Hoplias brasiliensis ( Spix, 1829 )

Oyakawa, Osvaldo T. & Mattox, George M. T., 2009, Revision of the Neotropical trahiras of the Hoplias lacerdae species-group (Ostariophysi: Characiformes: Erythrinidae) with descriptions of two new species, Neotropical Ichthyology 7 (2), pp. 117-140 : 122-125

Hoplias brasiliensis ( Spix, 1829)

Fig. 4

Erythrinus brasiliensis Spix in Spix & Agassiz, 1829: 45, pl. 20 [original description, type locality: Paraguaçú, Bahia State, Brazil]. - Günther, 1864: 281 [species list as synonym of Macrodon trahira ]. - Lütken, 2001: 78 [footnote, synonym of Macrodon trahira ]. - Eigenmann & Eigenmann, 1889: 103 [species list as synonym of Macrodon malabaricus ]. - Eigenmann, 1910: 448 [species list as synonym of Hoplias malabaricus ]. - Eigenmann, 1912: 416 [species list as synonym of Hoplias malabaricus ]. - Fowler, 1950: 364 [species list as synonym of Hoplias malabaricus malabaricus ]. - Godoy, 1975: 405 [as synonym of Hoplias malabaricus malabaricus ].

Macrodon brasiliensis : - Müller, 1842: 309 [species list]. - Müller, 1843: 316 [species list]. -Müller & Troschel, 1844: 82 [species list]. -Müller & Troschel, 1845: 6 [species list]. - Godoy, 1975: 405 [as synonym of Hoplias malabaricus malabaricus ].

Hoplias brasiliensis : - Oyakawa, 2003: 239 [species list, distribution]. -Oyakawa & Netto-Ferreira, 2007: 63 [species list, distribution]. - Menezes et al., 2007: 152 [type-locality, distribution].

Neotype. BRAZIL. Bahia State. MZUSP 45483 , 1, 162.9 mm SL, rio Paraguaçú near Iaçú , 25 Jul 1988, R. Castro, S. Jewett & H. Santos. [designated herein].

Material examined. BRAZIL. Bahia State. Paraguaçú basin: MZUSP 40171, 10, 39.3-122.8 mm SL; MZUSP 40172, 7, 41.3- 94.9 mm SL, rio Paraguaçú near Iaçú; MZUSP 47939, 11, 23.7-66.2 mm SL; MZUSP 49234, 12, 23.1-65.1 mm SL, rio do Una, rio Paraguaçú drainage, Itaetê; MZUSP 40173, 1, 114.5 mm SL, lagoa Charca Natividade, floodplain of rio Paraguaçú, Iaçú; MZUSP 86123, 1, 112.5 mm SL, rio do Una, Rumo village, Itaetê; MZUSP 87684, 2, 83.9-132.2 mm SL, rio do Una, Fazenda Nova Iguaçú, Itaetê. Bahia, rio de Contas basin: MZUSP 40174, 1, 82.7 mm SL, rio Gongoji, tributary to rio de Contas, Fazenda Itamarati, 5 km from Dário Meira; MZUSP 41500, 2, 32.1-35.1 mm SL; MZUSP 39797, 7, 19.2-54.0 mm SL, rio de Contas, Ipiaú. Bahia. Pardo basin: MZUSP 40170, 2, 193.9- 205.7 mm SL, rio Pardo, Fazenda Hermógenes, 5 km upstream from ferry-crossing, Itapetininga. Minas Gerais State. Jequitinhonha basin: MZUSP 40269, 7, 95.5- 273.4 mm SL, rio Jequitinhonha near Araçuaí, Vila Itira; MZUSP 40270, 7, 38.7-137.0 mm SL, rio Jequitinhonha, Ilha Almenara, Curiango; MZUSP 74032, 3, 27.8-39.4 mm SL, marginal lagoon of rio Jequitinhonha, km 205 of Salto da Divisa-Jacinto road.

Diagnosis. The number of pores of the laterosensory canal along the ventral surface of the dentary distinguished Hoplias brasiliensis from H. lacerdae (4-6 vs. 6-8 respectively). It can be distinguished from H. intermedius by the number of the scales along the lateral line (38-43 vs. 42-46 respectively). The anterior profile of head that is angular in lateral view distinguished H. brasiliensis from H. australis , H. curupira and H. lacerdae , which have the anterior profile of head rounded. It can be further distinguished from H. curupira by having light brown ground coloration of the head and body.

Description. Morphometric data presented in Table 4. Body cylindrical, deeper than wide. Greatest body depth at vertical through fifth scale anterior to dorsal-fin origin in specimens smaller than 35 mm SL, closer to dorsal-fin origin in larger specimens. Anterior profile of head angular in lateral view, more rounded in specimens smaller than 100 mm SL. Dorsal profile of head varying from slightly convex in specimens smaller than 100 mm SL to almost straight in specimens larger than 130 mm SL. Dorsal margin of orbit located at horizontal to through dorsal profile of head in specimens smaller than 100 mm SL but not reaching dorsal profile of head in specimens larger than 130 mm SL. Dorsal profile of body slightly convex from vertical through first series of scale of body to dorsal-fin origin in specimens smaller than 130 mm SL and almost straight in larger specimens (ca. 280 mm SL); straight and posteroventrally inclined along dorsal-fin base; straight and less inclined to slightly concave from vertical through base of last dorsal-fin ray to origin of dorsal most procurrent caudalfin ray. Latter portion of profile slightly more concave in specimens smaller than 130 mm SL. Ventral profile of lower jaw distinctly angular in region of dentary symphysis, straight and slightly inclined from vertical through anterior nostril to posterior margin of lower jaw. Medial margins of contralateral dentaries running in parallel ( Fig. 1 a-c). Ventral profile of body slightly convex to pelvic-fin origin; approximately straight from latter point to anal-fin origin; straight and posterodorsally inclined along anal-fin base; slightly concave from last analfin ray to anterior most ventral procurrent caudal-fin ray.

Upper jaw slightly shorter than lower jaw. Posterior portion of maxilla dorsally enlarged and extending medial of anterior margins of second and third infraorbitals. Upper and lower lips fleshy with short projections of skin covering canines externally. Anterior nostril tubular with anterior slit along its distal half. Anterior and posterior nostrils situated along horizontal through center of orbit, anterior nostril two-thirds of orbital diameter from anterior margin of orbit; posterior nostril midway between anterior margin of orbit and anterior nostril. Eye proportionately larger in smaller specimens. Infraorbital bones well developed and horizontally elongate. Infraorbitals 3, 4, and ventral portion of 5 partially covering preopercle. Ventral margin of infraorbital 3 and posterior margins of infraorbitals 4, 5, and 6 convex. Small specimens (ca. 35 mm SL) with infraorbital 3 excluded from orbital rim and proximal ends of infraorbitals 2 and 4 in contact. Larger specimens (ca. 130 mm SL) with infraorbital 4 barely reaching orbital rim and infraorbital 5 gradually separated from rim. Proximal ends of infraorbitals 2 and 6 almost meeting in some of largest specimens (ca. 280 mm SL).

Teeth in both jaws conical or canine. Premaxillary teeth in single row. First premaxillary tooth large canine, second, sixth and eighth teeth medium sized. Seventh tooth canine almost as large as anterior most premaxillary canine. Third to fifth and ninth premaxillary teeth small. Maxilla with single row of approximately 32 relatively small teeth, except for very welldeveloped canine-like fourth tooth. Dentary with anterior external row of teeth and posterior internal row. External series with four anterior small teeth, followed by two well-developed canines, with posterior canine larger than anterior canine and followed by 8 conical teeth slightly smaller than anterior most dentary canine. Internal series beginning at length of nearly one conical tooth posterior to last conical tooth of external row and formed of approximately 11 very small teeth. Accessory ectopterygoid and ectopterygoid toothed; latter with series of small conical teeth along its ventrolateral margin and with many smaller viliform teeth on its ventromedial surface. Endopterygoid edentulous.

Distal margins of all fins rounded. Total dorsal-fin rays 12-14 (n = 75; ii,11; ii, 10 in two specimens and ii, 12 in five specimens). Dorsal fin located at midbody, its origin at vertical through approximately third scale anterior on series along pelvic-fin origin. Length of longest dorsal-fin rays two-thirds of body depth.Anal-fin base short. Total anal-fin rays 9-10 (n = 75; ii,8, ii, 7 in five specimens). Tip of depressed dorsal fin reaching vertical through anal-fin origin. Specimens smaller than 35 mm SL with tip of anal fin (third to sixth branched rays) reaching origin of anterior most ventral procurrent ray of caudal fin. Total pectoral-fin rays 12-14 (n = 70; i,11-13; mode: i,12, n = 40). Pectoral-fin origin located at vertical through central portion of opercle. Tip of pectoral fin separated from pelvic-fin origin by four to six scales. Pectoral and pelvic fins of similar size and slightly larger than anal fin. Pelvic-fin rays i,7 (n = 75, i, 5 in one specimen). Pelvic-fin origin situated at midbody approximately three scales posterior to vertical through dorsal-fin origin. Tips of pelvic fin separated from vertical through anal-fin origin by four or five scales. Caudal-fin rays i,15,i (n = 71, 14 branched rays in one specimen).

Well developed cycloid scales imbricated along body. Dorsal scales begin in series at posterior margin of parietals and overlap supraoccipital spine. Last vertical series of scales on caudal peduncle forms slightly convex arch on caudal-fin. Anterior margin of scales with small recess and posterior margin rounded. Approximately twelve radii extending from center of scale to its anterior margin and around twenty-five radii, some anastomosed, extending from center of scale to dorsal, posterior and ventral margins. Lateral line straight and complete, extending from posteroventral margin of supracleithrum to posterior most scale in body. Lateral line with 38-43 perforated scales (n = 74, 38 in two specimens; mode: 41, n = 24) ( Table 2). Lateral-line scales with single laterosensory canal. Longitudinal series of scales between lateral line and dorsal-fin origin 5.5 (n = 75). Longitudinal series of scales between lateral line and pelvic-fin origin 4.5- 5.5 (n = 75; mode: 5.5, n = 72). Longitudinal series of scales around caudal peduncle 18-20 (n = 73; 18 scales in two specimens).

Approximately eight gill rakers on first epibranchial, most in form of small denticulated plates. Lower branch of first branchial arch with five or six more elongate rakers and approximately 10 plate-like rakers (n = 8). Laterosensory canal along ventral surface of dentary with 4-6 pores (n = 75; mode: 5, n = 66) ( Table 3).

Color in alcohol. Ground coloration of head and body dark to light brown, darker dorsally and paler ventrally. Single dark midlateral stripe along lateral line separating dark dorsal from lighter ventral region. Stripe more evident in specimens smaller than 130 mm SL, the only color feature in very small specimens (ca. 35 mm SL). Specimens larger than 100 mm SL with five or six dark blotches along dark longitudinal stripe, some of them connected with contralateral blotch by dark dorsal saddle. Dorsal surface of head dark brown. Lips with alternating dark and light, thin, vertical bands. Ventral surface of head white. Coloration of infraorbital region and dorsal surface of head similar. Many specimens with two dark stripes radiating posteriorly from eye across opercular series and with third dark stripe extending posteroventrally from eye along infraorbital 2. Ground coloration of opercular series dark brown. Opercular membrane usually lighter than opercle.

All fins light brown and lighter than body, with dark spots on rays and interradial membrane forming pattern of irregular dark stripes. Stripes of anal and caudal fins wider than those of dorsal fin with stripes more irregular in anal fin. Pectoral, pelvic, and anal fins with paler pattern than dorsal and caudal fins. Ventral surfaces of pectoral and pelvic fins either lighter than, or with same pattern, as dorsal surface of fin, but with pattern less conspicuous.

Distribution. Coastal rivers of northeastern Brazil, from the rio Paraguaçú in Bahia State to rio Jequitinhonha in Minas Gerais and Espírito Santo States, including rio de Contas and rio Pardo ( Fig. 3 ).

Remarks. Specimens used by Spix & Agassiz (1829) to describe Erythrinus brasiliensis and deposited in the Zoologische Staatssammlung München, were destroyed during a bombing raid in the Second World War ( Terofal, 1983; Kottelat, 1988; Neumann, 2006). The holotype of Erythrinus brasiliensis is not among the specimens studied by Spix & Agassiz in the Musée d’Histoire Naturelle, Neuchâtel, and is therefore judge to be missing. Its original description, however, mentioned the “tongue […] edentate” and “branches of the lower jaw rather distant from each other and somewhat spread out below […] parallel to one another” [our translation]. These observations confirm that E. brasiliensis is a member of the Hoplias lacerdae group. Data presented in this study match the remaining information in the original description. Since the holotype of E. brasiliensis is lost, and in order to clarify the taxonomic status of this nominal species, a neotype is designated in accordance to Article 75 of the International Code of Zoological Nomenclature ( ICZN, 1999). The taxon is redescribed herein, with characters diagnosing it from other members of the genus.

Castelnau (1855) identified some specimens collected in the rio Carandaí, a tributary of rio das Mortes, Minas Gerais State, as Erythrinus brasiliensis and stated that the specimens attained 50 cm SL. According to the results of the present study, Hoplias brasiliensis attains only 30 cm SL, being the smallest among species of the H. lacerdae group. The river mentioned by Castelnau (1855) belongs to the rio Grande basin, upper rio Paraná, and the available name for the specimens cited by that author is H. intermedius , a form that can reach 50 cm SL.

Rivers in which Hoplias brasiliensis occurs drain the Atlantic coast of Brazil, from the rio Paraguaçu to the rio Jequitinhonha. The region of occurrence of this species lies south and east of the rio São Francisco and north of the rio Doce. Pellegrino et al. (2005) proposed that the origin of rio Doce, together with the formation of current rio São Francisco, were responsible for isolating this region. The area from southern coastal Bahia to the northern portion of Espírito Santo is inhabited by many endemic taxa, and is considered a “hotspot” of biodiversity ( Bizerril, 1994; Chomitz et al., 2005; Galindo-Leal & Câmara, 2005; Rocha et al., 2005). Examples of endemic fishes from that region can be found in the studies of Menezes (1988), Weitzman et al. (1988), Zanata & Akama (2004), Britto et al. (2005), Garavello (2005), Lucinda (2005), Bertaco & Lucena (2006), Sarmento-Soares et al. (2006a, b), Zanata & Camelier (2009), among others. Many other organisms are also known to be endemic to this region, including plants ( Harley, 1988; Soderstrom et al., 1988; Thomas et al., 1998), amphibians (Cruz & Pimenta, 2004), lizards ( Rodrigues et al., 2002; Pellegrino et al., 2005), birds ( Silva et al., 2004; Silveira et al., 2005), and mammals (Emmons & Vucetich, 1998; Ventura et al., 2004).

Figures

Fig. 4. Hoplias brasiliensis, neotype, MZUSP 45483, 162.9 mm SL, rio Paraguaçú near Iaçú, Bahia State, Brazil.

Fig. 1. Ventral view of head of (a) Hoplias curupira, MZUSP 24403, 55.5 mm SL; (b) H. curupira, MZUSP 24403, 92.2 mm SL; (c) H. curupira, MZUSP 24403, 162.2 mm SL and (d) H. malabaricus, MZUSP 90416, 101.7 mm SL.

Fig. 3. Map of South America showing geographic distribution of species of the Hoplias lacerdae group based on material examined in this study. Some symbols may represent more than one lot. Numbers indicate type localities of (1) Hoplias australis (squares); (2) H. brasiliensis (losanges); (3) H. curupira (triangles); (4) H. intermedius (dots); and (5) H. lacerdae (inverted triangles).