29: 4 c&s, 30.8-43.4 mm SL), arroio Lageado União, Linha dos Lima, Palmitinho; 22 Dec 1985 . Misiones, Argentina: AI 103 (5), arroyo Fortaleza, tributary of arroyo Yabotí-Guazú (26°45 ’ S, 54° 10 ’ W), February 2001 .

Non-type specimens . Rio Grande do Sul, Brazil: MCP 12285 (3), rio Dourados, Mariano Moro, 17 Aug 1988 . MCP 22686 (105.), rio Dourados, on road between Erexim and Dourados, Erexim; 8 Apr 1999 . MCP 12284 (20), rio Pelotas, Pinhal da Serra, Esmeralda; 20 Aug 1988 . MCP 12122 (7), rio Ligeiro, near boat, 15.5 km from Sao Joao da Urtiga; 25 May 1988 . MCP 12121 (8), rio Ligeiro, on road Maximiliano de Almeida-Marcelino Ramos ( RS 127); 18 Feb 1989 . MCP 23186 (240), arroio Taquari, about 10 Km South of Vila Kramer, Sao Francisco de Assis; 8 May 1999 .

Figures

Figure 1. Map of southern Brazil, Uruguay and eastern Argentina, showing the distribution of examined specimens of Cyanocharax alegretensis, C. dicropotamicus, C. itaimbe, C. lepiclastus, C. macropinna, and C. tipiaia. The detailed portion of the map includes, from North to South, the rio Araranguá, rio Mampituba, rio Três Forquilhas, and rio Maquiné drainages.

Figure 33. Cyanocharax lepiclastus, male, 45.2 mm SL, arroio Lageado Uniao, Linha dos Lima, Palmitinho, Rio Grande do Sui, Brazil (MCP 14557).

Figure 34. Cyanocharax lepiclastus, female, 38.5 mm SL, same locality as in Fig. 33 (MCP 14557).

Figure 35. Cyanocharax lepiclastus, holotype, male, MCP 16381, rio Dourados, Linha Várzea, on the road between Severiano de Almeida and Aratiba, Severiano de Almeida, Rio Grande do Sul, Brazil. Photograph taken just after fixation in formalin by Peter Wimberger,

Figure 36. Cyanocharax lepiclastus, male, 49.5 mm SL, rio Dourado, on the road between Erechim and Dourado, Erechim, Rio Grande do Sul, Brazil (MCP 22686).

Figure 37. Cyanocharax lepiclastus, female, 49.5 mm SL, arroio Taquari, about 10 Km S of Vila Kramer, Sao Francisco de Assis, Rio Grande do Sul, Brazil (MCP 23186).

Figure 38. Jaws and teeth of Cyanocharax lepiclastus (MCP 16382, 43.2 mm SL). A-B - Maxilla and detailed view of teeth; C-D - Premaxilla and detailed view of teeth; E-F - Dentary and detailed view of teeth.

Tables

Table 5. Morphometries of Cyanocharax lepiclastus, new species. Standard length is expressed in mm; other measurements through head length are percentages of standard length; the last four entries are percentages of head length. All specimens are from upper rio Uruguay. Described ranges include measurements of the holotype MCP 25751, male, and following paratypes: MCP 12373 (2); MCP 12374 (6); MCP 12470 (3); MCP 12790 (2); MCP 12924 (9); MCP 12972 (1); MCP 12977 (8); MCP 13313 (6); MCP 13362 (15); MCP 14550 (4); MCP 14557 (26); MCP 15200 (21).

Character	holotype	n	low	high	x
Standard length (mm)	44.5	103	26.3	46.3	37.6
Snout to anal-fin origin	52.1	103	52.1	58.8	55.4
Snout to dorsal-fin origin	53.0	103	50.6	57.9	53.5
Snout to pelvic-fin origin	41.6	103	38.6	44.6	42.0
Dorsal-fin base length	11.9	103	8.6	12.1	10.4
Anal-fin base length	36.9	103	32.8	40.0	35.9
Caudal peduncle length	12.4	103	10.0	13.9	12.1
Caudal peduncle depth	10.8	101	9.2	12.2	10.6
Depth at dorsal-fin origin	31.7	103	27.6	37.7	31.9
Dorsal-fin height	23.4	94	21.8	29.0	24.5
Pelvic-fin length males	13.5	43	13.2	16.6	14.6
Pelvic-fin length females		54	11.1	15.0	13.1
Pectoral-fin length	20.7	97	19.1	24.8	21.6
Bony head length	20.9	103	20.9	24.5	22.6
Snout length	21.5	103	18.9	26.2	22.2
Upper jaw length	34.4	102	34.1	44.2	38.6
Horizontal eye diameter	44.1	103	39.1	48.5	44.6
Least interorbital width	36.6	103	32.0	39.3	35.3