Salminus franciscanus, Lima & Britski, 2007

Lima, Flávio C. T. & Britski, Heraldo A., 2007, Salminus franciscanus, a new species from the rio São Francisco basin, Brazil (Ostariophysi: Characiformes: Characidae), Neotropical Ichthyology 5 (3), pp. 237-244 : 238-241

Salminus franciscanus , new species

Figs. 1-3

Salminus cuvieri (not Valenciennes): Valenciennes, 1850: 62 (in part; “Rio San Francisco”); Lütken, 1875a: 142 (popular name; rio São Francisco and rio Cipó); Lütken, 1875b: 227- 232 (rio das Velhas; rio São Francisco); Steindachner, 1880: 82-83 (rio das Velhas; rio San Francisco); Lütken, 2001: 116- 121 (rio São Francisco and rio das Velhas, Minas Gerais).

Salminus brevidens (not Cuvier): Müller & Troschel, 1844: 91 (“Brasilia”; doubtful identification); Müller & Troschel, 1845: 16, pl. 8, fig. 3 (teeth) (idem); Günther, 1864: 350 (“Cipó River”); Eigenmann, 1916: 91 (Joazeiro; Penedo; Cidade do Barra (= Barra)); Moraes & Schubart, 1955: 11 (rio São Francisco, distribution).

Salminus brasiliensis (not Cuvier): Britski et al., 1984: 52, fig. 49 (Minas Gerais, Três Marias); Petrere Jr, 1989: 11 (rio São Francisco, Três Marias; fisheries); Sato & Godinho, 1999: 406, 410 (rio São Francisco, Minas Gerais; ecology, size, migrations, eggs and larvae); Alves & Pompeu, 2001: 183 (Minas Gerais, rio das Velhas); Nakatani et al., 2001: 105- 109, figs. 23-24 (egg and larvae development); Santos & Godinho, 2002: 163-171 (early ontogeny, larvae morphology and behaviour); Sato & Godinho, 2003:204,208, 210, 215-216 (rio São Francisco, Minas Gerais; migrations, fisheries).

Salminus sp.: Géry & Lauzanne, 1990: 120-123, fig. 5 (rio São Francisco; taxonomic discussion, diagnosis); Pompeu & Godinho, 2006: 430 (Minas Gerais, rio São Francisco, Itacarambi, occurrence in floodplain lagoons).

Holotype. MZUSP 89625 (324.0 mm SL), Brazil, Minas Gerais, Pedro Leopoldo, stream tributary to rio das Velhas, at Igreja Quebrada, near Jaguara (19°27’S, 43°57’W); Exp. MZUSP / USNM / UFSCAR, 19 Jul 1994.

Paratypes: Brazil, rio São Francisco basin , Minas Gerais: MZUSP 19926 (2, 192.0-247.0 mm SL), rio São Francisco, Três Marias ; CODEVASF, 1978 . MZUSP 19524 (2, 125.0- 134.3 mm SL), rio São Francisco, Três Marias ; M.Tozzi da Silva, 1964 . MZUSP 51517 (3, 169.0- 200.4 mm SL), Fortuna de Minas, rio Paraopeba, lagoa Massaracá , 19°34’S, 44°34’W; C.B.M. Alves and team, 19 Mar 1996 . MZUSP 73808 (1, 230.0 mm SL), Lassance , rio das Velhas, at the crossing of the ferry-boat, 17°54’45'’S, 44°34’20'’W; C.B.M. Alves & P.S. Pompeu, 28 Jun 2000 . MZUSP 73833 (1, 310.0 mm SL), Santo Hipólito / Corinto, rio das Velhas, Nossa Senhora da Glória , village of Caquende , 18°24’56'’S, 44°11’20'’W; C. B. M. Alves & P. S. Pompeu, 18 Jun 1999 . MZUSP 47244 (6, 189.4-324.0 mm SL), Pedro Leopoldo , stream tributary to rio das Velhas, at Igreja Quebrada, near Jaguara; Exp . MZUSP / USNM /UFSCAR, 19 Jul 1994 . MZUSP 39727 (16, 228.0-302.0 mm SL), rio São Francisco and tributaries, UHE Formoso region (downstream from Pirapora ); Y. Sato, Nov 1987 to Aug 1988. MZUSP 38999 (1, 451.0 mm SL) ; MZUSP 39000 (1, 773.0 mm SL), same data as previous . MZUSP 39691 (9, 172.5-253.0 mm SL), rio São Francisco, Pontal do Abaeté ; Y. Sato (UHE Formoso project), 22 Jul 1988 . MZUSP 39683 (1, 200.7 mm SL), córrego Espraiado, rio Abaeté ; Y. Sato (UHE Formoso project), 21 Jul 1988 . MZUSP 42071 (3, 185.8-361.0 mm SL), lagoa Mocambinho, rio São Francisco right margin, Manga; J. C. Oliveira & O . T. Oyakawa , 22 Jul 1990 . MNRJ 25995 (3, 158.2-353.0 mm SL), Manga, stream and lagoon at Mocambinho, rio São Francisco right margin; J. C. Oliveira & O . T. Oyakawa , 17-22 Sep 1990 . MNRJ 17376 (1, 217.6 mm SL), Manga, lagoa de Mocambinho ( rio São Francisco right magin), Mocambinho; J. C. Oliveira & M. S. Menezes, 8 Mar 1990 . MNRJ 16137 (1, 167.9 mm SL), Manga, rio São Francisco, ilha do Caju (right margin), downstream from Mocambinho ; D. F. Moraes Jr. & J. C. Oliveira, 21 Aug 1990 . MNRJ 17373 (1, 143.1 mm SL), Manga, riacho Mocambinho ( rio São Francisco right margin), Mocambinho; J. C. Oliveira, M. S. Menezes & E. Carelis, 6 Apr 1990 . MNRJ 17387 (2, 167.2- 219.1 mm SL), Manga, artificial channel ( rio São Francisco right margin), Mocambinho; J. C. Oliveira & M. S. Menezes, 11 Mar 1990 . MNRJ 17408 (3, 246.7- 265.4 mm SL), Manga, rio São Francisco at Mocambinho (artificial channel, right margin); J. C. Oliveira & M. S. Menezes, 3 Apr 1990 . MNRJ 17391 (1, 288.2 mm SL), Manga, artificial channel ( rio São Francisco , right margin), Mocambinho; J. C. Oliveira & M. S. Menezes, 5 Apr 1990 . MNRJ 16364 (1, 100.8 mm SL), Manga, artificial channel, rio São Francisco (right margin), Mocambinho; J. C. Oliveira, 11 Dec 1989 . MZUSP 54754 (1, 205.0 mm SL), Januária, rio Pandeiros, 48 km from Januária , 15°30’48'’S, 44°45’12'’W; S. A. Schafer et al., 14 Jul 1993 . BMNH 1924.6 .2.2 (1, 323.0 mm SL), Jaguara, rio das Velhas (about 32 miles north of Belo Horizonte ); Chalmers . BMNH 1924.6 .16.6 (1, 755.0 mm SL), same data as previous . Bahia: MZUSP 28797 (17, 165.9-237.0 mm SL), rio das Fêmeas, near Barreiras; M. A. Cestarolli & J. Camargo, 2-6 May 1985 . MZUSP 79859 (5, 2 cs, 98.9-156.0 mm SL), Barra, rio Grande, tributary of rio São Francisco , Cabeça de Touro beach, 11°6’8'’S, 43°9’26'’W; O . T. Oyakawa, A. Akama & J. C. Nolasco, 10 Apr 2001 . UFPB 2571 (1, 226.0 mm SL), Santa Maria da Vitória, rio Corrente ; G. Gomes Filho, Oct 1992 . MZUSP 20443 (1, 297.0 mm SL), rio São Francisco , downstream Sobradinho ; R. dos Santos , 13 Oct 1976 .

Not types: Brazil, rio São Francisco basin, Minas Gerais: MCP 14123 (4, 261.1- 273.1 mm SL), Três Marias, rio São Francisco between Três Marias and Pirapora. MZUSP 1534 (3, 118.3-262.0 mm SL), rio São Francisco , Pirapora. MZUSP 1954 (2, 176.5-211.0 mm SL), Pirapora, stream tributary to rio São Francisco. MNRJ 21841 (4, 31.7-45.2 mm SL), Minas Gerais, Pirapora. MZUSP 89512 (1, skel., 225.0 mm SL), rio São Francisco. Bahia: NMW 81898 (1, 259.0 mm SL), “Rio das Velhas” (no specific locality). NMW 56860 (2, 140.3-144.0 mm SL), Santa Rita; Bras. Exped., January 1904. NMW 56862 (3, 121.0-134.0 mm SL), same data as previous. NMW 56858 (2, 145.0-146.4), Barra . Brazil, no specific locality: NMW 56867 (2, one measured, 209.0 mm SL), “ Rio São Francisco ”. MNHN A.8556 (452.1 mm SL, stuffed), “ Rio San Francisco ” .

Diagnosis. Salminus franciscanus can be diagnosed from all Salminus species, except S. brasiliensis , by the presence of a second dentary tooth in the outer tooth series that is considerably larger than the remaining teeth (vs. second dentary teeth only slightly larger than remaining teeth in S. affinis and S. hilarii ). Salminus franciscanus can be additionally diagnosed from S. affinis by the absence of the dark post-orbital stripe that is characteristic from the latter species. Salminus franciscanus can be diagnosed from S. brasiliensis in possessing much lower scale counts, i.e., lateral line (68-82, modally 77 scales, vs. vs. 79-102, modally 96), horizontal between dorsal-fin origin and lateral line (11-14, modally 12, vs. 14-18, modally 16) and horizontal between lateral line and pelvic-fin insertion (6-8, modally 6, vs. 6-9, modally 8). In spite of the great overlap, Salminus franciscanus has generally more lateral line (68-82, modally 77 scales, vs. 54-72, modally 65-66), horizontal between dorsal-fin origin and lateral line (11-14, modally 12, vs. 9-12, modally 10), and horizontal between lateral line and pelvic-fin insertion (6-8, modally 6, vs. 4-7, modally 5), scales, when compared to the sympatric S. hilarii . In life, Salminus franciscanus can also be distinguished from S. hilarii by the presence of golden coloration mainly over the facial bones and pectoral girdle (vs. facial bones and pectoral girdle silvery). See under “Remarks”, below, for more details on the diagnosis of Salminus franciscanus regarding its congeners.

Description. Morphometric data presented in Table 1. Largesized species, larger specimen examined reaching 755 mm SL. Body relatively slender, moderately deeper in specimens larger than 360 mm SL. Greatest body depth at dorsal-fin origin. Dorsal profile of head and body slightly convex from margin of upper lip to vertical through anterior nostril, straight to slightly concave from latter point to supraoccipital spine, moderately convex from latter point to dorsal-fin origin, then straigth along dorsal-fin base and slightly convex to straight from posterior of dorsal-fin base to adipose-fin origin. Dorsal profile of caudal peduncle slightly concave. Ventral profile of head and body slightly convex from lower lip to pelvic-fin insertion, straight to slightly convex from latter point to analfin origin, and approximatelly straight along anal-fin base. Ventral profile of caudal peduncle slightly concave.

Head profile acute anteriorly. Mouth terminal. Maxilla extending posteriorly little beyond vertical through posterior margin of eye in specimens greater than 165 mm SL, not reaching latter point in smaller specimens. Adipose eyelid relatively well developed, covering anterior portion of eye. Premaxilla with two series of teeth. Teeth of outer series considerably larger that those of inner series other than for second tooth of inner series. Outer series with 4-8 teeth approximatelly equal in size; teeth with distinct, elongate basal portion (shaft), and apical portion (crown). Crown triangular, with angles possibly constituting poorly differentiated cusps. Inner tooth series with 7-15 teeth. Symphyseal tooth relatively large, second tooth slightly smaller, third and subsequent teeth considerably smaller. Teeth of inner series of form comparable to those from outer series, except for proportionally shorter shafts and being more massive overall. Middle portion of ventral margin of maxilla slightly concave. Maxilla with 23-37 teeth of form similar to those of outer series in premaxilla, but slightly smaller and decreasing very gradually in size posteriormost with less developed crowns. Last teeth conical. Dentary with 16 to 29 teeth on primary series; teeth similar in form to those of outer series in premaxilla outer series, and other than first through third teeth slightly smaller than those on premaxilla. Second teeth on primary series of dentary considerably larger than other teeth in that series in specimens of all sizes. Third through last teeth progressively decreasing in size with less developed crowns. Teeth of outer series of dentary, outer series on premaxilla, and teeth on maxilla with crowns slightly recurved lingually. Inner tooth series on dentary with 53-58 conical teeth arranged in continuous series from symphysis to terminus of inner rim of replacement teeth trench. Teeth in inner series oriented at right angle to teeth of primary series with apices directed lingually.

Scales cycloid. Lateral line complete, extending from supracleithrum to caudal-fin base. Lateral-line scales 68 (1), 70 (1), 71 (2), 72 (6), 73 (10), 74 (7), 75 (12), 76* (13), 77 (16), 78 (9), 79 (3), 80 (3), or 82 (1). Laterosensory tubes simple and straight or deflected downwards. Horizontal scales series between dorsal-fin origin and lateral line 11 (11), 12* (57), 13 (13), or 14 (1). Horizontal scale series between lateral line and pelvic-fin insertion 6* (42), 7 (34), or 8 (5). Circumpeduncular scales 21 (4), 22 (11), 23* (35), 24 (30), or 25 (3).

Dorsal-fin rays ii,9. Dorsal-fin origin approximatelly midway between snout and hypural joint. First dorsal-fin pterygiophore inserting behind neural spine of 14th (2), 15th (4), or 16th (1) vertebrae. Anal-fin rays iii (not including first, small unbranched ray discernible only on cs specimens), 23 (8), 24 (12), 25 (30), 26* (27), 27 (4), or 28 (1). First anal-fin pterygiophore inserting behind haemal spine of 26th (1), 27th (3), or 28th (4) vertebrae. Last unbranched ray and first and second anal-fin branched rays longer; third to ninth rays gradually shortening with remaining rays approximatelly equal in size. Pectoral fin rays i,12 (1), 13* (19), 14 (50), 15 (12), or 16 (1). Pelvic-fin rays i,7. Principal caudal fin rays 10/9. Anal fin with small hooks along last unbranched ray and anterior 15- 19 branched rays (MZUSP 39727, 235.0-283.0 mm SL, and MZUSP 20443, 297.0 mm SL). Hooks limited to posterior branch of rays. Pelvic fins with hooks on branched rays 1-6 of same specimens and limited to posterior branch. Scales sheath composed of two horizontal series covering basal portion of anal-fin rays. Caudal fin moderately forked to slightly emarginated. Laterosensory tube extending over interradial membrane between upper and lower caudal-fin lobes to caudal-fin terminus. Laterosensory tube on caudal fin with dorsally and ventrally oriented side branches across its length. Central caudal-fin extension well-developed, extending beyond primary margin of fin for distance equal to onethird to one-half beyond of length of median caudal-fin rays.

Branchiostegal rays 4. First gill arch with 14 (1), 15 (2), 16 (1), or 17 (1) lower gill rakers, 13 (3), 14 (1), or 15 (1) upper gill rakers and 1 at angle. Vertebrae 50 (2), 51 (2), or 52 (4). Supraneurals 11 (4) or 12 (3).

Coloration in alcohol. Overall coloration from specimens still retaining guanine plumbeous-gray, with brownish hue dorsally. Top of head (including supraorbital, infraorbitals 4 and 5, and dorsal portion of opercle), snout and anterior portion of maxilla brown. Remaining infraorbitals and ventral portion of opercle silvery. Lateral portions of body lightly colored, with silvery hue and dark-grey dorsally. Dark humeral spot present, but relatively inconspicuous. Spot horizontally ovoid, formed by pigmentation subjacent to scales, and situated above second and third lateral line scales. Dark, straight longitudinal stripes formed by dark chromatophores concentrated on mid to distal portions of each scale extending along trunk. Stripes more discernible dorsally. Caudal peduncle with broad median stripe, originating 3-5 scales from hypural joint and continuing posteriorly over 3-4 central principal caudalfin rays. Dorsal and anal fins with few chromatophores forming ill-defined dark stripes across interradials membranes. Pectoral, pelvic, and adipose fins clear, with few, scattered dark chromatophores. Specimens lacking guanine as result of long storage in formalin brown overall, without silvery hue on lateral portions of body, infraorbitals or opercle.

Life coloration. Description based on photographs of two freshly collected specimens from rio Paraopeba (not preserved; Fig. 3 ), one specimen from rio Urucuia (not preserved), and one specimen from rio São Francisco (MZUSP 89512). Dorsal portion of body and head dark gray; lateral portions of body lightly pigmented with silvery hue. Infraorbitals, opercular series, and pectoral girdle golden. Fins, including adipose fin, yellow-orangish but with reddish margin on caudal fin.

Sexual dimorphism. The presence of hooks on pelvic and anal fins (less often other fins) is considered to be a dimorphic sexual character, present in mature males of most Characidae (Malabarba & Weitzman, 2003) . Anal and pelvic fin hooks were found in several examined specimens of Salminus franciscanus (MZUSP 39727, 7, 235.0-283.0 mm SL, and MZUSP 20443, 297.0 mm SL). Two of these specimens (MZUSP 39727, 260 and 283 mm SL) were found to be males on dissection. Salminus franciscanus females are reported to grow larger than males of the species (Sato & Godinho, 2003).

Common names: Brazil: dourado (e.g., Lütken, 1875b, 2001; Britski et al., 1984; Alves & Pompeu, 2001).

Distribution. Salminus franciscanus is endemic from the rio São Francisco basin, Brazil ( Fig. 4 ).

Biology, ecology, and fisheries. There is little published information about the general biology and ecology of Salminus franciscanus , when compared to its much better known congener S. brasiliensis , an unfortunate fact since the species has been recognized as distinct (even if under misapplied names) since late XIX century. Salminus franciscanus is reported to reach one meter in total length and to weigh up to 30 kg (Sato & Godinho, 1999, 2003; as S. brasiliensis ; C.B.M. Alves, pers. comm.), being, consequently, one of the largest known Characiformes . It is a piscivore, which undertake reproductive migrations during the rainy season (Sato & Godinho, 1999, 2003; as S. brasiliensis ). Juveniles (<600 g) were collected in marginal lagoons of the rio São Francisco, which indicates that those are recruiting habitats for the species (Sato & Godinho, 2003; as S. brasiliensis ). Salminus franciscanus is one of the main targets of the commercial and amateur fisheries in the middle rio São Francisco basin ( Petrere, 1989; Sato & Godinho, 2003; as S. brasiliensis ). The early larval development of the species was described by Santos & Godinho (2002; as S. brasiliensis ).

Etymology. Franciscanus, after rio São Francisco, the river basin from which the species is endemic.

Figures

Fig. 1. Salminus franciscanus, holotype, MZUSP 89625, 324.0 mm SL; Brazil, Minas Gerais, stream tributary to rio das Velhas.

Fig. 2. Salminus franciscanus, paratype, MZUSP 38999, 451.0 mm SL; Brazil, Minas Gerais, rio São Francisco.

Fig. 3. Salminus franciscanus (not preserved), SL unrecorded, Brazil, Minas Gerais, rio Paraopeba, UTE Igarapé, 19°57’S, 44°16’W; coloration in life. Photo by Carlos B.M. Alves.

Fig. 4. Map of eastern and northeastern Brazil showing the distribution of Salminus franciscanus.A square indicates the type locality.