Gymnogeophagus lipokarenos, Malabarba & Malabarba & Reis, 2015

Malabarba, Luiz R., Malabarba, Maria Claudia & Reis, Roberto E., 2015, Descriptions of five new species of the Neotropical cichlid genus Gymnogeophagus Miranda Ribeiro, 1918 (Teleostei: Cichliformes) from the rio Uruguay drainage, Neotropical Ichthyology (Neotrop. Ichthyol.) 13 (4), pp. 637-662 : 653-656

Gymnogeophagus lipokarenos , new species urn:lsid:zoobank.org:act:205B6DAA-6A95-4D7D-A29A-A064512F110E

Figs. 6e , 11 , 12

Gymnogeophagus sp. E . - Wimberger et al., 1998 (molecular phylogeny).

Holotype. MCP 23522 , male, 108.5 mm SL, rio Dourados at Linha Várzea , on road from Severiano de Almeida to Aratiba, Rio Grande do Sul, Brazil, approx. 27°23’S 52°13’W, 12 Dec 1992, P. H. Wimberger, R. E. Reis & C. S. Fontana.

Paratypes. Brazil: Rio Grande do Sul: MCP 16127 (8, 68.2- 119.8 mm SL) , UMMZ 225381 (8, 71-85 mm SL), collected with the holotype . MCP 12958 (34 alc, 3 c&s, 48.7-124.4 mm SL) , ZVCP 12957 (2, 88.9-99.8 mm SL), rio Dourados between Três Barras and Mariano Moro , Mariano Moro , approx. 27°20’S 52°14’W, 9 Dec 1988, R. E. Reis, P. Azevedo, A. C. Bergmann, E. H. Pereira & A. Ramires . Santa Catarina: MCP 12996 (14, 55.3-104.1 mm SL), rio Jacutinga on road BR-283 from Seara to Concórdia, Concórdia , 27°11’15”S 52°10’03”W, 8-10 Dec 1988, R. E. Reis, A. C. Bergmann, E. H. Pereira, P. V. Azevedo & A. Ramires . MCP 16117 (10, 46.7-74.8 mm SL), and UMMZ 225499 (5, 58-70 mm SL), same locality as MCP 12996, 12 Dec 1992, P. H. Wimberger, R. E. Reis & C. S. Fontana . UFRGS 15743 (3, 107.5- 127.5 mm SL), arroio Lajeado Romana, Três Passos , 27°27’24.5”S 53°50’46.5”W, 25 Oct 2011, J. Anza . UFRGS 15752 (3, 88-114.34 mm SL), arroio do Tigre, tributary to the rio Turvo, Três Passos , 27°26’43.7”S 53°49’02.4”W, 29 Oct 2011, J. Anza . UFRGS 7551 (2, 59.9-77.6 mm SL), rio Jacutinga, linha Canavesi, near to CASAN station of water capture, Concórdia , 27°14’03”S 52°01’40”W, 15 Jan 2005, J. Scalcon . UFRGS 7552 (1, 106.6 mm SL), same locality as UFRGS 7551, 30 Oct 2004, J. Scalcon . UFRGS 7553 (1, 125 mm SL), rio Jacutinga, Linha Unidos, on lower portion of Itá reservoir, Arabutã , 27°09’37”S 52°08’30”W, 30 Oct 2004, J. Scalcon .

Additional non-type specimens. Rio Grande do Sul: MCP 11123 (13), sanga Águas Frias , ca. 100 m from its mouth into rio Uruguay, Iraí, approx. 27°12’S 53°16’W, 22 Dec 1985 . MCP 12252 (4), rio Uruguay on road BR-153, Marcelino Ramos , approx. 27°22’S 52°01’W, 17 Oct 1988 . MCP 12299 (11), flooded area of rio Dourados at Mariano Moura, 17 Aug 1988 . MCP 18556 (2), rio Dourados between Três Barras and Mariano Moro, Mariano Moro, approx. 27°22’S 52°14’W, 21 Sep 1995 . MCP 18982 (10), same locality as MCP 18556, 16 Jan 1996 . MCP 19059 (2), same locality as MCP 18556, 17 Apr 1996 . MCP 18575 (1), rio Uruguay between confluences with rio Passo Fundo and rio Chapecó, Erval Grande, approx. 27°13’S 52°49’W, 22 Sep 1995 . MCP 18978 (3), same locality as MCP 18575, 17 Jan 1996 . MCP 40083 (2 alc.), rio Passo Fundo , Barra do Guarita, 27°11’47”S 53°39’07”W, 26 Jan 2006 . MCP 40250 (5 alc.), rio Passo Fundo , Nonoai, 27°43’16”S 52°29’01”W, 06 Apr 2006 . UFRGS 10303 (10), Monjolinho Hydroeletric reservoir, Nonoai, 27°20’46”S 52°43’54”W, 11 Jul 2011 . UFRGS 15740 (7), rio Turvo , Três Passos, 27°27’15”S 53°50’29”W, 29 Oct 2011 . Santa Catarina: MCP 12118 (8), rio Uruguay at Alto Feliz , 6 km from Terra Vermelha, Itá, approx. 27°14’”S 52°15’W, 25 May 1988 . MCP 12150 (5), rio Jacutinga at road BR-283, Concórdia, aprox. 27°09’S 52°09’W, 25 Jun 1988 , E. Lerner. MCP 12253 (11), rio Uruguay at Itá , approx. 27°17’S 52°19’W, 16 Aug 1988 . MCP 12312 (39), same locality as MCP 12253, 16 Oct 1988 . MCP 12512 (3), same locality as MCP 12253, 1-2 Oct 1988 . MCP 12923 (5), same locality as MCP 12253, 7-8 Dec 1988 . MCP 13345 (4), same locality as MCP 12253, 15-16 Feb 1989 . MCP 18977 (1), same locality as MCP 12253, 12 Jan 1996 . MCP 12518 (17), rio Jacutinga on road BR-283 from Seara to Concórdia, Concórdia, approx. 27°09’S 52°09’W, 2 Feb 1988 . MCP 13342 (18), same locality as MCP 12518, 16 Feb 1989 . MCP 18979 (1), same locality as MCP 12518, 14 Jan 1996 . MCP 18980 (2), rio do Engano (or rio Uvá), on road between Itá and Seara, approx. 27°08’S 52°13’W, 13 Jan 1996 . MCP 18981 (2), rio Rancho Grande on road between Piritiba and highway BR-153, Concórdia, approx. 27°21’S 51°57’W, 11 Jan 1996 . MCP 20399 (3 alc.), rio Uruguay, Mondaí , 27°06’30”S 53°28’33”W, 02 May 1997 . MCP 20812 (2 alc.), rio Macaco Branco on road Iporã do Oeste to Tunápolis, Tunápolis, 26°58’39”S 53°37’24”W, 28 Jan 1998 . MCP 20869 (3 alc.), arroio da Taipa 13 km from Mondaí , Mondaí, 27°07’46”S 53°28’22”W, 27 Jan 1998 . MCP 20873 (6 alc.), rio Jundiá on road São Pedro to Tunápolis, Itapiranga, 27°01’17”S 53°38’58”W, 27 Jan 1998 . MCP 20919 (13 alc.), rio Iracema and Tributary, Riqueza, 27°08’S 53°20’W, 26 Jan 1998 . UFRGS 10900 (2), rio Barra Grande tributary of rio Uruguay, about 7 km from Palmitos, Palmitos, 27°05’28”S 53°04’32”W, 11 Jul 2008 . UFRGS 10918 (2), rio Dourados on Vila Dourados near locality of Santa Cruz, Itapiranga, 27°08’20”S 53°39’54”W, 12 Dec 2007 . UFRGS 10923 (2), rio Macaco Branco on locality Santo Antônio, Itapiranga, 27°05’25”S 53°44’13”W, 13 Dec 2007 .

Diagnosis. Gymnogeophagus lipokarenos is diagnosed from all congeners by the bright yellow color pattern of the unpaired fins (vs. mostly red in other species), covered with white dots aligned between rays; distal border of dorsal fin and dorsal and ventral contours of caudal fin red with thin light stripes. The adipose hump in mature males is prominent, extending dorsally above the tip of the longest dorsal-fin spines (vs. less developed).

Description. Morphometric data summarized in Table 5. Body elongate, laterally compressed. Dorsal profile of head convex between mouth and interorbital area in young, slightly convex in adults; slightly convex from interorbital region to dorsal-fin origin. Predorsal body profile modified in adult males which may have very large adipose hump between nostrils and dorsal-fin origin. Adipose hump sometimes surrounding origin of dorsal fin in large males ( Fig. 11 ). Dorsal-fin base convex. Caudal peduncle longer than deep, with dorsal and ventral profile slightly concave.

Snout slightly blunt and rounded dorsally in young; slightly rounded dorsally and slightly rounded to nearly straight ventrally in adults; narrow and anteriorly rounded in dorsal aspect. Eye small, close to dorsal profile of head in juveniles and progressively farther in larger specimens (about one half eye diameter in specimens larger than 70 mm SL); eye slightly posterior or near middle of head length. Interorbital area convex, more strongly so in larger specimens; interorbital width smaller than one eye diameter in young (up to 50 mm SL) and progressively larger than one eye diameter in larger specimens. Posterior tip of maxilla not reaching vertical line across anterior margin of eye. Upper jaw equal or slightly longer than lower jaw.

Body scales large and ctenoid, smaller around pectoral fins; scales cycloid in preventral area. Caudal fin with single series of small ctenoid and elongated scales between contiguous rays reaching proximal third of fin in both upper and lower lobes. Soft portion of dorsal fin of males without scales between contiguous rays. Cheek scales cycloid in 4 or 5 rows; cheek naked anteroventrally. Opercle mostly scaled, especially dorsally. Subopercular scales ctenoid in one or two irregular rows. Upper lateral line 14(1), 17*(6), 18(5), 19(1); lower lateral line 8(1), 9*(4), 10(4), 11(4), with 1 to 3 small perforated scales continuing onto caudal-fin base. Scales between upper lateral line and dorsal fin 4*(9), 5(12). Scales between upper lateral line and anal fin 8*(6), 9(7). E1 scales 25(1), 26*(8), 27(4).

Dorsal-fin spines 13*(2), 14(11); dorsal-fin soft rays 9(5), 10(5), 11*(3). First dorsal-fin spine inserted slightly anterior to vertical line across posterior bony margin of opercle. Soft dorsal fin in young rounded, slightly pointed in adult females, reaching to or almost reaching caudal-fin base. Soft dorsal fin in mature males pointed, with 3rd or 4th ray longest, reaching proximal third to distal half of caudal fin. Anal-fin with 3 spines (one specimen with 4) and 7(1), 11(8), 9*(1) soft rays. Anal-fin origin under last dorsal-fin spine or first soft ray; soft portion nearly rounded in young and females and clearly pointed in males. Pectoral fin with rounded tip in young and slightly pointed in adults; 3rd ray longest, reaching to or slightly passing vertical crossing anal-fin origin. Pelvic fin pointed, more conspicuously so in adult males; 2nd soft ray longest reaching area of anal opening in females and passing anal-fin origin in mature males. Caudal-fin margin concave.

Jaw teeth small, conical, with slightly recurved tips. Upper jaw with outer regular row of 14-25 teeth in each premaxilla (number increasing with specimen size) distinct from irregular tooth band of slightly smaller teeth. Lower jaw with narrow tooth band arranged in 3-4 irregular rows; all teeth with approximately same size. Outer hemiseries with 18-22 teeth. Lower limb of first gill arch with 6-9 gill rakers; upper limb lobed with 5-7 gill rakers on its margin. Number of gill rakers increasing with age.

Lower pharyngeal tooth plate slightly wider than long; length of bone 92% of width; teeth covering occlusion surface; 19-20 teeth in posterior row, 17 on median row. Lateral marginal teeth smaller on caudal half of plate; posteromedial teeth much larger, cylindrical with medial, blunt cusps of molariform aspect ( Fig. 6e ).

Vertebrae 13+ 15 in three cleared and stained specimens.

Color in alcohol. Mature males ( Figs. 11a , 12a ): ground color of body light brown laterodorsally and light brown lateroventrally. Nine to 14 dark double vertical bars hardly discernible along midlateral surface of body, distributed between pectoral-fin base and vertical through last anal fin ray origin, not seen in caudal peduncle. Number of vertical bars increase from small to large specimens. Midlateral spot present but without defined borders, on scales 8-10 or 9-11 of upper lateral line and of two scale rows below upper lateral line. Dark band in front of dorsal-fin origin, extending ventrally and slightly posteriorly. Head light brown, with difuse dark markings ventral and posterior to eye and in upper portion of opercle. Snout and adipose hump dusky. Dark band covering cheek absent. Isthmus and branchiostegal membrane light brown. Pectoral fin hyaline. Pelvic fin dark brown. Dorsal fin faint brown with small, narrow white stripes on spiny portion and circular white spots on soft portion. Anal and caudal fins faint brown covered with circular white dots. Color in alcohol of preserved females ( Fig. 12b ) and juveniles not clearly distinct from that described for males. Most differences related to isthmus and branchiostegal membrane light brown, instead of dark brown as observed in males, and presence of conspicuous vertical dark band covering cheek, below eye.

Color in life. Vertical bars not visible in freshly collected mature males ( Fig. 11b ). Ground color of dorsal region of body in males bluish green with longitudinal series of bright spots along scale rows. Middorsal region including adipose hump dark blue. Head largely greenish blue with few red markings on cleithrum. Light blue spots below and posterior to eye, opercle and on body surface above pectoral fin. Lateroventral color bluish white with parts of vertical bars barely discernible. Dorsal fin red with white stripes in spinous portion, and along dorsal border; soft portion yellow covered with round white spots. Caudal fin yellow covered with white spots; dorsal and ventral borders red with white stripes. Most of anal fin yellow covered with white spots; distal region with white stripes. Pectoral fin hyaline; pelvic fin dark.

Distribution. Gymnogeophagus lipokarenos is found in the upper portion of the rio Uruguay drainage and its main tributaries ( Fig. 1 ).

Etymology. From the Greek lipos, meaning fat, and from the Greek kara, meaning head, in allusion to the extremely large adipose hump of adult males ( Fig. 11 ). A noun in apposition.

Conservation status. Gymnogeophagus lipokarenos is frequent and abundant in the upper rio Uruguay. Despite its Extent of Occurrence (EOO) is approximately 7,600 square kilometers, no specific threats were detected, and the species can be categorized as Least Concern (LC) according to IUCN criteria ( IUCN, 2014).

Figures

Fig. 6. Lower pharyngeal tooth plates in occlusal view: a, G. pseudolabiatus, MCP 11228, 71.6 mm SL; b, G. mekinos, MCP 11251, 84.2 mm SL; c, G. constellatus, MCP 10827, 91.4 mm SL; d, G. missioneiro, MCP 12725, 59.3 mm SL; e, G. lipokarenos, MCP 12991, 89 mm SL. Scale bars = 1 mm.

Fig. 11. Gymnogeophagus lipokarenos: top, holotype, male, MCP 23522, 108.5 mm SL, rio Dourados at Linha Várzea, on the road from Severiano de Almeida to Aratiba, Rio Grande do Sul, Brazil; bottom, holotype, photo taken just after capture.

Fig. 12. Gymnogeophagus lipokarenos: top, paratype, male, UFRGS 15752, 115 mm SL, arroio do Tigre, tributary of the rio Turvo, Três Passos, Rio Grande do Sul, Brazil; bottom, paratype, female, UFRGS 15743, 107 mm SL, arroio Lajeado Romana, Três Passos, Rio Grande do Sul, Brazil.

Fig. 1. Rio Uruguay and adjacent drainages showing the distribution of the examined specimens of Gymnogeophagus lipokarenos (dark blue), G. missioneiro (light blue), G. constellatus (red), G. pseudolabiatus (orange), and G. mekinos (yellow). Stars represent the type localities.