Hyphessobrycon vinaceus, Bertaco & Malabarba & Dergam, 2007

Bertaco, Vinicius A., Malabarba, Luiz R. & Dergam, Jorge A., 2007, New Hyphessobrycon from the upper rio Pardo drainage in eastern Brazil (Teleostei: Characiformes: Characidae), Neotropical Ichthyology 5 (3), pp. 245-249 : 246-248

Hyphessobrycon vinaceus , new species Figs. 1 and 2

Holotype. MCP 40916, 56.5 mm SL, male; Brazil, Minas Gerais, São João do Paraíso, rio São João, tributary of the upper rio Pardo , 15 o 09’50"S 42 o 09’45"W, 26 Apr 2006, J. A. Dergam & A.A. Oliveira.

Paratypes. MCP 40141, 6 (2 males, 46.7-54.1 mm SL; 1 male c& s 46.7 mm SL; 4 females, 56.1-62.8 mm SL; 1 female c& s 49.6 mm SL) , MZUSP 94439 , 3 (1 male, 56.3 mm SL; 2 females, 48.3-56.9 mm SL), collected with the holotype ; MCP 40915 (3 males, 51.0- 54.0 mm SL), same data of the holotype; these specimens were kept in aquarium for one year .

Diagnosis. Hyphessobrycon vinaceus is distinguished from all other species of Hyphessobrycon except of H. melanostichos Carvalho & Bertaco , H. notidanos Carvalho & Bertaco , and the species of the ‘rosy tetra clade’ Weitzman & Palmer (1997), by the red or reddish pigmented body in live specimens. Hyphessobrycon vinaceus differs from the species included in the ‘rosy tetra clade’ in the number of teeth in the inner row of the premaxilla (4 or 5 vs 7 to 12), and in the number of branched anal-fin rays (15-17 vs 22-29); it differs from H. melanostichos by the absence of a conspicuous longitudinal broad black band beginning on the posterior margin of orbit and reaching the tip of middle caudal fin rays; from H. notidanos by the lack of an elongated dorsal fin in mature males, in the number of dorsal-fin rays (ii,9 vs iii,8), and number of perforated lateral-line scales (10-26 vs 6-9).

Description. Morphometric data summarized in Table 1. Body compressed and moderately deep; greatest body depth anterior to dorsal-fin origin. Dorsal head profile straight or slightly convex. Dorsal body profile convex from supraoccipital tip to base of last dorsal-fin ray, and straight from that point to adipose-fin origin. Ventral profile of head convex. Ventral profile of body convex from pectoral-fin origin to anal-fin origin. Body profile along anal-fin base straight and posterodorsally slanted. Caudal peduncle elongate, nearly straight to slightly concave along both dorsal and ventral margins.

Snout rounded from margin of upper lip to vertical through anterior nostrils. Mouth terminal. Maxilla extending posteriorly to under middle of orbit, slightly curved, and aligned at approximately 45 degrees angle relative to longitudinal axis of body. Anterodorsal border of maxilla concave, posterodorsal border slightly convex, anteroventral border concave, and posteroventral border convex. Maxilla slightly widened posteriorly.

Premaxilla with two tooth rows; outer row with 2-4, tricuspid or pentacuspid teeth with central cusp longer; inner row 5 (one with 4) teeth with 5-7 cusps and central cusp longer and broader than other cusps, inner row teeth gradually decreasing in length from first to fourth teeth, last tooth considerably smaller. Two to three maxillary teeth, with 5 cusps, central cusp slightly longer. Four or 5 anteriormost dentary teeth larger, with 5-7 cusps, followed by medium sized tooth with 5 cusps, and 5-6 smaller teeth with 1-3 cusps or conical; central cusp in all teeth two to three times longer and broader than remaining cusps. Cusp tips slightly curved posteriorly and lingually ( Fig. 2).

Scales cycloid, moderately large. Lateral line incomplete, perforated scales 10-26 (26, mean = 16, n = 12). Longitudinal scale series including lateral-line scales 32-34 (34, mean = 33.1, n = 12). Scale rows between dorsal-fin origin and lateral line 5 (5, one with 4, mean = 4.9, n = 12); scale rows between lateral line and pelvic-fin origin 3-4 (4, mean = 3.6, n = 12). Predorsal scales 11-12, arranged in regular series (11, mean = 11.7, n = 12). Scales rows around caudal peduncle 14 (n = 12). Scale sheath along anal-fin base with 3-5 scales in single series (5, n = 12), extending posteriorly to base of first rays.

Dorsal-fin rays ii,9 (n = 13); first unbranched ray approximately one-half length of second ray. Males with small bony hooks in distal one-third of first to fifth branched rays. Dorsal-fin origin located approximately at middle of SL and posterior to vertical through pelvic-fin origin. Adipose-fin located approximately at vertical through insertion of 13 th - 15 th branched anal-fin rays. Anal-fin rays iii-iv,15-17 (iii,16, mean = 16.1, n = 13). First unbranched ray usually only apparent in cleared and stained specimens. Anal-fin profile smoothly concave in females and nearly straight in males. Anal-fin origin located posterior to vertical through base of last dorsal-fin ray. Anal-fin rays of males bearing one pair of retrorse bony hooks along posterolateral border of each segment of lepidotrichia, usually along last unbranched ray and fifteen anterior branched rays; hooks more numerous along first through tenth branched rays. Hooks usually located along posteriormost branch and distal 1/2 to 2/3 length of each ray. Pectoral-fin rays i,9-12 (i,9, mean = 11.3, n = 13). Males with small bony hooks on distal portion of first to fifth branched rays. Pelvic-fin rays i,7 (one with i,6,i, n = 13). Pelvicfin origin located anterior to vertical through dorsal-fin origin. Pelvic fin of males usually bearing small bony hooks along ventromedial border of second to third branched rays. Caudalfin forked, with 19 principal rays with small bony hooks at tip of middle caudal-fin rays. Dorsal procurrent rays 10, and ventral procurrent rays 9 (n = 2).

Precaudal vertebrae 16; caudal vertebrae 16-17; total vertebrae 32-33. Supraneurals 5. Gill-rakers 6/10 (n = 2).

Color in alcohol. Dorsal and dorsolateral portions of head and body dark brown. Infraorbital and opercular areas covered with scattered, dark chromatophores. Scales on lateral and ventral surface of body bordered with dark brown chromatophores forming a reticulate color pattern. Dark anterior humeral spot vertically-elongate, and narrowing ventrally, located over second to fourth lateral-line scales and extending over 4-5 horizontal series of scales including lateral line. Second humeral spot diffuse, located nearly above 7 th- 8 th lateral line scale and at anterior end of midlateral stripe, and extending usually over two horizontal series of scales above lateral line. Faint midlateral body stripe extending from second humeral spot to tip of median caudal-fin rays, gradually wider and more intensely pigmented towards caudal peduncle. Midlateral body stripe slightly wider on caudal peduncle and caudal-fin base forming small spot. Fins with scattered dark chromatophores ( Fig. 1). Some specimens examined soon after fixation in formalin with ventrolateral portion of body, and caudal fin base with intensely red-orange or reddish coloration.Males and females with similar color pattern.

Color in life. Color pattern similar to that described for alcohol preserved specimens except as follows. Body dorsal portion green to gray brown. Abdomen and opercle portions silvery to brilliant green. Body portion above anal-fin base, and pectoral, pelvic, and anal fins intensely red or reddish pigmented. Dorsal and caudal fins green or yellowish brown. Red or reddish coloration is more evident in freshly preserved specimens in formalin.

Sexual dimorphism. Males of H. vinaceus are easily recognized by the presence of bony hooks on all fin rays, observed in males larger than 46.7 mm SL. Males and females also slightly differ in anal-fin shape, which is concave in females and nearly straight in males. One male and female (46.7 and 49.6 mm SL) were dissected before clearing and staining, and only the male had mature gonads. Gill glands were not found on first gill arch in both males and females.

Distribution. Hyphessobrycon vinaceus is known only from rio São João, in the headwaters of the rio Pardo drainage, a coastal drainage in eastern Brazil.

Etymology. The specific name vinaceus is from Latin and means reddish, and it is in allusion to the body coloration red or reddish observed in live specimens.

Ecological notes. At the type locality, the rio São João is a fast running clear water and shallow river about four to five meters wide, with sandy bottom, and large amount of riparian vegetation. Live specimens of H. vinaceus were caught in rapid stretches just below a small waterfall. Hyphessobrycon vinaceus was collected syntopically with Aspidoras cf. albater and Otothyropsis sp.