Psalidodon, Eigenmann, 1911

Queiroz, Victor de, Silva, Priscilla Caroline, Malabarba, Maria Claudia, Weigt, Lee, Dergam, Jorge Abdala & Malabarba, Luiz R., 2023, DNA extracted from museum specimens of the 19 century provides a taxonomic resolution on the identity of the characid fish Psalidodon jequitinhonhae (Ostariophysi: Characiformes), Neotropical Ichthyology (e 230094) 21 (4), pp. 1-21 : 9-14

Psalidodon jequitinhonhae (Steindachner, 1877)

( Figs. 2 , 4–6 )

Tetragonopterus rutilus var. Jequitinhonhae Steindachner, 1877:693 [135], plate 2 (fig. 3). On p. 135 of separate. Name given in caption on p. 693 for the plate.

Tetragonopterus rutilus jequitinhonhae . —Eigenmann, Eigenmann, 1891:52 (checklist).

Astyanax fasciatus jequitinhonhae . —Eigenmann, 1910:433 (checklist). —Eigenmann, 1921:304 (description, Jequitinhonha and Arassuahy [Araçuaí] rivers, Jequitinhonha River basin; plate 50, fig. 3 – photo). — Fowler, 1948:48 (checklist, fig. 38 – drawing based on Eigenmann’s photo; distribution Bahia). —Triques et al., 2003:149 (listed and compared to Astyanax turmalinensis Triques, Vono & Caiafa, 2003 ).

Astyanax fasciatus . —Lima et al., 2003:109 (listed as provisional synonym).

Astyanax jequitinhonhae . —Melo, 2005 (unpublished thesis, new combination not available according to the ICZN; listed as a valid species and not as a subspecies).

Astyanax cf. jequitinhonhae . —Rossini et al., 2016:4 (barcode segment of the 5’ region of the mitochondrial COI gene of four specimens from Itaobim, MG, in the Jequitinhonha River, compared to other species of Astyanax ).

Psalidodon jequitinhonhae . —Terán et al., 2020:10 (phylogenetic relationships).

Astyanax aff. jequitinhonhae . —Silva-Santos et al., 2023:7 (molecular comparison to Astyanax species from the upper Paraguaçu River basin), tab. S2 (sequences downloaded from BOLD system; same sequences of Rossini et al., 2016).

Diagnosis. The presence of a single humeral spot diagnoses P. jequitinhonhae from P. bifasciatus (Garavello & Sampaio, 2010) , P. bockmanni (Vari & Castro, 2007) , P. chico (Casciotta & Almirón, 2004) , P. dissensus (Lucena & Thofehrn, 2013) , P. eigenmanniorum (Cope, 1894) , P. gymnodontus Eigenmann, 1911 , P. leonidas (Azpelicueta, Casciotta & Almirón, 2002) , P. ojiara (Azpelicueta & Garcia, 2000) , P. pampa (Casciotta, Almirón & Azpelicueta, 2005) , P. powelli (Terán, Butí & Mirande, 2017) , P. pynandi (Casciotta, Almirón, Bechara, Roux & Ruíz Díaz, 2003) , P. rivularis (Lütken, 1875) , P. troya (Azpelicueta, Casciotta & Almirón, 2002) , P. xavante (Garutti & Venere, 2009) , and P. xiru (Lucena, Castro & Bertaco, 2013) that present two humeral spots. The number of branched anal-fin rays, 21–25, differs P. jequitinhonhae from P. pellegrini (Eigenmann, 1907) , P. erythropterus (Holmberg, 1891) , P. correntinus (Holmberg, 1891) , and P. schubarti (Britski, 1964) that have 27 or more branched anal-fin rays, and from P. pampa , P. paranae (Eigenmann, 1914) , and P. rioparanaibanus Alves, Oliveira, Pasa & Kavalco, 2020 that have up to 18 branched anal-fin rays. The number of perforated lateral line scales, 34– 37, differs P. jequitinhonhae from P. erythropterus , P. pellegrini , P. gymnogenys (Eigenmann, 1911) , P. rutilus , and P. correntinus that have 39 or more perforated lateral line scales and from Psalidodon parahybae (Eigenmann, 1908) that has 37–40 perforated scales. The presence of 5 or 6 scales between the lateral line and dorsal fin and of 4 or 5 scales between lateral line and pelvic fin distinguish P. jequitinhonhae from P. correntinus , P. hermosus (Miquelarena, Protogino & López, 2005) , P. marionae (Eigenmann, 1911) , and Psalidodon endy (Mirande, Aguilera & Azpelicueta, 2006) that presents 7 or 8 scales between the lateral line and dorsal fin and of 6 or 7 scales between lateral line and pelvic fin. The presence of four anterior large penta- do heptacupspidate teeth, followed by an intermediary size tricuspidate tooth and eighth smaller tricuspid or conical teeth differs P. jequitinhonhae from P. ita (Almirón, Azpelicueta & Casciotta, 2002) and P. puka (Mirande, Aguilera & Azpelicueta, 2007) that shows a series of 7 or more teeth gradually decreasing in size posteriorly. The light pigmentation of body scales distinguishes P. jequitinhonhae from P. tumbayaensis (Miquelarena & Menni, 2005) that shows a distinctive reticulated color pattern on body scales. The fully pored lateral line series distinguish P. jequitinhonhae from P. anisitsi (Eigenmann, 1907) with 8 to 25 perforated scales. The lack of an elongated dorsal fin in males distinguish P. jequitinhonhae from P. fasciatus .

Description. Morphometric data in Tab. 1. Body compressed and elongated, with highest body depth at vertical through dorsal-fin origin. Dorsal profile of head smoothly convex or nearly straight from upper lip to tip of supraoccipital spine, slightly concave at supraoccipital in some specimens. Dorsal body profile slightly convex from tip of supraoccipital to dorsal-fin base; straight and posteroventrally slanted along dorsal-fin base and slightly convex between dorsal and adipose fins. Ventral profile smoothly convex from anterior tip of dentary to pelvic-fin insertion, and nearly straight from that point to anal-fin origin. Ventral body profile nearly straight along anal-fin base. Caudal peduncle nearly straight along both dorsal and ventral margins.

Head small, head length nearly one-fourth of SL. Snout length smaller than eye diameter. Mouth terminal. Maxilla almost vertically positioned; posteriormost margin positioned nearly in a vertical through anterior border of pupil with mouth closed. Anteroventral border of maxilla convex and posterodorsal border concave. Infraorbital series complete, third infraorbital leaving naked area posteroventrally, not contacting preopercle.

Premaxillary teeth in two rows; outer row with 4(49) teeth with three cusps, with central cusp longer. Inner row with 5(49) teeth; symphyseal tooth asymmetrical, with one or two shorter cusps on medial side near symphysis, followed by one highest cusp and another two or three shorter cusps on lateral side of tooth; second to fourth teeth bearing five to seven cusps, usually five cusps; last tooth abruptly smaller with three to five cusps. Maxilla with 1(49) tooth, rarely 2(4) teeth, with three to five cusps, central cusp highest. Four anteriormost dentary teeth larger, with five cusps (43), rarely seven cusps (3), followed by an intermediary tricuspidate tooth (23) and a series of usually eight smaller tricuspid or conical teeth ( Fig. 5 ).

Dorsal-fin rays ii,9*(70). First unbranched ray approximately one-half length of second unbranched ray. Distal margin of dorsal fin straight. Dorsal-fin origin approximately at middle of standard length (SL) and slightly posterior to vertical through pelvic-fin origin. Adipose fin approximately at vertical through last anal-fin rays insertion. Anal-fin rays iii(44), iv*(34), 21(7), 22(18), 23*(14), 24(17), 25(22). Anal-fin distal border concave; anteriormost branched rays longer forming anterior lobe. Anal-fin origin approximately at vertical through base of last dorsal-fin ray. Pectoral-fin rays i,12(28), 13(23), 14(6). Pectoral-fin tip reaching pelvic-fin insertion in males and not reaching in females. Pelvic-fin rays i,7(72). Pelvic-fin origin anterior to vertical line through dorsal-fin origin. Pelvic-fin tip reaching anal-fin origin in males and not reaching in females. Caudal-fin forked with 19(69) principal rays, lobes similar in size.

Lateral line slightly curved ventrally in abdomen, and then nearly straight through caudal fin; completely pored, with 34(2), 35(8), 36(47), 37*(21) scales. Horizontal scale rows between dorsal-fin origin and lateral line 5(9) or 6*(75). Horizontal scale rows between lateral line and pelvic-fin origin 4(22) or 5*(61). Pre-dorsal scales 10(7), 11(28), 12(29) arranged in regular series. Scale rows around caudal peduncle 12(17), 13(29), 14(19). Scale sheath along anal-fin base formed by eight to fourteen scales in single series and covering base of anteriormost rays.

Supraneurals 5(2), dorsal pterygiophores 11(2), anal pterygiophores 21(1) or 22(1). Total vertebrae 36(1) or 37(1): precaudal vertebrae 15(1) or 16(1) and caudal vertebrae 19(1) or 21(1). Upper branch gill-rakers 9+1(1), lower branch 12(1). First dorsal-fin pterygiophore inserted posterior to neural spine of eighth (1) or nineth (1) vertebra, first anal-fin pterygiophore inserted posterior to haemal spine of 13 th (1) or 14 th (1) vertebra.

Coloration in alcohol. Dorsal and dorsolateral portions of head light gray. Infraorbitals, preopercle and opercle silvery, lacking chromatophores. Dorsal and dorsolateral portion of body light brown, with scattered black chromatophores not forming distinctive marks. Lateral of body with a wide conspicuous silvery lateral band partially covering two or three longitudinal series of scales, located dorsally to lateral line scale series on belly and over lateral line scale series on caudal peduncle. In specimens lacking guanine, the lateral band forms a wide black stripe laterally on body and continuous to black pigmented middle caudal-fin rays. Brownish humeral blotch, small, vertically elongate, two to three scales wide and extending two scales above lateral line. All fins mostly unpigmented, except for the middle caudal fin rays with a conspicuous black stripe ( Fig. 4 ).

Coloration in life. Dorsal and dorsolateral portions of head and body olive brown. Scales above lateral band with scattered black chromatophores not forming distinctive marks. Infraorbitals, preopercle and opercle white silvery, showing sparse black chromatophores in the area posterior to eye. Lateral of body with a wide conspicuous olive green bright longitudinal band partially covering two or three longitudinal series of scales, located dorsally to lateral line scale series on belly and bordering lateral line scale series on caudal peduncle. A black horizontally elongated blotch on caudal peduncle, distant from upper and lower borders of caudal peduncle, continuing on caudal-fin base and middle caudal-fin rays. Humeral blotch black, in two longitudinal series of scales immediately above the lateral line, two scales wide. Lateral of body below lateral band white. Pectoral, pelvic and anal fins mostly hyalines. Dorsal and adipose fins beige. Caudal fin yellowish proximally and light reddish distally, with a conspicuous black stripe on middle caudal fin rays ( Fig. 6 ).

Sexual dimorphism. Bony hooks were observed on pelvic-, pectoral- and anal-fin rays, only in males. In the anal fin, the bony hooks are elongate, one per segment of each lepidotrichia, more numerous from the last unbranched ray to the eighth or ninth branched rays, and smaller and less numerous on the branched portion of remaining anal-fin rays, with the number decreasing posteriorly; the hooks are nearly straight with a rounded base and distal end directed laterodorsally nearly parallel to ray axis. On the pelvic fin, the bony hooks are elongated, one per segment and positioned ventrally; the hooks are nearly straight with a rounded base and distal end directed to the fin ray base end nearly parallel to ray axis. Pectoral fin with fewer, smaller and short bony hooks near the tip of fin rays (MZUEL 10809).

Geographical distribution. Psalidodon jequitinhonhae is currently known from the Jequitinhonha and Pardo river basins, two coastal drainages, in the States of Minas Gerais and Bahia, southeastern and northeastern Brazil ( Fig. 7 ) .

Conservation status. The Extent of Occurrence (EOO) and Area of Occupancy (AOO), applying a 2 km ² area for each locality of Psalidodon jequitinhonhae were estimated, according to the collection sites of the analyzed specimens. Psalidodon jequitinhonhae has, EOO to 8,274.050 km ² and AOO of 40.000 km ². These values are beyond the minimum limits defined by the International Union for Conservation of Nature (IUCN) for threatened categories, under the criteria B (B1: EOO <5,000 km ²; B2: AOO <500 km ²). Thereby, P. jequitinhonhae can be classified as Least Concern (LC), according to IUCN categories and criteria (IUCN Standards and Petitions Subcommittee, 2022).

Material examined. All from Brazil. Psalidodon jequitinhonhae : Lectotype of Tetragonopterus rutilus jequitinhonhae by present designation ( Fig. 2 ): NMW 57760:2, 67.5 mm SL, rio Jequitinhonha , 1874. Paralectotypes: NMW 57759 , 5 , 54.3–68.4 mm SL. NMW 57760 , 2 , 65.2–74.1 mm SL. NMW 57761 , 6 , 66.2–75.6 mm SL, same data as the lectotype. Minas Gerais State, Jequitinhonha River basin. LBP 8311 , 14 , 35.6 – 74.4 mm SL, 2 c&s 47.4–55.9 mm SL of 43, rio Jequitinhonha , Itaobim, 16°30’36”S 41°20’02”W, 15 May 2009, C. Oliveira, G. J. C. Silva, F. F. Roxo & T. N. A. Pereira. MZUEL 10809 , 6 of 12 measured (ms), 70.3–78.1 mm SL, rio Fanado , tributary of rio Araçuaí, Capelinha, 17°38’01”S 42°26’48”W, 21 Jun 2014, F. Andrade-Neto, T . Barroso & I. G. Prado. MZUEL 10810, 3 of 7 ms, 30.5–60.7 mm SL, córrego Varão, tributary of rio Araçuaí , Capelinha, 17°32’57”S 42°22’31”W, 1 July 2014, F. AndradeNeto, T. Barroso & I. G. Prado. MZUEL 10812 , 2 of 9 ms, 42.8–76.4 mm SL, rio Fanado , tributary of rio Araçuaí, Capelinha, 17°32’57”S 42°22’31”W, 21 Jun 2014 , F. Andrade-Neto, T. Barroso & I. G. Prado. MZUEL 12166, 4 of 10 ms, 72.5–77.5 mm SL, tributary of rio Araçuaí, Turmalina, 17°54’07”S 42°33’14”W, 21 Jun 2014, F. Andrade-Neto, T. Barroso & I. G. Prado. MZUEL 16425, 13, rio Fanado, tributary of rio Araçuaí, Barragem das Almas, Minas Novas, 17°14’16.1”S 42°35’25.9”W, 5 Jul 2016, J. Birindelli, F. Jerep, E. Santana & R. Nascimento. MZUEL 17997, 3 of 9 ms, 75.7–82.7 mm SL, rio Fanado, tributary of rio Araçuaí, on the bridge to Turmalina, Minas Novas, 17°13’13”S 42°35’47”W, 5 Jul 2016, J. Birindelli, F. Jerep, E. Santana & R. Nascimento. MZUEL 7197, 3 of 4 ms, 68.2–74.0 mm SL, rio Soledade, Carbonita, 17°31’29”S 43°01’59”W, 14 Sep 2012, F. Andrade-Neto, T. Barroso & I. G. Prado. MZUEL 7217, 3 of 14 ms, 27.2–41.6 mm SL, rio Jequitinhonha, road between Itamarandiba and Senador Modestino, Itamarandiba, 17°54’13”S 43°01’30”W, 16 Sep 2012, F. Andrade-Neto, T. Barroso & I. G. Prado. MZUEL 7223, 4 of 24 ms, 29.1–31.9 mm SL, rio Jequitinhonha, road between Itamarandiba and Senador Modestino, Itamarandiba, 17°53’41”S 43°04’25”W, 16 Sep 2012, F. Andrade-Neto, T. Barroso & I. G. Prado. UFRGS 29499 15 ms, 42.0– 62.1 mm SL (formerly MZUFV 3167), Calhauzinho Dam, rio Araçuaí, Araçuaí, 16°57’43”S 42°0’8”W, 19 Dez 2001, A. A. Oliveira. MZUFV 3582, 3, 76.4–113.1 mm SL, rio Setúbal [precise locality not specified], rio Araçuaí basin, J. A. Dergam & A. A. Oliveira. MZUFV 4193, 6 ms, 44.96–84.13 mm SL, rio Jequitinhonha [precise locality not specified], 17 Aug 2007, F. P. Rezende. Pardo River basin: MZUFV 3422, 6 of 14 ms, 70.7–80.9 mm SL, rio Pardo [precise locality not specified], 17 Mar 2004, A. A. Oliveira. MCP 17936, 8 of 33 ms, 47.5–62.3 mm SL, rio Pardo on the road bridge from Itambé to Tomba, about 3 km south of Itambé, Itambé, Bahia, 15°16’44”S 40°37’35’’W, 22 Jan 1995, R. E. Reis, J. F. P. da Silva, W. G. Saul & E. H. L. Pereira. MCP 40142, 6 of 10 ms, 46.7–74.1 mm SL, rio São João , tributary of rio Pardo, São João do Paraíso, Minas Gerais, 15°09’50”S 42°09’45”W, 26 Apr 2006, J. Dergam & A. A. Oliveira.

Figures

FIGURE 2 | Lectotype of Tetragonopterus rutilus jequitinhonhae, NMW 57760:2, 67.52 mm SL.

FIGURE 4 | Psalidodon jequitinhonhae. Specimens from Jequitinhonha River, Itaobim Municipality, Minas Gerais State, Brazil, 16°30’36”S 41°20’02”W. LBP 8311, male, 57.7 mm SL, female, 57.4 mm SL.

FIGURE 5 | Psalidodon jequitinhonhae, LBP 8311, 55.9 mm SL. To the left: lateral view of maxillary, premaxillary and dentary teeth. To the right: medial view of premaxillary and dentary teeth.

FIGURE 6 | Psalidodon jequitinhonhae. Two live specimens from Fanado River, tributary of Araçuaí River, Barragem das Almas, Minas Novas Municipality, Minas Gerais State, Brazil, Jequitinhonha River basin, 17°14’16.1”S 42°35’25.9”W. MZUEL 16425, not measured. Photo: José L. O. Birindelli.

FIGURE 7 | Distribution map of Psalidodon jequitinhonhae, encompassing its occurrence in the Jequitinhonha and Pardo river basins, Minas Gerais and Bahia States, Brazil.