Gymnogeophagus terrapurpura, Loureiro & Zarucki & Malabarba & González-Bergonzoni, 2016

Loureiro, Marcelo, Zarucki, Matías, Malabarba, Luiz R. & González-Bergonzoni, Iván, 2016, A new species of Gymnogeophagus Miranda Ribeiro from Uruguay (Teleostei: Cichliformes), Neotropical Ichthyology (Neotrop. Ichthyol.) 14 (1), No. e 150082, pp. 1-10 : 2-7

Gymnogeophagus terrapurpura , new species

u r n:l sid:z o o b a n k.o r g:a c t: 4 0 05F9 6 C -115 E - 4A63 -B 4 6D - 7A221497CA54

( Figs. 1-2A )

Gymnogeophagus rhabdotus , non Hensel, 1870. Stawikowski, 1983 (photo).

Gymnogeophagus meridionalis , non Reis & Malabarba, 1988. Reis et al., 1992: 268 (fig. 4, same specimen figured by Stawikowski, 1983 as G. rhabdotus ).

Gymnogeophagus rhabdotus , non Reis & Malabarba, 1988. Yafe et al., 2002 (feeding ecology).

Gymnogeophagus cf. meridionalis , non Reis & Malabarba, 1988. Pereyra & García, 2008 (mitochondrial phylogeny).

Gymnogeophagus sp. Serra et al., 2014:123 (photo, distribution); 182 (diagnosed in key).

Holotype. ZVC-P 12490, 60.0 mm SL, Uruguay, Canelones Department, cañada de la Lana, close to Juanicó Town, rio Santa Lucía basin ( Río de la Plata tributary), 34°35´55”S, 56°14´19” W, Sep 2009, F. Quintans.

Paratypes. Uruguay. Canelones Department. ZVC-P 9375, 1, 67.2 mm SL, same data as holotype; ZVC-P 8777, 1, 50.7 mm SL, arroyo Vejigas, Ruta 12, rio Santa Lucía basin, Río de la Plata tributary, 34º17´24”S, 55º53´11”W, Jun 2010, I. Gonzalez & C. Rojas. Florida Department. ZVC-P 7448, 4, 37.5-71.7 mm SL (1 c&s), cañada Las Piedras, rio Santa Lucía basin (Río de la Plata tributary), 34º16´20”S, 56º20´06”W, Oct 2007, R. Arocena, G. Chalar & F. Quintans; ZVC-P 2339, 19, 34.9-72.3 (2, 62.6-66.3) mm SL, arroyo Casupá, rio Santa Lucía basin, Río de la Plata tributary 34º12´15” S, 55º37´17”W, Jun 1960, O. del Puerto. San José Department. ZVC-P 81, 7, 33.4-81.4 (1, 82.4) mm SL, Sierra de Mahoma, arroyo Mahoma chico de la Sierra, rio Santa Lucía basin, Río de la Plata tributary, 34º03´36”S, 56º56´32”W, Jun 1953, M. Siri; ZVC-P 985, 27, 29.2-86.6 (1, 88.3) mm SL, Paso del arroyo Mauricio, Río de la Plata tributary, 34º42´18”S, 56º41´49” W, Dec 1959, J. Soriano. Montevideo Department. ZCV-P 3915, 9, 33.6-46.0 (1, 41.4) mm SL, Parque Rodó lake, Río de la Plata tributary, 34º54´45”S, 56º10´01”W, Oct 1999, F. Scasso, F. Quintans, A. Yafe, & M. Loureiro; ZVC-P 5746, 2, 62.0-94.0 (1, 92.2) mm SL; MNHN 3674, 4, 67.4-89.6, arroyo Las Piedras, rio Santa Lucía basin, Río de la Plata tributary, 34º43´19”S, 56º11´32”W, Feb 2005, F. Teixeira de Mello, L. Rubio & N. Vidal. Lavalleja Department. ZVC-P 3839, 1, 62.5 mm SL, rio Santa Lucía, Arequita, Río de la Plata tributary, 34º16´52”S, 55º16´42”W, Jun 1951, unknown collector; ZVC-P 5813, 2, 72.5-81.8 (1, 81.8) mm SL, arroyo Mataojo, Ruta 81, Río de la Plata tributary, 34º30´13”S, 55º24´58”W, Nov 2004, N. Rajcok, H. Ferreira, I. Terzaghi, A. Viera, A. Sacchi & M. Loureiro; Colonia Department. ZVC-P 197, 1, 70.9 mm SL, rio Uruguay, Punta Gorda, 33º54´34”S, 58º25´05”W, Set 1958, R. Vaz- Ferreira, B. Sierra & J. Soriano. Soriano Department. ZVC-P 7021, 2, 54.8-56.7 mm SL(1, 56.7 mm SL), rio San Salvador, rio Uruguay basin, 33º50´11”S, 57º44´16”W, Nov 2005, F. Teixeira, A. D´Anatro, I. González, S. Oviedo & M. Loureiro. Paysandú Department. ZVC-P 7028, 1, 51.1 mm SL, rio Queguay chico, Ruta 4, rio Uruguay basin, 32º05´36”S, 57º20´24”W, Nov 2005, F. Teixeira, A. D´Anatro, I. González, S. Oviedo & M. Loureiro; UFRGS 7934, 8, 29.9-74.0 mm SL, MCP 48718, 2, 52.4-52.6 mm SL, cañada in ruta 4, 10 Km from ruta 26, rio Queguay chico basin, rio Uruguay basin, 32°01´57”S, 57°19´30”W, Set 2005, V. Bertaco, F. Cantera, J. Ferrer & L. Malabarba. Salto Department. ZVC-P 7018, 15, 50.9-69.4 mm SL(1, 52.2mm SL; 1 c&s), rio Arapey chico, ruta 4, rio Uruguay basin, 31º02´07”S, 56º53´50”W, Nov 2005, F. Teixeira, A. D´Anatro, I. González, S. Oviedo & M. Loureiro; ZVC-P 7024, 11, 40.5-67.1 (3, 44.6-67.1) mm SL, rio Dayman, Ruta 4, rio Uruguay basin, 31º47´15”S, 57º02´12”W, Nov 2005, F. Teixeira, A. D´Anatro, I. González, S. Oviedo & M. Loureiro. Tacuarembó Department. ZVC-P 3700, 3, 29.1-57.4 (1, 57.4) mm SL, arroyo Laureles, rio Tacuarembó basin, rio Negro basin, rio Uruguay basin, 31º15´17”S, 56º03´14”W, Feb 1954, Excursión Laboratorio de Zoología; ZVC-P 3714, 5, 34.5-68.3 mm SL (1, 63.2mm SL), arroyo Laureles, rio Tacuarembó basin, rio Negro basin, rio Uruguay basin, 31º15´17”S, 56º03´14”W, Feb 1954, Excursión Laboratorio de Zoología; ZVC-P 3722, 2, 29.8-62.2 (1, 64.5) mm SL, arroyo Jabonería, Valle Edén, rio Tacuarembó basin, rio Negro basin, rio Uruguay basin, 31º49´54”S, 56º11´45”W, Apr 1968, F. Achaval. Durazno Department. ZVC-P 4057, 3, 40.4-71.0 mm SL(2, 47.5-71.0 mm SL), arroyo Las Higueras, arroyo Carpinteria basin, rio Negro basin, rio Uruguay basin, 32º56´44”S, 56º02´20”W, Oct 1959, E. Messner. Rocha Department. ZVC-P 280, 7, 55.8-86.9 (1, 89.8) mm SL, arroyo Valizas, Ruta 10, laguna Castillos basin, Atlantic Ocean tributary, 34º21´30”S, 53º50´41”W, Mar 1959, R. Vaz-Ferreira, J. Soriano & B. Soriano; ZVC-P 6049, 29, 18.6-71.2 (2, 41.4-72.8) mm SL, laguna de Brioso, Aguas Dulces, Atlantic Ocean tributary, 34º17´41”S, 53º48´16”W, Jun 2003, Limnology Section, Facultad de Ciencias; ZVC-P 6086, 1, 64.1 mm SL, arroyo Sarandí, Barra Grande, laguna Castillos basin, Atlantic Ocean tributary 34º14´19”S, 53º58´46”W, Mar 2001, F. Scasso, N. Marchand & A. D`Anatro; ZVC-P 7060, 2, 54.8-64.5 (1, 64.5) mm SL (1 c&s), cañada Sierras de Rocha, laguna de Rocha basin, Atlantic Ocean tributary, 34º21´56”S, 54º24´34”W, Feb 2001, F. Scasso, M. Loureiro, F. Quintans & J. Sawchik.

Diagnosis. The number of E1 scales, (23-25 vs. 26-30), and the substrate-brooding behavior distinguishes the new species from all other Gymnogeophagus species except for G. rhabdotus , G. meridionalis , G. setequedas , and G. che . It can be differentiated from those four species by the unique pigmentation of the dorsal fin, which consists of diagonal bright blue stripes (light brown in preserved specimens) over a red background (brown in preserved specimens) in the spiny section, and a combination of round, elliptical, and elongated bright blue spots (light brown in preserved specimens) in the soft section, vs. whitish light blue round spots (white to light brown in preserved specimens) over a red background (brown in preserved specimens) in the whole fin in G. meridionalis , or diagonal whitish light blue stripes (white to light brown in preserved specimens) over a red background in the whole spiny section of the fin and the distal ¾ of the soft section in G. rhabdotus , G. setequedas , and G. che ( Fig. 3 ). Gymnogeophagus terrapurpura can be further distinguished from G. rhabdotus by the termination of the bright blue band that runs above the upper lateral line before reaching a bright blue spot placed above the first perforated scale vs. band continuous with that spot. It can be further distinguished from G. meridionalis , G. setequedas , and G. che by the anal fin pigmentation pattern which consists of light blue rounded spots (light brown in preserved specimens) over a red to orange background (brown in preserved specimens) vs. white irregularly shaped spots over a dark red back ground in G. meridionalis ( Fig. 4 ) or diagonal light stripes in G. setequedas and G. che (Reis et al., 1992; Casciotta et al., 2000). It is also distinguished from G. meridionalis by the absence of small clear spots between anal fin rays that reach the distal edge of the fin vs. presence of these spots ( Fig. 2 ).

Description. Meristic and morphometric data summarized in Table 1 and Table 2. Body compressed, moderately elongated. Predorsal contour slightly convex; body contour at dorsal-fin base convex, decreasing in depth to caudal peduncle. Caudal peduncle rectangular, deeper than long, 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.

Snout pointed, nearly straight dorsally and ventrally in lateral aspect; short and anteriorly rounded in dorsal aspect. Eye small, close to dorsal profile of head; eye near middle of head length. Interorbital area convex, more strongly so in larger specimens; interorbital width larger than eye diameter. Posterior tip of maxilla not reaching vertical through anterior margin of eye. Mouth terminal, jaws isognathous.

Body scales ctenoid except for small cycloid scales mixed with ctenoid scales in preventral area. Small ctenoid scales on opercle; scales on preopercle small and cycloid. Caudal fin with small scales in single row between rays, from 5 to 7 series at level of lower lateral line and covering proximal third of fin on dorsal and ventral borders of fin. Other unpaired fins without scales.

Dorsal-fin origin anterior to vertical line through posterior bony margin of opercle, posterior end of depressed fin reaching caudal-fin base. Pectoral-fin edge at anal-fin origin. Anal-fin edge at caudal-fin base. Caudal fin truncate or slightly concave.

Vertebrae, 26 (13 abdominal, 13 caudal). Pectoral radials, 4. Gill rakers on first branchial arch, 12-13. Numerous canine-like teeth on upper pharyngeal jaws ( Fig. 5A ), 10- 11 slender on second pharyngobranchial, up to 40 more robust and larger on third pharyngobranchial, numerous and smaller on fourth. Second pharyngobranchial slender; third pharyngobranchial (the largest) fan-shaped; fourth pharyngobranchial triangular. Numerous teeth on lower pharyngeal jaws (fifth ceratobranchials); slender, conical, and pointed on edge, robust and rounded at center ( Fig. 5B ). Fifth ceratobranchial triangular, with robust lateral and anterior processes.

G.terrapurpura (n = 36) G. meridionalis (n = 37) G. rhabdotus (n = 33) Holotype Mean Min Max Mean Min Max Mean Min Max Standard length (mm) 60.0 63.3 37.5 92.2 57.4 41.5 83.5 57.9 25.8 99.8 Body depth 49.7 41.4 21.9 56.7 41.7 37.5 47.4 42.3 40.1 44.9 Head length 37.2 31.7 29.0 37.2 30.9 27.9 35.4 32.3 29.7 35.8 Dorsal-fin base 60.7 57.2 52.2 60.7 58.1 53.6 62.7 56.2 52.5 62.5 Anal-fin base 23.3 21.5 18.4 24.3 22.5 19.8 26.1 21.5 18.1 25.3 Predorsal length 42.9 38.9 29.7 43.0 39.3 32.1 44.5 40.2 34.5 44.6 Preanal length 68.6 67.8 62.0 72.3 66.6 59.2 70.5 67.7 53.6 75.2 Prepelvic length 41.3 41.5 33.0 45.1 41.0 36.1 44.9 42.2 39.0 46.5 Pectoral-fin length 35.9 36.4 33.2 39.6 41.4 35.8 44.9 37.0 20.2 42.0 Pelvic-fin length 33.1 31.5 25.4 40.5 35.4 28.9 46.8 31.4 13.5 52.1 Caudal-fin length 34.5 30.8 27.1 36.4 35.0 26.2 42.5 31.0 14.8 36.2 Dorsal spine 1 length 12.9 15.5 11.6 19.7 18.6 16.4 22.0 14.2 10.5 19.2 Caudal peduncle length 11.5 13.2 10.8 16.3 13.8 10.2 15.9 14.5 12.8 17.2 Caudal peduncle depth 17.5 15.7 13.1 18.2 15.4 13.4 17.2 15.2 13.2 17.3 Head depth* 112.0 113.0 96.3 128.1 116.2 101.5 127.7 116.1 99.0 132.1 Head width* 51.6 59.5 51.6 67.6 60.4 54.2 64.5 58.0 50.1 66.1 Eye diameter* 24.0 31.3 24.0 43.0 36.0 30.9 42.2 31.0 26.0 38.6 Interorbital width* 31.5 37.0 28.7 46.5 39.1 34.4 47.1 36.9 31.4 42.5 Post-orbital length* 27.2 30.1 24.6 46.7 30.8 22.5 37.0 29.2 23.7 43.1 Pre-orbital length* 42.7 40.6 28.1 48.6 37.5 27.9 51.2 39.8 26.5 50.1 Snout length* 24.1 23.0 17.2 29.2 22.9 16.2 27.5 19.2 12.1 33.3 Upper jaw length* 25.1 25.6 19.1 34.7 24.8 18.3 32.0 24.5 17.9 33.8

Color in life. Background color of dorsal region of body and head in adults light brown to olivaceous with up to seven diffuse and darker bars; first bar traversing eye from nape to ventral edge of preopercle. Black vertically elongated mid-lateral spot at third or fourth vertical band, surrounded by bright, yellow area in some specimens. Six to eight horizontal bright blue bands from behind pectoral-fin base to caudal-fin base; uppermost band interrupted in humeral region. Scales between bands red. Ventral portion of body and head light yellow to white; isthmus and branchiostegal region black in adult males and females during reproductive season. Numerous small bright blue, rounded or elongated dots usually present on cheeks, forming interrupted nearly straight line from upper portion of opercle-preopercle contact area behind eye to posterior tip of maxilla; usually one or two dots or elongated dots present anteroventral to eye. Dorsalfin background red with diagonal bright blue stripes in spiny portion; roundish, elliptic, and elongated spots in soft portion; dorsal fin border black in reproductive adults. Anal-fin background yellow to ochre in proximal and anterior portion, red distally; fin with small, bright blue, circular spots sometimes absent on distal half. Caudal-fin background red in adults, entirely covered with numerous circular to elongated hyaline spots, arranged in horizontal series between rays. Pectoral fin hyaline; pelvic fin olivaceous green to light brown, with light blue stripes between rays.

Color in alcohol. Background color brown. Red and yellow pigmentation of live specimens becomes brown or gray and light blue fin pigmentation turns hyaline to light brown. Dark spots turn darker and lateral parallel light blue bands turn brown, darker than background.

Sexual dimorphism. There is no evident sexual dimorphism except from slight differences in size. In the breeding season males are usually larger than females (10%-50% larger).

Geographic distribution. Gymnogeophagus terrapurpura is distributed from the rio Arapey (in the middle rio Uruguay basin) to all tributaries of the lower rio Uruguay basin and in the eastern coastal drainages of the Río de la Plata estuary and Atlantic Ocean in Uruguay ( Fig. 6 ).

Ecological notes. Gymnogeophagus terrapurpura has been found in a large variety of habitats including shallow lakes, floodplain lakes, rivers, and streams, mainly associated with cobble, sandy or muddy substrates. Gymnogeophagus terrapurpura is an omnivore, feeding on zooplankton, macroinvertebrates, and periphyton (to a lesser extent), reducing greatly its feeding activity during autumn and winter when water temperature decreases, as described in a low-impacted lowland stream in Florida Department by González-Bergonzoni et al. (2016, named therein as “ Gymnogeophagus sp. ”) and in a eutrophic shallow lake of Montevideo by Yafe et al. (2002, named therein as G. rhabdotus ). Gymnogeophagus terrapurpura has been observed to brood on the substrate and exhibits substantial parental care, including aggressive territorial behavior in both males and females during the reproductive season, from November to January.

Etymology. The specific epithet refers to the G. E. Hudson novel “La Tierra Purpúrea” (as it is known in the Spanish translation), in which the main character makes a trip through the same region where the new species occurs. A noun in apposition.

Conservation status. Gymnogeophagus terrapurpura is relatively frequent and abundant in the rio Negro, the middle and lower rio Uruguay basin, and in the oriental coastal drainages of Río de la Plata estuary and Atlantic Ocean in Uruguay. No specific threats were detected, and the species can be categorized as Least Concern (LC) according to IUCN criteria (International Union for Conservation of Nature (IUCN), 2011).

Figures

Fig. 1. Gymnogeophagus terrapurpura, new species, ZVC-P 12490, 60.0 mm SL, holotype, cañada de La Lana, rio Santa Lucía basin, Canelones Department, Uruguay.

Fig. 2. Non-type live specimens of (A) Gymnogeophagus terrapurpura from rio Santa Lucía basin, Canelones Department, Uruguay, (B) G. rhabdotus and (C) G. meridionalis. (B) and (C) both from rio Negro basin, Tacuarembó Department, Uruguay.

Fig. 3. Soft dorsal fin pigmentation patterns: (A-F) Gymnogeophagus terrapurpura, (G-I) G. rhabdotus, (J-K) G. meridionalis.

Fig. 4.Anal fin pigmentation patterns: (A-C) Gymnogeophagus terrapurpura, (D-E) G. rhabdotus, (F) G. meridionalis.

Fig. 5. Pharyngeal jaws of a 54.8 mm SL Gymnogeophagus terrapurpura paratype (ZVC-P 7060); (A) Ventral view of left upper pharyngeal jaws; (B) Dorsal view of lower pharyngeal jaws; p2-4 = pharyngobranchials 2-4. Scale bar = 1 mm.

Fig. 6. Distribution of Gymnogeophagus terrapurpura. Yellow dot indicates type locality. Map modified from Shuttle Radar Topography Mission (SRTM), Courtesy NASA/JPL-Caltech.