Gymnogeophagus tiraparae, González-Bergonzoni & Loureiro & Oviedo, 2009

González-Bergonzoni, Iván, Loureiro, Marcelo & Oviedo, Sebastián, 2009, A new species of Gymnogeophagus from the río Negro and río Tacuarí basins, Uruguay (Teleostei: Perciformes), Neotropical Ichthyology 7 (1), pp. 19-24 : 20-21

Gymnogeophagus tiraparae , new species Figs. 1-2

Holotype. ZVC-P 7870, 99.7 mm SL, male, Uruguay, Tacuarembó, Pueblo Ansina, río Tacuarembó at Road 26, tributary of río Negro (lower río Uruguay drainage), 31º53’01’’S, 55º28’38’’W, Nov 2005, M. Loureiro, F. Teixeira de Mello , S. Oviedo, A. D’Anatro & I. González.

Paratypes. All from Uruguay. Lower río Uruguay drainage: ZVC-P 2690, 2, 45.2-52.2 mm SL, Durazno, Arroyo Cordobés , Estancia Las Pitangas , Cercanías de Paso del Gordo , 32º33’31’’S, 55º17’38’’W, Jan 1963, Dolber; ZVC-P 3703, 2, 69.3-80.7 mm SL, Durazno, río Negro, Paraje 329, Road 6, 32º26’44’’S, 55º26’03’’W, Oct 1998, F. Achaval; ZVC-P 6684, 9, 42.9-60.3 mm SL, Durazno, río Yí , Paso San Borja, 33º23’50’’S, 56º24’10’’W, Nov 2005, M. Loureiro, F. Teixeira de Mello , S. Oviedo, A. D’Anatro & I. González.; ZVC-P 6687, 1, 57.2 mm SL, río Negro, Paraje 329, Road 6, Durazno, 32º26’44’’S, 55º26’03’’W, Nov 2005, M. Loureiro, F. Teixeira de Mello , S. Oviedo, A. D’Anatro & I. González; ZVC- P 6688, 1, 72.9 mm SL, río Yí , Paso San Borja, Durazno, 33º23’50’’S, 56º24’10’’W, Nov 2005, M. Loureiro, F. Teixeira de Mello , S. Oviedo, A. D’Anatro & I. González; ZVC-P 6689, 3, 47.1–65.9 mm SL, same data as holotype; ZVC-P 6692, 3, 58.9-79.5 mm SL, río Yí , Paso San Borja, Durazno, 33º23’50’’S, 56º24’10’’W, 2005, Pablo Laurino; ZVC-P 6694, 1, 85.9 mm SL, río Yí , Paso San Borja, Durazno, 33º23’50’’S, 56º24’10’’W, 2005, Pablo Laurino; ZVC-P 6695, 1, 91.9 mm SL, río Negro, Paraje 329, Road 6, Durazno, 32º26’44’’S, 55º26’03’’W, Aug 2005, I. González; ZVC-P 7656, 2, 44.6-76.3 mm SL, río Yí , Polanco del Yí , Florida, 33º18’45’’S, 56º09’08’’W, Mar 2008, M. Loureiro, F. Teixeira de Mello , M. Zarucki, L. Ziegler & I. González; ZVC-P 7658, 1, 62.0 mm SL, río Tacuarembó Chico, Paso de los Novillos, Tacuarembó, 32º11’09’’S, 55º27’48’’, Mar 2008, F. Teixeira de Mello , M. Masdeu, G. Goyenola, M. Goyenola, J. Clemente & I. González; ZVC-P 7938, 5, 62.3-97.1 mm SL, río Negro, embalse de represa de Baygorria, Durazno, 32º52’21’’S, 56º48’13’’W, Oct 2008, F. Teixeira de Mello & Federico Viana; MNHN 3277 , 6 , 47.6–66.6 mm SL, same data as holotype. laguna Merin drainage: ZVC-P 7869, 1, 45.7 mm SL, río Tacuarí , Road 18, Cerro Largo, 32º45’46’’S, 53º42’58’’W, 2005, Pablo Laurino. UFRGS 10203 , 3 , 52.4–64.3mm SL, río Tacuarembó y ruta 26, Pueblo Ansina, Dpto Tacuarembó, 31º53’01’’S, 55º28’38’’W, Nov 2005, M. Loureiro, A. D’anatro, F. Teixeira de Mello , S. Oviedo, I. González. UFRGS 10204 , 2 , 52.3–78.6 mm SL, río Yí , Paso San Borja , Durazno, 33º23’50’’S, 56º24’10’’W, Nov 2005, I. González

Diagnosis. The new species can be distinguished from all others Gymnogeophagus species by the presence of the following unique characters: adipose hump on head deeper than the dorsal-fin upper border, adipose hump with anterior profile vertical, extending from the upper lip to the dorsal-fin origin, absence of transversal bands on body, two horizontal series of moderately elongated light blue dots between dorsal-fin spines, and a series of light blue stripes between soft rays, sometimes merged with the second series of elongated dots, and always with a red ground color between series of dots, and caudal fin with dots vertically aligned on its distal border. Gymnogeophagus tiraparae can be further distinguished from G. gymnogenys by the E1 scale count (27-30, 96% with 28-30 vs. 26-29, 74% with 26-27 in G. gymnogenys (Malabarba & Reis, 1988)) ; from G. gymnogenys and G. caguazuensis by the absence of a black line anterior to eye (vs. present); from G. gymnogenys and G. australis by the body depth (33.6-41.4% SL vs. 23-29% SL and 41.2-43.3% SL, respectively); from G. australis by the presence six to eight parallel light green bands on body (vs. absence), by snout to dorsal-fin origin length (30.5-38.4% SL vs. 23.6-30.7% SL), and by the head depth (81-104% HL vs. 109.7-116.2% HL).

Description. Standard length of specimens examined 35.2 to 130.5 mm; meristic and morphometric data in Table 1 . Body elongated, laterally compressed. Predorsal contour convex. Reproductive males with adipose hump on top of head from dorsal-fin origin to upper lip, deeper than dorsal-fin upper border and with anterior profile vertical. Mouth terminal and jaws isognathus. Body contour at dorsal-fin base slightly arched, decreasing from anterior part to caudal peduncle. Caudal peduncle rectangular, longer than deeper, dorsal and ventral profiles slightly concave. Body contour slightly convex between lower lip and last anal-fin ray, with straight segment between pelvic and anal fins.

Body scales moderately large and ctenoid except for small cycloid and ctenoid scales in preventral area. Small ctenoid scales on opercle; scales on preopercle, when present, small and cycloid. Small ctenoid scales on base of hump (in adult reproductive males only) to approximately vertical line passing on center of eye.

Proximal third to half of caudal fin with small scales in single series between rays. Dorsal-fin without scales and its origin posterior to vertical line through posterior bony margin of opercle. Large males with sixth dorsal-fin soft ray longest, reaching proximal third of caudal fin. Pectoral fin reaching anal-fin origin. Anal fin reaching caudal-fin base. Caudal fin truncated or slightly concave; lyrate in large reproductive males; very deep distally, from distal edge of extended dorsal fin to distal edge of extended anal fin.

Color in life. Ground color of dorsal region of body in adults, brownish to light olivaceous, with one large dark spot on nape and two large dark spots on body flank, just below dorsal-fin base, first between eighth and twelfth dorsal-fin spine and second from first to sixth dorsal-fin soft ray. Well defined dark, circular, lateral spot just below upper portion of lateral line; often with three or four dark blotches on sides of body, anterior dark blotch larger and extending through lateral spot, other blotches smaller and aligned on sides, reaching caudal peduncle. Ventral portion of body yellowish in adult males and light olivaceus in adult females. Six or more lateral, parallel, bright green to pale blue bands from posterior part of pectoral-fin base to caudal-fin base. Numerous small bright blue dots usually present on cheeks, bright green colored lips usually present in reproductive males. Adipose hump, when present, with brownish ground coloration without dark line anterior to eye, suborbital stripe usually absent or diffuse in reproductive males. Dorsal fin yellowish on base and reddish between two horizontal series of elongated, hyaline to light blue dots, and third distal series in posterior part of fin, often fused with proximal series; small proximal circular dots very close to dorsal-fin base often present, from the fifth or sixth dorsal-fin soft ray, to its distal end. Caudal fin with red ground color in adults and entirely covered with numerous circular hyaline dots, arranged into horizontal series between rays. Distal dots smaller, vertically aligned. Pectoral fin hyaline, pelvic fin with light blue stripes between fin rays; anal fin yellowish in proximal portion and reddish distally between many small light blue dots spread along fin.

Color in alcohol. Ground color turns paler. Reddish and yellowish pigmentations turn light brown or gray and light blue fin pigmentation turns hyaline. Dark spots turn darker and lateral parallel light green bands turn clearer, almost invisible.

Distribution. Gymnogeophagus tiraparae is distributed in the middle rio Negro basin, including main tributaries (lower río Uruguay basin) and in río Tacuarí (laguna Mirim basin) ( Fig. 3 ).

Ecology. Localities where the new species was collected are large rivers, higher than stream order 6, with clear water, sandy or rocky bottoms, and little vegetation. Specimens were collected using cast nets, seine and electro fishing device. Females holding juveniles in their mouths were collected at the end of spring and summer.

Etymology. Gymnogeophagus tiraparae takes its name from María Luisa Tirapare, a Guaraní woman who founded the now disappeared town of San Borja del Yí (close to the first locality where the new species was found), the last native town in Uruguayan land, where natives, fugitive African slaves, gauchos, and other outsiders lived together.

Figures

Fig. 1. Gymnogeophagus tiraparae, holotype, ZVC-P 7870, 99.7 mm SL, male, río Tacuarembó on Road 26, Pueblo Ansina, tributary to the río Negro (lower río Uruguay drainage).

Fig. 2. Gymnogeophagus tiraparae, male not preserved from the río Yí, tributary to the río Negro (lower río Uruguay drainage).

Fig. 3. Distribution of Gymnogeophagus tiraparae. Star = type locality.