Neoplecostomus bandeirante, Roxo, Fábio F., Oliveira, Claudio & Zawadzki, Cláudio H., 2012

Roxo, Fábio F., Oliveira, Claudio & Zawadzki, Cláudio H., 2012, Three new species of Neoplecostomus (Teleostei: Siluriformes: Loricariidae) from the Upper Rio Paraná basin of southeastern Brazil, Zootaxa 3233, pp. 1-21 : 4-8

Neoplecostomus bandeirante , new species

Figure 1 , Table 1.

Neoplecostomus sp. 1. Reusing et al. (2011): 497 [photo; Figure 1 a compares this species with Neoplecostomus sp. 2]

Holotype: MZUSP 110363 (1 male, 109.9 mm SL), Brazil, São Paulo state, municipality of Salesópolis, Rio Paraitinguinha, Rio Tietê basin, 23°31’25”S 43°53’22”W, 14 Sep 2006, R. Devidé, J.C.P. Alves, L.R. Paiva.

Paratypes: All paratypes are from São Paulo state in Brazil, in the municipality of Salesópolis, Rio Paraitinguinha, Rio Tietê basin. DZSJRP 14881 (2 males, 92.1–95.4 mm SL) collected with holotype. LBP 2861 (8 males, 82.2–106.4 mm SL; 16 unsexed, not measured) 23°31’37”S 45°45’53”W, 20 May 2005, E.R.M. Martinez et al. (GenBank numbers GQ214793 to GQ214796 , and FJ434534 ). LBP 3578 (1 female, 41.3 mm SL; 1 unsexed, not measured), 23°30’40”S 45°51’32”W, 21 Jul 2008, R. Devidé et al. LBP 3921 (3 males, 58.7–94.9 mm SL; 2 females, 59.0– 82.5 mm SL; 5 unsexed, not measured), 23°31’25”S 43°53’22”W, 14 Sep 2006, R. Devidé et al. LBP 4993 (2 females, 40.8–74.3 mm SL; 1 unsexed, not measured), 23°30’40”S 45°51’32”W, R. Devidé et al. MZUSP 59117 (1 male, 46.1 mm SL; 1 female, 56.0 mm SL), 23°31’37”S 45°45’52”W, 17 Dec 1999, L.R. Malabarba et al. MZUSP 59118 (1 female, 58.2 mm SL), 23°35’02”S 45°46’43”W, 17 Dec 1999, L.R. Malabarba et al. MZUSP 59139 (1 unsexed, not measured), 23°31’37”S 45°45’52”W, 17 Dec 1999, L.R. Malabarba et al. MZUSP 87141 (6 unsexed, not measured), coordinates unknown, 15 May 1999, M.R. Britto et al. NUP 6103 (1 male, 101.7 mm SL; 1 female, 74.3 mm SL; 18 unsexed, not measured); 23°30’40”S 45°51’32”W, 21 Jul 2008, R. Devidé.

Diagnosis: Neoplecostomus bandeirante differs from all other congeners by the presence of moderate keels along each lateral series of plates (vs. keels absent in all series of plates, see Figure 2 ), and by first plates in the mid-ventral series that are smaller in length than the area surrounding each plate (vs. greater, see Figure 3 ). These characteristics are more evident in mature males. Additionally, N. bandeirante differs from all other congeners, except N. selenae and N. yapo , due to the presence of odontodes along the snout margin and the ridge over the eyes that are slightly larger than the remaining odontodes on the head (vs. odontodes along the snout margin and ridge over eyes similar in length to the remaining odontodes on the head). Neoplecostomus bandeirante differs from N. selenae and N. yapo by the absence of a swollen integument around the enlarged odontodes on the snout margin and the ridge over the eyes in mature males (vs. presence of swollen integument around the enlarged odontodes on the snout margin and ridge over eyes in mature males).

Description: The counts and measurements are presented in Table 1. Body elongated and depressed; greatest width at cleithrum, narrowing to caudal peduncle. Dorsal body profile gently convex, elevating from snout tip to dorsal-fin origin and descending to first procurrent caudal-fin ray; greatest body depth at dorsal-fin origin. Trunk and caudal peduncle dorsally rounded in cross-section; body ventrally flattened to anal-fin origin, flattened to slightly rounded to caudal fin. Dorsal body surface completely covered by dermal plates, except for naked area around dorsal-fin base. Snout tip with small naked area.

Ventral head surface naked except for plated area bearing odontodes in front of gill openings; abdomen with conspicuous, small dermal platelets between insertions of pectoral and pelvic fins, forming thoracic shield surrounded by naked areas. Head wide and depressed; head and snout rounded in dorsal view; interorbital space straight to slightly concave in frontal view; median ridge formed by mesethmoid rising from snout tip to area between nares, more evident in larger specimens; pronounced ridge from nares to superior margin of orbit. Snout convex in lateral profile; moderately enlarged odontodes and slightly swollen skin along lateral margins of snout, more evident in mature males. Eye moderately small (6.7–10.8 mm of HL), dorsolaterally placed. Lips well developed and rounded; lower lip far from reaching pectoral girdle and covered with papillae, wider anteriorly; two to three irregular and conspicuous rows of large and transversally flattened papillae, just posterior to dentary teeth; posterior row of papillae distributed along entire dentary ramus. Maxillary barbel short, coalesced, usually its tip not free from lower lip. Teeth long, slender and bicuspid; mesial cusp longer than lateral; dentary ramus forming an angle of approximately 125–130º.

Dorsal-fin origin slightly posterior to vertical passing through pelvic-fin origin; nuchal plate not covered by skin; dorsal-fin spinelet half-moon shaped and slightly wider than dorsal-fin spine base; dorsal-fin locking mechanism absent; dorsal fin with one flexible spine followed by seven branched rays; its posterior margin slightly rounded, not reaching the end of pelvic-fin rays when adpressed. Well-developed and always present adipose fin, preceded by azygous plate. Pectoral fin with one spine and six branched rays; spine depressed and curved inward (more pronounced in larger specimens), shorter than longest branched ray; posterior margin slightly concave, reaching half pelvic-fin ray length when adpressed. Pelvic fin with one unbranched ray and five branched rays; posterior margin nearly straight, reaching anal-fin insertion in most of the specimens when adpressed; pelvic-fin unbranched ray ventrally flattened, with dermal flap on its dorsal surface in males. Anal fin with one flexible unbranched ray and five branched rays; posterior margin nearly straight. Caudal fin furcate; lower lobe longer than upper; 14 branched rays. Pectoral spine and unbranched pelvic-fin rays with odontodes on lateral and ventral portions; anal-fin unbranched ray with odontodes only ventrally.

Color in alcohol: Ground color of dorsal surface of head and body grayish; head, dorsum, flanks and fins covered by some inconspicuous lighter dots of variable sizes. Dorsal color pattern, even in mature larger individuals, retains the generic juvenile color pattern of five transverse dark bands: the first through supraoccipital, the second anterior to dorsal fin, the third posterior to dorsal fin, the fourth at adipose fin, and the last at caudal-peduncle posterior portion. Head usually with two light, short and parallel lines anterior to nares, bordering the naked area on snout tip; a pale spot on naked area of snout tip. Orbital margin slightly lighter, mainly on its superior portion; small pale spot on interorbital space, inconspicuous in some specimens.

Lateral portion of body with an upper darker region and a lower lighter one, just below lateral line, not easily visualized in large specimens. Dorsal fin with irregular series of dark spots on rays. Caudal fin irregularly dark at base and distal portion of rays, leaving two lighter areas on median portion and rays tips, in some specimens. Pectoral, pelvic, anal and adipose fins with dark dots forming irregular bands usually diffuse. Ventral surface of head and abdomen mostly unpigmented, except lateral margins of body and from pelvic fin to caudal-fin base. Upper lip dark brown, except for its light narrow margin.

Sexual dimorphism: Males bear a papilla in the urogenital opening, and a membrane along dorsal portion of the unbranched pelvic-fin ray ( Figure 4 ). These characters were observed in nominal Neoplecostomus species and in the three new species described herein. Males seem to reach a greater length as seen in the paratypes, and odontodes on head seem to be slightly more evident on larger mature males.

Distribution: The species is found only in the type-locality of Rio Paraitinguinha, Rio Tietê basin, in the municipality of Salesópolis, São Paulo state, Brazil ( Figure 5 ).

Etymology: This species was named bandeirante in honor of the early explorers of São Paulo, who, from the beginning of the 16th to the 18th centuries, ventured into the unmapped interior of Brazil in excursions named “bandeiras”. The purpose of the excursions was to hunt for indigenous people and submit them to enslavement and to search for mineral wealth, such as silver, gold, and diamonds. Despite playing an apparent negative role in history, their work was essential for the establishment of new cities and for the geographic demarcation of the Brazilian territory. A noun in apposition.

Figures

FIGURE 1. Neoplecostomus bandeirante, MZUSP 110363, (male) SL = 109.9 mm, holotype from Rio Paraitinguinha in the municipality of Salesópolis.

FIGURE 2. Lateral keels. (a) Neoplecostomus bandeirante, LBP 3921, 109.9 mm SL, moderate keels along each lateral series of plates. (b) Neoplecostomus botucatu, NUP 8015, 90.7 mm, keels absent in all series of plates.

FIGURE 3. Lateral series of plates in two specimens of Neoplecostomus. (a) Neoplecostomus bandeirante, LBP 3921 109.9 mm SL, bar = 0.78 mm. (b) Neoplecostomus botucatu, NUP 8015, 90.7 mm, bar = 1.24 mm. ml = mid-lateral series; mv = midventral series; v = ventral series.

FIGURE 4. Sexual dimorphism in Neoplecostomus species. (a) Dorsal view of a male Neoplecostomus botucatu, MZUSP 110362, 84.3 mm SL; (b) Picture corresponding to the highlighted area in (a) showing the membrane in the pelvic fin; (c) Ventral view of a male Neoplecostomus botucatu, MZUSP 110362, 84.3 mm SL; (d) Picture corresponding to the highlighted area in (c) showing the urogenital papilla; (e) Dorsal view of a female Neoplecostomus botucatu, LBP 8065, 75.3 mm SL; (f) Picture corresponding to the highlighted area in (e) showing the absence of a membrane in the pelvic fin; (g) Ventral view of a female Neoplecostomus botucatu, LBP 8065, 75.3 mm SL; (h) Picture corresponding to the highlighted area in (g) showing the absence of a urogenital papilla. Scale bars = 1 mm.

FIGURE 5. Distribution of Neoplecostomus samples used in the molecular analysis. Yellow triangles refer to the former, nominal species and red triangles refer to the new species. The geographic position is shown in the Table 2.