Leporinus inexpectatus, Britski & Garavello & Oliveira & Birindelli, 2024

Leporinus inexpectatus , new species ( Fig. 3 View Figure 3 )

Leporinus aff. bahiensis . – Géry et al., 1987: 387, fig. 16 [in part; Paraguay; Río Acaray (and Arroyo Yuquyri, a stream of the latter), tributary of the Rio Paraná, a few kilometers below Itaipu dam, and Río Itapo-Guazu and Arroyo Pyrapyta, tributaries of the Itaipu reservoir].

Leporinus paranensis View in CoL . – Garavello & Britski, 1987: 156, [in part, MZUSP 14455, MZUSP 37406, MZUSP 37407, MZUSP 37408, MZUSP 37409, MZUSP 37411]. – Oyakawa, 1996: 476-477 [type catalog, in part, MZUSP 14455, MZUSP 37406, MZUSP 37407, MZUSP 37408, MZUSP 37409, MZUSP 37411]. – Durães et al., 2001: 184 [Rio Araguari, Minas Gerais]. – Castro et al., 2003: 13, figs. 6-18 [tributaries of the Rio Paranapanema, LIRP 2254]. – Britto & Carvalho, 2006: 382 [Rio Paranapanema at TaquaruÇu reservoir]. – Langeani et al., 2007: 184 [upper Paraná, considered autochthonous and native; DZSJRP 22]. – Brandão et al., 2009: 454 [Rio Novo, tributary of Rio Paranapanema, LBP 4845]. – Reis et al., 2020: 457 [list of species from Paraná state].

Leporinus aff. paranensis View in CoL . – Langeani et al., 2007:196 [species mentioned as being described by Heraldo Britski]. – Avelino et al., 2015: 101 [molecular data, COI sequence, LBP 3808].

Type specimens

Holotype: MZUEL 14311, 155.6 mm SL, São Paulo state, Euclides da Cunha Paulista municipality, Córrego Água Branca, tributary of Rio Paranapanema, 22°29′34.1″S 52°32′32.8″W, M. Rocha, J.L.O. Birindelli, F.C. Jerep & E. Santana, 14 Jan 2016. GoogleMaps

Paratypes: Brazil, Paraná state. LIRP 2254, 1 alc, 97.9 mm SL, Paranavaí, Córrego Santa Clara at Fazenda Rancho Zinco e Cristo Rei, Paranapanema drainage, 22°45′54″S 52°25′19″W, R.M.C. Castro et al., 08 Aug 2000. MZUEL 6517, 2 alc, 46.9-56. 7 mm SL, Sertanópolis, Ribeirão Couro do Boi, tributary of Rio Tibagi, 23°05′39.2″S 50°59′49.6″W, L.C. Silva, E. Santana, A. Souza, 21 Oct 2010. MZUEL 8807, 1 alc, 57.1 mm SL, Sertanópolis, Ribeirão Couro do Boi, tributary of Rio Tibagi, 23°05′39.2″S 50°59′49.6″W, L.C. Silva, E. Santana, A. Souza, 29 Mar 2010. MZUEL 8902, 1 alc, 43.6 mm SL, Sertanópolis, Ribeirão Couro do Boi, tributary of Rio Tibagi, 23°05′39.2″S 50°59′49.6″W, L.C. Silva, E. Santana, A. Souza, 20 May 2009. Brazil, São Paulo state. DZSJRP 10948, 3 alc, 47.1-65. 5 mm SL, Brejo Alegre, F.B. Teresa and J.L. Veronezi, 29 Sep 2007. LBP 3808, 5 alc, 14.0-19. 8 mm SL, Avaré, Rio Novo, tributary of Rio Paranapanema, 23°01′26.2′W 48°49′32.6″. LBP 4845, 2 alc, 16.7-19. 1 mm SL, Salto Grande, Rio Paranapanema, at Salto Grande reservoir, 22°50′23″S 49°50′50″W. LIRP 2252,11 alc, 50.3-155.0 mm SL,Santo Antônio do Aracangua, Córrego das Cruzes, Tietê drainage, 20°48′44″S 50°41′16″W, R.M.C. Castro et al., 06 Sep 1999. LIRP 7626, 1 alc, 96,6 mm SL, Gavião Peixoto, Rio Jacaré-GuaÇu, Tietê drainage, 21°50′46″S 48°31′28″W, A. Esguícero, 04 Jan 2010. MZUSP 48852, 5 alc, 84.3-123.0 mm SL, Córrego Fundo, Murutinga do Sul, Atílio Storti, 28 Mar 1975. MZUSP 71790, 2 alc, 90.6-95. 2 mm SL, Rio do Peixe, approximately 1.5 km below UHE Rio do Peixe, São José do Rio Pardo, Pedro Gehard, 10 Jan 2001.

Non-type specimens: Brazil, Minas Gerais state. MZUSP 36777, 2 alc, Ituiutaba, Rio Tejuco at Salto do Morais, 18°56′S 49°48′W,A.L.Godinho, Oct 1985 to Feb 1986. Brazil, São Paulo state. FMNH 71240, 1, 39.4 mm SL, Barbosa, Rio Tietê at Salto do Avanhadava, c. 21°13′S 49°56′W, J.D. Haseman, 14 Sep 1908. MZUSP 14455, 4 alc [paratypes of L. paranensis ], 92.0-102.0 mm SL, Murutinga do Sul, Córrego Fundo, c. 21°37′S 47°20′W, A. Storti, 24 Dec 1974. MZUSP 37406, 1 alc [paratype of L. paranensis ], 97.0 mm SL, Araraquara, Rio Jacaré GuaÇu, at road between Araraquara and Guarapiranga, 21°53′38″S 48°15′01″W, J. R. Moreira, 15 Feb 1985. MZUSP 37407, 1 alc [paratype of L. paranensis ], 119.0 mm SL, Rio Paranapanema, J.C. Garavello, 14-20 May 1979. MZUSP 37408, 1 alc [paratype of L. paranensis ], 123.0 mm SL, Araraquara, Rio Jacaré GuaÇu at small waterfall upstream of PCH Gavião Peixoto dam, c. 21°50′S 48°29′W, J. R. Moreira, 13 Mar 1984. MZUSP 37409, 1 alc [paratype of L. paranensis ], 146.0 mm SL,Araraquara,Rio Jacaré GuaÇu at Fazenda Alabama, upstream of PCH Gavião Peixoto dam, c. 21°50′S 48°29′W, J. R. Moreira, 13 Mar 1984. MZUSP 37411, 1 alc [paratypes of L. paranensis ], 129.0 mm SL, Araraquara, Rio Jacaré GuaÇu, at Fazenda Alabama, upstream of Gavião Peixoto dam, c. 21°50′S 48°29′W, J. R. Moreira, 30 Apr 1985. Paraguay. All from Dept. Alto Parana, c. 25°27′S 54°38′W. MHNG 2004.97, 1 alc, 142.0 mm SL, río Acaray, C. Dlouhy, 21 Oct 1978. MHNG 2037.19-23, 5 alc, 79.0-105. 2 mm SL, Porto Ponte Stroessner, C. Dlouhy, 11 Apr 1980. MHNG 2067.94, 1 alc, 112 mm SL, Río Itabo-Guazu, C. Dlouhy, 06 May 1980. MHNG 2105.63-64, 2 alc, 109.0-134. 6 mm SL, Ao. Acaray, C. Dlouhy, 15 Sep 1981. MHNG 2105.65-66, 2 alc, 113.0-127. 5 mm SL, Lac Represso, C. Dlouhy, 07 Sep 1982. MHNG 2159.20, 1 alc, 110.0 mm SL, Ao. Pyrapyta, C. Dlouhy, 03 Oct 1981. MHNG 2204.24, 5 alc, 89.0-98. 3 mm SL, Alto Paraná, Lac Acaray, C. Dlouhy, 03 May 1984. MHNG 2386.53, 5 alc, 101.2-133. 5 mm SL, Lac Acaray, Expct. Zool. Mus. Genève, 1986? MHNG 2386.54, 1 alc, 100.6 mm SL, Ao. Itaquyry, Expdt. Zool. Mus. Genève, 16 Oct 1986. MHNG 2386.54, 1 alc, 152.5 mm SL, Río Acaray, Expdt. Zool. Mus. Genève, 31 Oct 1986. MHNG 2386.92, 2 alc, 131.0-139.0 mm SL, Lac Acaray superior, Exped. Zool. Mus. Genève, 1986. MHNG 2396.62, 1 alc, 142.5 mm SL, Lagune Ao. Iguassu à Juan E.O. Leary, Expdt. Zool. Mus. Genève, 18 Oct 1987.

Remarks: The paratypes of Leporinus paranensis MZUSP 14456 (16 alc), and MZUSP 37410 (1 alc), that likely belonged to Leporinus inexpectatus , were not found at MZUSP ( Oyakawa, 1996: 477). Géry et al. (1987: 387) mention a juvenile (c. 55 mm SL) from Río Negro, 6 km north of Chaco-I, Paraguay basin, Paraguay, as belonging to Leporinus aff. bahiensis (= L. inexpectatus ). This specimen was examined by one of us (HAB) and likely belongs to Leporinus lacustris because it has four teeth on each premaxillary and dentary, in addition to the three dark midlateral blotches, 34 lateral-line scales and 16 scale series around the caudal peduncle. Interestingly, the first specimen of Leporinus inexpectatus deposited in fish collections was sampled in 1908 (FMNH 71240),more than a hundred years ago,by J.D. Haseman in the Salto do Avanhadava, a waterfall that was flooded by a hydroelectric plant during the 1970′s.

Diagnosis: Leporinus inexpectatus is distinguished from congeners, except L. amae , L. amblyrhynchus , L. bahiensis , L. bistriatus , L. bleheri , L. desmotes , L. enyae , L. guttatus , L. marcgravii , L. melanopleura , L. microphthalmus , L. microphysus , L. moralesi , L. multimaculatus , L. octofasciatus , L. octomaculatus , L. paranensis , L. reticulatus , L. sexstriatus , L. striatus , L. taeniatus , L. taeniofasciatus , L. torrenticola , and L. tigrinus by having threepremaxillaryteeth(vs.four). Leporinusinexpectatus is distinguished from L.amae , L.amblyrhynchus , L. bistriatus , L. bleheri , L. desmotes , L. enyae , L. guttatus , L. marcgravii , L. melanopleura , L. microphthalmus , L. microphysus , L. moralesi , L. multimaculatus , L. octofasciatus , L. octomaculatus , L. reticulatus , L. sexstriatus , L. striatus , L. taeniatus , L. taeniofasciatus , L. torrenticola , and L. tigrinus by having three dark midlateral blotches on the body (vs. body with dark transversal bars in L. bleheri , L. desmotes , L. enyae , L. octofasciatus , L. tigrinus , or body with a dark midlateral stripe in L. amae , L. amblyrhynchus , L. bistriatus , L. melanopleura , L. melanoplerodes , L. microphysus , L. moralesi , L. sexstriatus , L. sidlauskasi , L. striatus , L. taeniatus , L. taeniofasciatus , or body with four to eight dark midlateral blotches in L. guttatus , L. marcgravii , L. microphthalmus , L. multimaculatus , L. octomaculatus , L. reticulatus , L. torrenticola ). Leporinus inexpectatus is distinguished from L. paranensis by having 12 scale rows around caudal peduncle (vs. 16); and from L. bahiensis by having a terminal mouth (mouth cleft longitudinally aligned with ventral border of eye) in specimens larger than 100 mm SL (vs. subterminal, mouth cleft longitudinally aligned with ventral border of infraorbital series), body pale brown to silver and slightly yellow to hyaline fins in life (vs. body dark brown and bright orange fins in life).

Description: Morphometric data in Table 2. Medium-sized species, largest known specimen 155.6 mm SL. Head and trunk elongate and moderately compressed. Dorsal profile slightly arched from anterior margin of snout to dorsal-fin insertion; declining in an almost straight line from dorsal-fin origin to adipose fin; and concave at caudal peduncle. Ventral profile in a slight convex line from lower jaw to anal-fin insertion; straight on anal-fin base, and concave on caudal peduncle. Body depth greatest at origin of dorsal fin.

Mouth terminal, opening horizontally aligned with ventral margin of eye in larger specimens (100 mm SL or more). Lips smooth or slightly fringed. Premaxillary with three unicuspid teeth gradually decreasing in size from symphyseal tooth. Dentary with four unicuspid teeth decreasing in size postero-laterally.

Scales large and cycloid, with 5 or 6 radii; lateral line extending from supracleithrum to base of caudal-fin median rays, with 34(1), 35(14) or 36*(6) perforated scales. 3(19) or 4*(2) longitudinal series of scales between dorsal-fin origin and lateral line, and 4(21) series of scales between lateral line and pelvic-fin origin. 12*(21) longitudinal series of scales around caudal peduncle. Middorsal line with 11*(21) scales between supraoccipital tip and dorsal-fin origin.

Dorsal fin ii,10*(21); its origin slightly anterior to half of standard length and anterior to pelvic-fin origin. Distal margin of dorsal-fin convex. Adipose fin small, its origin posterior to vertical through origin of anal fin by diameter of one or two scales. Pectoral fin i,14*(15), or i,15(6); its margin slightly convex; its tip when adpressed extending to fourth or fifth scale anterior to pelvic fin. Pelvic fin i,8*(21); its margin concave. Anal fin ii,8*(21), distal margin concave in most specimens; rays not reaching the caudal fin base when adpressed.Caudal fin i,8,9,i*(21); fin distinctly forked with approximately symmetrical lobes.

Coloration: In alcohol-preserved specimens, body ground coloration brown to yellow, distinctly countershaded. Three large rounded to oval dark-brown blotches midlateral on trunk, larger than orbit. Anteriormost blotch below dorsal-fin base; median one dorsal to anal-fin origin; and posterior one on posterior half of caudal peduncle (posterior one always less conspicuous than anterior two, and sometimes completely confluent with last dark transversal bar). Trunk with eight to 14 dark transversal bars on dorsum extending ventrally below lateral line; bars much less conspicuous than midlateral blotches; bars fragmented in some specimens (especially on specimens larger than 80 mm SL) forming inconspicuous blotches. Small specimens (up to 60 mm SL) with eight dark transversal bars on trunk, first one not extending past lateral line scale series. Head distinctly countershaded; upper lip dark. Fins hyaline or uniformly tan except for adipose fin with dark distal margin.

Distribution: Leporinus inexpectatus is known from the entire upper Paraná river basin ( Fig. 2 View Figure 2 ), occurring in the main channel of large rivers such as the Paranapanema and the Tietê rivers, and also in smaller tributaries, in the São Paulo, Paraná, and Minas Gerais states of Brazil. The species was also sampled in the Acaray river, a Paraná-riv- er tributary, a few kilometers below the Itaipu dam, and from tributaries of the Itaipu reservoir in Paraguay ( Géry et al., 1987).

Conservation status: Given the large distribution of the species encompassing almost the entire upper Paraná basin, its relatively common occurrence in fish collections and inventories, and its presence on smaller tributaries of large rivers, the species is herein recommended to be considered as Least Concern, following the IUCN Criteria.

Etymology: The specific name inexpectatus is a Latinized adjective in allusion to the surprising previous inclusion of this species in the type series of Leporinus paranensis , and the fact that it was undescribed, even though it occurs in one of the most sampled area in South America, the upper Paraná basin.