Rineloricaria aurata ( Knaack, 2003 )

Vera-Alcaraz, Héctor S., Pavanelli, Carla S. & Zawadzki, Cláudio H., 2012, Taxonomic revision of the Rineloricaria species (Siluriformes: Loricariidae) from the Paraguay River basin, Neotropical Ichthyology 10 (2), pp. 285-311 : 288-293

Rineloricaria aurata ( Knaack, 2003)

Figs. 3 , 4a , 5 , 6

Hemiloricaria aurata Knaack, 2003: 58 [original description; holotype: ZMA 123591; pictures of the holotype alive and conserved; type-locality: río Aquidabán at Paso Barreto, Concepción, Departamento de Concepción, Paraguay]. - Ferraris, 2007: 245 [listed; Paraguay].

Rineloricaria . - Knaack, 2003: 57 [picture of a specimen from the Aquidabán River in Paraguay; comparison with Hemiloricaria aurata ].

Hemiloricaria cacerensis non Miranda Ribeiro, 1912. - Carvalho &Albert, 2011: 195 [Guaporé River].

Diagnosis. Rineloricaria aurata is distinguished from most of its congeners by having four lateral plate series in longitudinal rows below the dorsal fin, the mid-dorsal series absent ( Fig. 4a ) [vs. five lateral plate series in longitudinal rows below the dorsal fin, the mid-dorsal series present and consisting in two to ten keeled plates situated below the dorsal series and beginning around insertion of the first dorsal-fin ray ( Fig. 4b and 4c ) in R. aequalicuspis , R. altipinnis , R. anhanguapitan , R. anitae , R. baliola , R. cacerensis , R. capitonia , R. caracasensis , R. daraha , R. eigenmanni , R. fallax , R. formosa , R. hasemani , R. heteroptera , R. isaaci , R. jaraguensis , R. jubata , R. konopickyi , R. kronei , R. latirostris , R. maacki , R. malabarbai , R. maquinensis , R. melini , R. microlepidogaster , R. morrowi , R. osvaldoi , R. pentamaculata , R. phoxocephala , R. platyura , R. reisi , R. rupestris , R. steindachneri , R. stewarti , R. teffeana , R. tropeira , and R. zaina ]; and by presenting breeding male specimens with sexually dimorphic odontodes on the dorsum of the head and predorsal region ( Fig. 3 ) [vs. sexually dimorphic odontodes absent on dorsum of the head and predorsal region ( Fig. 12 ) in R. cadeae , R. castroi , R. catamarcensis , R. langei , R. lima , R. longicauda , R. misionera , R. nigricauda , R. pareiacantha , R. parva , R. quadrensis , R. sanga , R. setepovos , R. stellata , R. strigilata , R. uracantha , and R. wolfei ]. It is distinguished from remaining members of the genus by having the dorsum of the head rough, with pronounced ridges from nasal plates to the frontal bones [vs. dorsum of the head smooth, without ridges between nostrils and interorbital region in R. beni , R. felipponei , R. lanceolata , R. magdalenae , R. sneiderni , and R. thrissoceps ].

Description. Morphometric data presented in Table 2. Snout tip straight in lateral view, not raised. Dorsal profile from snout tip to posterior nasal plates straight, convex from frontals to nuchal plate, straight from predorsal plates to base of unbranched dorsal-fin ray, declined at dorsal-fin base, straight from end of dorsal-fin base to penultimate dorsal plate, elevated from last dorsal plate to end of caudal fin. Ventral profile from snout tip to anal-fin base convex, straight from that point to penultimate ventral plate, declined from last ventral plate to end of caudal fin.

Snout tip pointed in dorsal view, lateral margins of head straight. Odontodes of head and trunk small, thick, aligned. Dorsum of head rough; pronounced ridges between nostrils on posterior nasal plates to anterior margin of frontals, posterior to eyes on parieto-supraoccipital and compound pterotic; moderate ridges on anterior nasal plates, frontals, sphenotic, and compound pterotic. Infraorbital series with six bones, infraorbital 1 with a sensorial pore exposed ventrally, infraorbitals 2, 3, and 4 convexly raised from anterior portion of snout to eye. Rostral plate with an area without odontodes at tip of snout, narrow, horizontally elongated, short, not surpassing sensorial pore ventrally exposed of infraorbital 1. Posterior margin of parieto-supraoccipital slightly concave to straight, lateral margins truncate. Predorsal plates and first three lateral plates of dorsal series with pronounced ridges or keels. Superior margin of orbit raised, postorbital notch large. Eye large, rounded to slightly oval horizontally.

Lower lip narrow, ventral surface covered by short papillae with rounded tip, papillae slightly bigger at line bordering upper lip and close to dentary. Lower lip margin with mediumlengthed fringes; upper lip margin with short fringes. Maxillary barbel long, surpassing distal border of lower lip. Teeth bicuspid, long, mesial cusp greater and wider than lateral, dentary teeth larger than premaxillary. Premaxilla with 6(11), 7(27), 8(4), or 9(1) teeth; dentary with 6(11), 7(36), 8(11), or 9(2) teeth. Sexual dimorphism on teeth present (see sexual dimorphism). Branchiostegal rays 4(8).

Body narrow and short, four lateral plate series in longitudinal rows below dorsal fin: dorsal, median, mid-ventral, and ventral; mid-dorsal series absent ( Fig. 4a ). Median and mid-ventral series with rough well-developed keels; last plate of mid-ventral series extended around end of anal fin. Median series bearing sensory canal between two proximate keels on caudal peduncle.Longitudinal lateral plates 29(2), 30(12), 31(40), 32(19), or 33(2); posterior plates of median series 13(1), 15(12), 16(47), or 17(15). Lateral line complete.Lateral abdominal plates 4(2), 5(22), 6(45), or 7(6); borders of plates not in contact with lateral plates of mid-ventral series. Lateral region of body posterior to pectoral-fin insertion with a broad area of naked skin between borders of lateral plates of mid-ventral series and of lateral abdominal plates, thickness similar to caudal peduncle width ( Fig. 4a ). Abdominal plates of posterior complex with a large well-defined preanal plate bordered by three plates and these by five plates. Abdominal plates of median complex parallel and longitudinally arranged in three series posteriorly and in four series anteriorly. Abdominal plates of anterior complex irregular, smaller anteriorly, not projected toward lip; anterior margin convex, reaching horizontal line of anterior margin of cleithrum exposed ventrally.Vertebrae 26(1), 27(8), or 28(2); ribs 4(9) or 5(4).

Dorsal fin ii,7(68), dorsal-fin spinelet present, locking mechanism not functional; depressed unbranched ray reaching fourth to fifth plate posterior to its base, depressed incomplete. Immature specimens about 30 mm SL with pectoral, pelvic, dorsal, and anal fins light brown with dark brown spot on base of first rays, another spot on distal portions of first rays not reaching fin margin, distal spot extending to last ray forming transversal stripe; caudal fin almost totally dark brown except for a light brown blotch on anterior half of four median rays. Specimens about 45 mm SL with pectoral, pelvic, dorsal, and anal fins light brown with irregular dark brown blotches; caudal fin dark brown with narrow light brown band on anterior half. Adult specimens about 70 mm SL with pectoral, pelvic, dorsal, and anal fins light brown with irregular dark brown stripes, first branched rays with small dark brown spot on base and another distally, distal spot usually extended to last ray forming narrow transversal band; caudal fin with small dark brown spot on its base, middle region of branched rays light brown with irregular dark brown stripes, distal portion with broad, transverse, dark brown band, superior and inferior unbranched ray with irregular dark brown dots. See “Remarks” for description of the holotype.

Sexual dimorphism. Dissected females with mature oocytes at about 57 mm SL. Males showing sexually dimorphic odontodes at about 64 mm SL. Breeding male specimens with hypertrophied odontodes arranged on lateral margins and dorsum of head, last branched ray reaching third or fourth plate; dorsal-fin base with 3(1) or 4(76) plates; distal margin truncate. Pectoral fin i,6(69), depressed unbranched ray slightly surpassing pelvic-fin origin, distal margin truncate. Pelvic fin i,5(71), depressed unbranched ray slightly surpassing anal-fin origin, distal margin truncate.Anal fin i,5(69), depressed unbranched ray reaching sixth plate posterior to its base, depressed last branched ray reaching fourth to fifth plate; anal-fin base with two plates; distal margin truncate. Caudal fin emarginated, i,9,i(3) or i,10,i(63), superior unbranched ray extended as long filament similar in length to half SL.

Color in alcohol. Dorsal surface of body with light or dark brown ground coloration; ventral surface yellow or light brown, ventral plates posterior to pelvic fin with dark brown longitudinal spots forming stripes. Dorsal surface of head from anterior margin of snout to eyes with two longitudinal dark brown stripes. Lateral margins of head with irregular dark brown dots. Posterior region of parieto-supraoccipital with dark brown spot. Pores of sensorial canal of head and lateral line highlighted by black pigments. Dorsal surface of upper lip with two longitudinal light brown stripes, dorsal surface of lower lip with transverse light brown stripe. Dorsal surface of trunk with six narrow, transverse dark brown bands; first at dorsal-fin origin, oblique, extending toward last pectoral-fin ray; second just behind dorsal-fin base, broad, conspicuous; following bands similar, equidistantly separated and sometimes predorsal plates, and dorsal region of pectoral-fin rays ( Fig. 2 ); premaxillary and dentary teeth having its mesial cusp enlarged and rounded. Apparently, dimorphic odontodes develop first on lateral margins of head and on dorsum of pectoral fin, and later on dorsum of head and predorsal plates. Dimorphic odontodes on dorsum of head and predorsal region straight, thin, long, depressed, usually covered by skin at base, sometimes entirely covered, distributed in a large area over frontal, sphenotic, compound pterotic, parieto-supraoccipital, and predorsal plates. Dimorphic odontodes on lateral margins of head thin and long, tips hook-like curved, usually covered by skin at base, distributed over suprarostral plates, postrostral plates 2, 3, 4, subocular cheek plates 1, 2, and opercle. Dimorphic odontodes on dorsal region of pectoral branched rays thin, long, curved medially, distributed over almost entire portion of first to fifth rays and usually covered by skin at base; dimorphic odontodes of unbranched rays shorter and more densely arranged.

Distribution and habitat. Rineloricaria aurata is known from the Paraguay River basin in Paraguay and Brazil, and from the Guaporé River in Brazil ( Fig. 5 ). In Paraguay, this species were collected together with specimens of R. lanceolata and Farlowella paraguayensis along of the Jejuí and the Piribebuy drainages associated to leaves of partially submerged plants in small streams of clear and running waters.

Remarks. Knaack (2003) mentioned in the abstract of the original description of Rineloricaria aurata that a uniquely colored mailed catfish is described. This color pattern was characterized by a remarkably gold coloring of body dorsally and ventrally; black stains on dorsal-, pectoral-, ventral-, and anal-fin distal margins; a rounded black spot on the inferior lobe of the caudal fin; and irregular black marks before and below dorsal-fin insertion. The author stated that specimens changed their luminous intensity and mark designs according to environmental alterations of the aquarium and behavior condition, except for a black blotch posterior to the right eye in the holotype. In the preserved holotype, the black spot below right eye is still visible, marks on dorsal and pectoral fins are badly visible, marks before and below dorsal-fin insertion are brown reddish, and marks on nostrils, ventral, anal, and caudal fins are missing ( Fig. 6 ). We conclude that the author was based in peculiarities of the color pattern of one abnormal specimen to diagnose this species, which was preserved as the holotype and the unique type specimen. See “Discussion” for more details.

Examined material. Type specimens: ZMA 123591 , holotype, 83.0 mm SL, río Aquidaban, Dpto. de Concepcion, Strecke Loreto- San Carlos, Paraguay. Non-type specimens: Brazil: Mato Grosso State: CPUFMT 301 , 11 , 47.6-57.4 mm SL, CPUFMT 302 , 5 , 49.6-61.4 mm SL, CPUFMT 303 , 7 , 44.5-57.7 mm SL, CPUFMT 304 , 2 , 49.5 -46.0 mm SL, córrego Salobinho, Nobres. CPUFMT 305 , 1 , 54.7 mm SL, CPUFMT 306 , 1 , 71.8 mm SL, CPUFMT 307 , 3 , 57.3-59.4 mm SL (plus 1 ex. of R. lanceolata ), CPUFMT 308 , 5 , 49.3-62.7 mm SL (plus 3 ex. of R. lanceolata ), CPUFMT 309 , 4 , 58.4-68.3 mm SL (plus 2 ex. of R. lanceolata ), córrego Estorda, Diamantino. CPUFMT 316 , 2 , 59.9-60.6 mm SL (plus 1 ex. of R. lanceolata ), córrego Quebra-Canela, Diamantino. MCP 15794 , 1 , 81.7 mm SL, riacho Zé do Cacete, Cáceres. MCP 36520 , 1 , 50.5 mm SL, MCP 36525 , 7 , (1), 31.0- 54.4 mm SL, MCP 36526 , 1 , 44.4 mm SL, stream of the Poconé Pantanal, Poconé. MCP 36521 , 1 , (1), 76.8 mm SL, affluent of the rio Caeté , Cáceres. MCP 36522 , 6 , (4), 56.6-83.0 mm SL, riacho Figueira, Cáceres. MCP 36523 , 3 , 42.8-49.9 mm SL, affluent of the rio Aguapeí , Cáceres. MCP 36524 , 1 , 46.2 mm SL, affluent of the rio Cuiabá , Várzea Grande. MCP 36535 , 7 + 1 c&s of 13, (1), 46.7-63.3 mm SL, rio Papagaio , Pontes e Lacerda. MCP 36542 , 2 , (2), 68.3-70.1 mm SL, rio Galera , Pontes e Lacerda. MCP 36543 , 17 + 3 c&s of 37, (5), 51.3-68.8 mm SL, affluent of the rio Guaporé , Pontes e Lacerda. MCP 36546 , 5 + 1 c&s, (2), 44.6-81.4 mm SL, rio Novo , Nova Lacerda. MNRJ 20542 , 1 , (1), 79.3 mm SL, MNRJ 20543 , 3 of 6, (2), 61.8-74.6 mm SL, affluent of the rio Aricá-Açu , Cuiabá. MNRJ 21072 , 1 , 24.9 mm SL, rio Mutum , Dom Aquino. MZUEL 5149 , 27 , 25.2-56.7 mm SL, MZUEL 5158 , 44 , 26.6-51.5 mm SL, MZUEL 5159 , 2 , 32.4 - 40.0 mm SL, stream affluent of the rio Pixaim , Poconé. MZUEL 5151 , 1 , 47.5 mm SL, small lake of the rio Pixaim , Poconé. MZUSP 35909 , 1 , 55.0 mm SL, lake between rio Piquiri and rio Itiquira, Itiquira. MZUSP 44367 , 4 , 45.1-52.3 mm SL, stream of the Cáceres Pantanal, Cáceres. NUP 1011 , 1 , 46.2 mm SL, NUP 2269 , 9 , (3), 31.5-83.2 mm SL, NUP 3440 , 5 , (2), 63.2-74.1 mm SL, NUP 5407 , 6 , (1), 53.6-83.8 mm SL, NUP 5408 , 5 , (1), 62.1-70.6 mm SL, NUP 5409 , 3 , (2), 49.1-69.8 mm SL, NUP 5410 , 4 , 49.3-60.3 mm SL, NUP 5413 , 3 , (1), 55.6-78.5 mm SL, NUP 5414 , 12 , (1), 41.2-64.4 mm SL, NUP 5415 , 5 , (2), 56.9-75.7 mm SL, NUP 5416 , 21 , (1), 44.9-72.3 mm SL, NUP 5419 , 3 , (1), 59.3-84.7 mm SL, NUP 6111 , 1 c&s, 65.8 mm SL, NUP 6112 , 1 c&s, 85.5 mm SL, córrego Cancela, Nobres. NUP 2265 , 1 , 72.8 mm SL, NUP 2266 , 5 , 27.5 -76.0 mm SL, NUP 6110 , 1 c&s, 57.1 mm SL, córrego Forquilha, Rosário Oeste. NUP 2267 , 1 c&s, (1), 61.8 mm SL, NUP 5420 , 11 , 36.5- 49.1 mm SL, córrego Embaúba, Rosário Oeste. NUP 6113 , 1 , 50.4 mm SL, baía Santo Antônio, Barão de Melgaço. NUP 963 , 88 , (1), 23.9-74.2 mm SL, NUP 4539 , 3 , 42.1-48.5 mm SL, Manso Reservoir, Chapada dos Guimarães. Mato Grosso do Sul State: MZUEL 5150 , 2 , 35.5-37.2 mm SL, affluent of the rio Miranda , Corumbá. MZUEL 5154 , 1 , 79.4 mm SL, rio Miranda , Corumbá. MZUSP 48319 , 3 , 44.8-50.3 mm SL, bay at the Paiaguás Pantanal, Coxim. MZUSP 59349 , 10 of 26, 34.1-65.4 mm SL, rio Taboco , Aquidauana. MZUSP 59350 , 6 (plus 6 ex. of R. parva ), 40.0-53.0 mm SL, corixo Santo Antônio, Aquidauana. MZUSP 59368 , 1 (plus 1 ex. of R. parva ), 42.4 mm SL, rio Abobral 3, Corumbá. MZUSP 59369 , 1 (plus 1 ex. of R. parva ), 46.3 mm SL, rio do Peixe, Corumbá. MZUSP 59676 , 10 , 40.1-52.5 mm SL (pointed snout), stream of the Nhecolândia Pantanal, rio Negro. NUP 5893 , 1 , 44.8 mm SL, dike at Transpantaneira Road, Corumbá. ZUFMS-PIS 656 , 8 (plus 1 ex. of R. parva ), 32.1-54.4 mm SL, baía das Pedras, Corumbá. Paraguay: Departamento de Alto Paraguay: MNHNP 3673 , 1 , 58.2 mm SL, río Paraguay, Fuerte Olimpo. MNHNP 3674 , 1 , 53.3 mm SL, río Paraguay, Puerto 14 de mayo. NRM 33313 , 1 (plus 30 ex. of R. parva ), 58.1 mm SL, río Paraguay, Bahia Negra. NRM 37673 , 2 (plus 11 ex. of R. parva ), 52.2-58.5 mm SL, río Paraguay, Bahia Negra. Departamento de Amambay: MNHNP 2662 , 5 , 44.5-64.5 mm SL, affluent of the río Apa , Bella Vista. Departamento de Caaguazú: NRM 42111 , 2 , 54.0- 67.5 mm SL, affluent of the río Tebicuary-mí , Coronel Oviedo. NRM 42849 , 8 , (4), 23.5-72.0 mm SL, affluent of the río Yhaguy , San José. Departamento de Canindeyú: MNHNP 474 , 2 , (1), 42.7-68.4 mm SL, affluent of the río Jejuí , San Isidro de Curuguaty. MNHNP 1589 , 1 , 46.9 mm SL, tributary of the río Jejuí , San Isidro de Curuguaty. MNHNP 2866 , 1 , (1), 73.4 mm SL, affluent of the río Jejuí , Colonia Lomas Valentinas. MNHNP 3608 , 1 , 53.4 , río Jejuí-mí , Reserva Natural del Bosque Mbaracayú. MNHNP 3669 , 1 c&s, 72.0 mm SL, arroyo Pira-Cajón, Reserva Natural del Bosque Mbaracayú. NRM 22472 , 1 , (1), 66.6 mm SL, NRM 32580 , 3 , (2), 45.0- 59.6 mm SL, río Jejuí-mí , Curuguaty. UMMZ 206295 , 1 (plus 19 ex. of R. lanceolata ), 42.2 mm SL, arroyo Carimbatay, Curuguaty. Departamento de Concepción: MNHNP 510 , 2 , (1), 50.4-65.6 mm SL, Tagatiyá-Mí, Paso Barreto. MNHNP 3664 , 3 , (1), 47.2-64.4 mm SL, Tagatiyá-Mí, Paso Barreto. MNHNP 3670 , 1 c&s, 67.1 mm SL, affluent of the río Apa , Parque Nacional Paso Bravo. MZUSP 54228 , 2 , (2), 56.1-62.3 mm SL, río Aquidabán , Concepción. NRM 23028 , 1 (plus 11 ex. of R. parva ), 38.9 mm SL, arroyo Laguna Penayo, Paso Barreto. NRM 32584 , 3 , (2), 63.9-65.9 mm SL, arroyo Laguna Penayo, Paso Barreto. Departamento de Cordillera: ANSP 164276 , 1 , (1), 69.1 mm SL, possibly Caacupé. CZCEN 315 , 1 c&s, 60.2 mm SL, affluent of the río Yhaguy , Caraguatay. MNHNP 3655 , 5 , (1), 47.8-60.5 mm SL, MNHNP 3675 , 1 , 71.4 mm SL, NRM 41822 , 3 , (1), 46.4-60.3 mm SL, arroyo Piribebuy, Eusebio Ayala. Departamento de Guairá: MNHNP 3676 , 2 , 39.7 -48.0 mm SL, affluent of the río Tebycuary-Mí, Colonia Natalicio Talavera. NRM 42354 , 6 (plus 31 ex. of R. lanceolata ), 21.7-25.9 mm SL, arroyo Guazú , Independencia. Departamento de San Pedro: ANSP 175152 , 20 , (4), 12.7-76.9 mm SL, swamp of the río Maduvirã , Yataity del Norte. CZCEN 326 , 5 , 47.6-79.2 mm SL, arroyo Maya , San Pedro del Ycuamandiyú. MNHNP 384 , 2 , (2), 71.5-73.7 mm SL, río Mboi , Colonia Coé Pytã. MNHNP 385 , 2 , (2), 69.5-73.5 mm SL, río Mboi , Colonia Coé Pytã. MNHNP 1221 , 1 , 46.1 mm SL, arroyo Aguaray-Mí. MNHNP 1583 , 1 , (1), 57.7 mm SL, arroyo Clementina , Santa Rosa. NRM 22285 , 1 , (1), 71.0 mm SL, río Jejuí , Mbutuy. NRM 33590 , 1 , 67.9 mm SL, arroyo Clementina , Santa Rosa. UMMZ 206604 , 20 of 45, (10), 51.0- 75.3 mm SL, río Aguaray , city not specified .

Figures

Fig. 3. Rineloricaria aurata, NUP 3440, male, 74.1 mm SL, córrego Cancela, affluent of the rio Cuiabá, Paraguay River basin, Nobres, Mato Grosso State, Brazil.

Fig. 4. Lateral plate series in three Rineloricaria species: a) R. aurata, b) R. eigenmanni, c) R. hasemani. See also the region posterior to the pectoral-fin insertion, which shows a broad area of naked skin in the Fig. 4a, and a slender area in Figs. 4b and 4c. P = Pectoral-fin insertion, LAP = Lateral abdominal plates.

Fig. 5. Partial map of SouthAmerica showing the geographical distribution of Rineloricaria aurata. Dot = Occurrence. Star = Type locality (Aquidabán River, Concepción, Departamento de Concepción, Paraguay).

Fig. 6. Holotype of Rineloricaria aurata, ZMA 123591, male, 83.1 mm SL, Aquidabán River, tributary of the Paraguay River, Concepción, Departamento de Concepción, Paraguay.

Fig. 12. Hypetrophied odontodes developed in breeding male specimens of Rineloricaria parva, ZUFMS-PIS 567, 94.3 mm SL: a) dorsal view, b) lateral view, c) ventral view.

Fig. 2. Plots of scores obtained by Principal Components Analysis. a) Three populations of Rineloricaria lanceolata (Triangles = Upper Amazonas River, Asterisks = Araguaia River, Dots = Middle Amazonas River and tributaries) and one population of Rineloricaria hoehnei (Squares = Paraguay River basin). b) Rineloricaria aurata (Squares), Rineloricaria cacerensis (Dots), Rineloricaria lanceolata (Triangles), and Rineloricaria parva (Filled squares).