Anostomoides nattereri ( Steindachner, 1876 )

Assega, Fernando Massayuki & Birindelli, José Luís Olivan, 2019, Taxonomic revision of the genus Anostomoides (Characiformes: Anostomidae), Zootaxa 4646 (1), pp. 124-144 : 136-139

Anostomoides nattereri ( Steindachner, 1876)

( Figs. 1 , 2B , 3B , 4 C , 7 , 8 ; Tables 1 and 3)

Leporinus nattereri Steindachner, 1876: 114-117 (type locality: “Mündung des Rio Negro und bei Teffé in den Ausständen des Amazonenstromes…und im Lago Alexo”, Brazil).— Garavello & Britski, 2003: 77 (checklist; Essequibo, Orinoco and Solimões rivers).

Anostomoides passionis Santos & Zuanon, 2006: 61-66 , figs. 2 and 3 (diagnosis, description, diagnosis; photos, dentition; ecological notes; type locality: “ Brasil, State of Pará: Rio Xingu, Viracebo do Arroz Cru (03º25’15.7’’S, 51º55’08.3’’W).— Ohara et al., 2017: 34 (brief description, photo, diagnosis in key; Brazil, Rio Teles Pires).— Sidlauskas & Birindelli, 2017: 85 (cited). [New synonym].

Anostomoides sp. 1.— Santos & Jegú, 1989: 165, fig.; pl. V, fig. 2, 3, 4 and 19 (brief description, diagnosis in key; photo, dentition; lower Rio Tocantins, Brazil).

Diagnosis. Anostomoides nattereri differs from A. atrianalis by having four branchiostegal rays (vs. three), three pores in the infraorbital one (vs. four); symphyseal tooth of premaxillary with blunt border (vs. bicuspid); lower count of lateral line scales (37–39 vs. 41–44); lower jaw lip with rounded dermal papillae (vs. papillae forming ridges) ( Fig. 4 ); three dark rounded midlateral blotches (vs. three or four vertically elongated blotches and/or a faded dark longitudinal stripe), dark lines between scale series on posterior half of body in specimens smaller than 150 mm SL (vs. dark lines absent in specimens of all sizes).

Description. Body elongate, lateraly compressed, greatest body depth at dorsal-fin origin ( Table 3). Dorsal profile gently sloped and convex from snout to dorsal-fin base; slightly slanted and convex along dorsal-fin base; somewhat straight or slightly convex from end of dorsal fin to adipose-fin origin, and concave from that point to origin of dorsal procurrent caudal-fin rays ( Fig. 7 ). Ventral profile slanted convex from tip lower jaw to vertical through pectoral-fin origin; slightly convex from vertical through pectoral-fin origin to anal-fin origin; slightly convex along anal-fin base, and somewhat concave from anal-fin end to origin of ventral procurrent caudal-fin rays; caudal peduncle sligthly compressed, almost rectangular and slightly longer than deep.

Head pointed in profile and laterally compressed; snout relatively long. Mouth slightly upturned; lips thick and fleshy, covered internally with numerous papillae. Four premaxillary teeth, symphyseal tooth larger, wider, border slightly convex, remaining teeth with medial cusp often sided by small lateral saliencies forming incipient cusps. Four dentary teeth gently decreasing in size laterally, two medial teeth with blunt cutting edge, and two lateral teeth with medial cusp often sided by one to four diminutive cups. Upper and lower jaw lips covered with rounded (conical or hemi-cylindrical) dermal papillae ( Fig. 4 ). Four branchiostegal rays.

Scales large and cycloid. Lateral line complete with 37(3)*, 38(48) or 39(1) perforated scales, extending from supracleithrum to basis of middle caudal-fin rays. Horizontal scale rows between dorsal-fin origin and lateral line 5(2), 6(32) or 7(9). Horizontal scale rows between lateral line and pelvic-fin origin 5(27) or 6(15). Horizontal scale rows around caudal peduncle 16(51)*. Predorsal scales from dorsal-fin origin to tip of supraoccipital spine 12(10), 13(11), 14(7), 15(8) or 16 (6).

Dorsal-fin rays ii, 9(3), ii, 10(39), ii, 11(9)* or iii, 11(1). Dorsal-fin origin slightly anterior to middle of standard length; distal margin of dorsal fin straight or gently concave. Adipose fin small, slightly rectangular shaped, its origin approximately at vertical through half of anal-fin base length. Pectoral-fin rays i, 12(1), 14(34)* or 15(17); its tip extending more than half distance between origins of pectoral and pelvic fins; pectoral-fin base slightly convex; its distal margin slightly convex. Pelvic-fin rays i, 8(51)*; with distal margin slightly convex. Anal-fin rays ii, 8(4), iii, 8(37), ii, 9(5)* or iii, 9(5); its origin approximately at vertical through fifth scale anterior to adipose-fin origin; distal margin of anal fin straight or gently concave. Principal caudal-fin rays i, 9+8,i (51)*. Caudal fin forked, upper lobe slightly longer than lower lobe.

Coloration in alcohol. Body with background color light brown to beige ( Fig. 7 ). Body with three inconspicuous midlateral rounded dark brown blotches in small specimens (up to 200 mm SL): first one below dorsal-fin base; second blotch above anal-fin origin; third blotch at caudal peduncle terminus. Body with two conspicuous round dark midlateral in large specimens (above 200 mm SL): first blotch below dorsal-fin base; second above anal-fin origin. Dark midlateral rounded blotches covered by epidermal dark pigmentation in large specimens (above 200 mm SL). Posterior portion of body (from vertical through dorsal-fin origin to terminus of caudal peduncle) with dark lines between scale series in specimens smaller than 150 mm SL. Dorsal fin with rays and interradial membranes pale on proximal portion and dark on median and distal areas, or uniformely tan. Caudal, pectoral and pelvic fins uniformly tan. Anal fin with rays and interradial membranes pale on proximal area and dark on median and distal area. Adipose fin with base and lobe pale, except median portion, which is light dark.

Distribution. Anostomoides nattereri is distributed in the Orinoco basin in Venezuela, and across the Amazon basin in Brazil, where it is recorded for the following tributaries: Negro, Tefé, Tapajós, Tocantins and Xingu river basins, Brazil ( Fig. 8 ).

Common names. “Aracu vermelho” ( Santos et al., 2004), “piau do sarão” ( Santos & Zuanon, 2006).

Remarks. Steindachner (1876) described Leporinus nattereri based on several specimens from the Amazon basin. The name Leporinus nattereri is occasionally cited in regional checklists (e.g., Lasso et al., 2004; Maldonado- Ocampo et al., 2008; Sarmiento et al., 2014), but it cannot be assumed that these citations truly refer to specimens conspecific with the species described by Steindachner (1876), and they should be considered as doubtful.

All 12 syntypes of Anostomoides nattereri deposited in the MCZ and in the NMW were examined. Even though the type specimens of A. nattereri include several individuals collected in distinct sites, they are in fact all conspecific. One relatively large (104.9 mm SL), well-preserved specimen from Tefé ( NMW 68346) is herein selected as the lectotype, with the remaining syntypes becaming, thus, paralectotypes.

Steindachner (1876: 117) cited that type specimens from the mouth of the Rio Negro and from Tefé were collected by Johann Natterer. However, J. Natterer did not travelled in the Rio Amazonas upstream from Manaus (see Vanzolini, 1993), and consequently, contrary to what was reported by Steindachner (1876), did not collected fishes in the Rio Tefé area. These type specimens were probably collected by the Thayer Expedititon, which collected at the Tefé area between September and October, 1865 (see Higuchi, 1996). Herein, we selected the best preserved syntype as the lectotype, thus restricting the type locality of A. nattereri for the Rio Tefé.

Material examined. Type material: NMW 68346, 1, 104.9 mm SL, Brazil, Amazonas , Rio Tefé, presumably L. Agassiz, Thayer Expedition, October 1865 (see above); lectotype of Leporinus nattereri , by present designation . NMW 68346b, 1, 101.2 mm SL, same data as NMW 68346; paralectotype of Leporinus nattereri Steindachner . MCZ 20384, 3 , 79.0–103.0 mm SL, Brazil, Amazonas , confluence between the Rio Tefé and Rio Solimões (03°24’ S, 64°45’ W), L. Agassiz, Thayer Expedition, October 1865, paralectotypes of Leporinus nattereri Steindachner ; NMW 68344, 3 , 79.9–86.9 mm SL ; NMW 68345, 4 , 67.2–81.3 mm SL; Brazil, Amazonas , Lago Aleixo, L. Agassiz, Thayer Expedition, 1874; paralectotypes of Leporinus nattereri Steindachner ; INPA 13182 , 1 , 265.0 mm SL, Brazil, Pará , Rio Xingu, Viracebo do Arroz Cru (03°25’15” S, 51°55’08” W); G.M. Santos & J. Zuanon, 17 September 1997; holotype of Anostomoides passionis . INPA 4043 , 2 , 229.6 – 268.2 mm SL, same as INPA 13182 ; MZUSP 86023 , 1, 268.4 mm SL same data as INPA 13182 . Paratypes of Anostomoides passionis .

Material Examined. Non-types. Brazil: Amazonas : INPA 14042 , 1 , 88.5 mm SL, Manaus, Rio Branco , C.C. Fernandes, 15 November 1992 ; MZUSP 14452 , 1, 193.3 mm SL, Manaus, Rio Negro, Igarapé Jaraqui (03°00’ S, 60°24’ W), Expedição Permanente à Amazônia, April 1967 ; INPA 14043 , 1 , 89.0 mm SL, Manaus, Rio Negro, right margin, near the confluence with Rio Branco , M.Souza, 28 September 1997 ; NMW 87756, 1 , 163.0 mm SL, Tefé, mouth of Rio Negro ; MZUSP 77615 , 1, 170.3 mm SL, São Gabriel da Cachoeira, Rio Negro, Igapó (00°07’ S, 67°05’ W), M. Goulding, 18 May 1979 . Maranhão: UNT 83 , 2 , 215.0– 236.3 mm SL, Estreito, Rio Tocantins, near the confluence with the Rio Itaueira (06°30’ S, 47°25’ W) , NEAMB–UFT, 29 June 2000 ; MNRJ 39644 , 1 , 213.0 mm SL, Estreito, Rio Tocantins, Usina Hidrelétrica de Estreito (cofferdam), D.F. Morais, E. Dubanskas & M. Senna, 06 March 2010 . Mato Grosso: INPA 45078 , 1, 162.1 mm SL, Paranaíta, Rio Teles Pires , downstream of Sete Quedas rapids, S. Arrolho et al., February 2014 ; MZUSP 54551 , 1, 163.2 mm SL, São Francisco do Araguaia, Rio Araguaia ; R. Silvano, February 1998 . Pará : MZUSP 110595 , 2 (Sk), 230.0–232.0 mm SL, Altamira, Rio Bacajai (03° 52’ 11” S, 51° 52’ 48.0” W), O.T. Oyakawa, J.L.O. Birindelli, C. Moreira, A. Akama, L. Sousa & H. Varella, 19 November 2000 ; MZUSP 105643 , 1, 239.6 mm SL, Altamira, Rio Xingu, Caitucá (03° 33’ 44” S, 51° 52’ 37” W), Equipe de Ictiologia da UFPA, 05–06 November 2000 ; INPA 47730 , 1 , 81.3 mm SL, Altamira, Rio Xingu, approximately 4 km above the confluence with the Rio Iriri (03°51’08” S, 52°35’17” W), M. Sabaj, 02 November 2014 ; INPA 47181 , 1, 256.3 mm SL, Altamira, Rio Xingu, beach at 59 km from Altamira (03°35’01” S, 51°49’23” W), M. Sabaj, 10 November 2014 ; INPA 40489 , 1 , 88.8 mm SL, Anapu, Rio Xingu, below Volta Grande , near Cachoeira Camaracá (03°07’13” S, 51°38’01” W), M. Sabaj, 21 September 2013 ; INPA 40753 , 5 , 78.1 –176.0 mm SL, Anapu, Rio Xingu, below Volta Grande (03°11’03” S, 51°37’02” W), M. Sabaj, 28 September 2013 ; INPA 40840 , 1, 264.4 mm SL, Anapu, Rio Xingu, below Volta Grande and Cachoeira Tamaracá (03°07’41” S, 51°37’17” W), M. Sabaj, 01 October 2013 ; LIA 1229 , 1, 175.5 mm SL, São Félix do Xingu, Rio Pedra Preta 06°43’29.35”S, 51°58’54.12” W), L. Souza, A. Gonçalves & C. Martins, 22 September 2014 ; LIA 1157 , 1, 104.6 mm SL, São Félix do Xingu, Rio Remansinho (06°55’58.48”S, 52°08’13.45” W), L. Souza, A. Gonçalves & C. Martins, 23 September 2014 . MPEG 19714 , 1 , 94.2 mm SL, Itaituba, Rio Tapajós , vila de Miritituba (04°17’13.8” S, 55°57’36.2” W), C.S. Ramos, 09 July 2010 ; INPA 1613 , 2 , 95.1–155.2 mm SL, Itupiranga, Rio Tocantins (05º 09’ S, 49º 21’ W), G.M. Santos, 01 September 1980 ; INPA 24014 , 1, 207.2 mm SL, Nova Ipixuna, Rio Tocantins, reservoir of Tucuruí dam, G.M. Santos, 07 October 2004 ; INPA 53134 , 1, 186.3 mm SL, Tucuruí, Rio Tocantins, reservoir of Hidrelétrica Tucuruí , base II (03º56’ S, 49º36’ W), G.M. Santos, September 1984 ; INPA 2501 , 1, 195.2 mm SL, Tucuruí, Rio Tocantins, F. Martinho, 31 May 1988 ; INPA 20565 , 1 , 232.0 mm SL, Tucuruí, Rio Tocantins, downstream from the dam Usina Hidrelétrica de Tucuruí (03°45’30” S, 49°39’10” W), Equipe Eletronorte, 16 May 2000 ; INPA 24013 , 2 , 207.2 – 216.2 mm SL,, same locality as INPA 20565 , G.M. Santos , 27 October 2004 ; MZUSP 5429 , 6 (1 Sk), 131.9–169.5 mm SL, Oriximiná, Rio Trombetas (01°46’ S, 55°52’ W), Expedição Permanente à Amazônia, February–March 1967 . Tocantins: NUP 8383, 1, 177.8 mm SL, Tocantins, Xambioá , Rio Araguaia (06°25’49” S, 48°34’32” W), GERPEL, 23 March 2009 . Venezuela: ANSP 165820 , 1, 214.2 mm SL, Amazonas, Río Iguapo, tributary of Río Orinoco (03°09’N 65°28’W), H. Lopez, J. Fernandez, O. Castillo, M.E. Antonio & J. Moreno, 13 March 1987 ; ANSP 159351 , 4 , 73.2–83.3 mm SL ; ANSP 159604 , 18 , 77.4–119.8 mm SL, Bolivar, Caño Curimo (possibly), tributary of Río Caura, near confluence of Río Orinoco (07°37’48”N 64°50’42”W), B. Chernoff, W.Saul & R. Royero, 22 November 1985 ; ANSP 160348 , 18, 68.0– 143.9 mm SL, Bolivar, confluence of Río Orinoco and Río Caura ( Las Piedras ) (07°38’36”N 64°50’00”W), W. Saul, R. Royero & L. Aguana, 23 November 1985 .

Figures

FIGURE 1. Scatter diagram of scores of specimens on second and third axes of Principal Components Analysis (PCA) of Anostomoides atrianalis from the Amazon basin (blue square), Essequibo River, Guyana (fill blue square), and Orinoco basin (black dot), A. nattereri from the Rio Xingu (yellow triangle), and A. nattereri from the Orinoco and remaining Amazon basin (filled pink square).

FIGURE 2. Lateral view of head showing the position of the mouth, upturned (A and C), slightly upturned (B) and terminal (D). (A) Anostomoides atrianalis, ANSP 182467, 128.3 mm SL, Peru, Loreto, Río Nanay; (B) A. nattereri, LIA 1229, 175.5 mm SL, Brazil, Pará, Rio Xingu; (C) Laemolyta proxima, MZUEL 17132, 215.5 mm SL, Brazil, Amazonas, Manaus; (D) Leporinus fasciatus, MZUEL 14698, 136.3 mm SL, Brazil, Amazonas, Rio Negro. Scale bar = 10 mm.

FIGURE 3. Scanning electron microscope image of left upper and lower jaws of Anostomoides: (A) A. atrianalis, INPA 15193, 137.2 mm SL; (B) A. nattereri, MZUSP 5429, 89.0 mm SL.

FIGURE 4. Lateral view of the head showing thickened, fringed lips with numerous dermal papillae in: (A) Anostomoides atrianalis, ANSP 159599, 132.8 mm SL, (B) Leporinus fasciatus, ANSP 161713, 189.9 mm SL, (C) Anostomoides nattereri, FMNH 103451, 141.8 mm SL, (D) Synaptolaemus latofasciatus, ANSP 190764, 80.2 mm SL. Scale bar = 5 mm.

FIGURE 7. Anostomoides nattereri from the Amazon basin (A and B) and Rio Xingu (C, D and E): (A) lectotype of A. nattereri, NMW 68346, 104.9 mm SL, Brazil, Amazonas, Rio Tefé; (B) MPEG 19714, 94.2 mm SL, Brazil, Pará, Rio Tapajós; (C) holotype of A. passionis, INPA 13182, 265.0 mm SL, Brazil, Pará, Rio Xingu; (D) paratype of A. passionis, INPA 14876, 161.0 mm SL, Brazil, Pará, Ponta da ilha da Bela Vista; (E) INPA 47730, 81.3 mm SL, Brazil, Pará, Rio Xingu. Scale bars = 10 mm.

FIGURE 8. Geographic distribution of species of Anostomoides nattereri: red star: type locality of A. nattereri; white star: type locality of A. passionis; and red diamond: records of A. nattereri. Some symbols may correspond to more than one locality.