Neoplecostomus botucatu, 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 : 9-12

Neoplecostomus botucatu , new species

Figure 6 , Table 1.

Neoplecostomus paranensis . Zawadzki et al. (2008): 36 [photo; Figure 1 a and 1b compares absent and undeveloped adipose fins, respectively]; Alves et al. (2005): 128 [cytogenetics; Ribeirão Hortelã, tributary of Rio Pardo].

Holotype: MZUSP 110364 (1 male, 98.6 mm SL), Brazil, São Paulo state, municipality of Botucatu , Córrego Águas de Madalena, tributary of Rio Pardo, Rio Paranapanema basin, 22°59’25”S 48°25’37”W, 22 Mar 2009, F.F. Roxo, M.F. Pazian, M.N. Mehanna, B.F. Melo.

Paratypes: All paratypes are from São Paulo state in Brazil, in the municipality of Botucatu , Córrego Águas de Madalena, tributary of Rio Pardo, Rio Paranapanema basin. DZSJRP 14879 (3 males, 62.3–79.9 mm SL; 3 females, 56.1–78.1 mm SL) collected with holotype. LBP 2937 (1 unsexed, 37.2 mm SL), 22°59’25”S 48°25’37”W, 12 Apr 2005, R. Devidé et al. LBP 2969 (1 male, 58.8 mm SL; 1 female, 59.4 mm SL), 22°59’25”S 48°25’37”W, 12 Apr 2005, R. Devidé et al. LBP 7525 (5 males, 91.0– 102.2 mm SL; 1 c & s, 98.4 mm SL; 15 females, 56.2–98.6 mm SL), 22°59’25”S 48°25’37”W, 15 Nov 2008, F.F. Roxo et al. (GenBank numbers GQ214784 to GQ214788 ). LBP 8065 (3 males, 73.5–88.2 mm SL; 9 females, 67.5–84.9 mm SL), 22°59’25”S 48°25’37”W, 22 Mar 2009, F.F. Roxo et al. MZUSP 110362 (2 males, 85.3–89.8 mm SL; 1 female, 76.7 mm SL). 22°59’25”S 48°25’37”W, 22 Mar 2009, F.F. Roxo et al. NUP 8015 (1 male, 90.7 mm SL; 2 females 71.3–75.8 mm SL), 22°59’25”S 48°25’37”W, 24 Aug 2008, R. Devidé et al. NUP 8016 (1 male, 69.8 mm SL), 22°59’25”S 48°25’37”W, 31 Jul 2008, R. Devidé et al. NUP 8118 (1 male, 95.9 mm SL) 22°59’25”S 48°25’37”W, 22 Mar 2009, F.F. Roxo et al.

Diagnosis: Neoplecostomus botucatu differs from all other congers, except N. paranensis , due to the lack of, or reduction in size of, the adipose fin (vs. adipose fin moderate to well developed and always present). Neoplecostomus botucatu differs from N. paranensis by the presence of conspicuous dark spots all over the body and the absence of some fins and dorsal bands (vs. lacking conspicuous dark spots and having five dark bands on dorsum evident, Figure 7 ). Additionally, N. botucatu can also be differentiated from N. paranensis by a greater head depth 55.6–63.9% in head length and greater mandibular width 12.5–17.8% in head length (vs. 44.4–55.4% and 8.4– 12.4%, respectively).

Description: 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 caudal-fin procurrent 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, excepting for naked area around dorsal-fin base. Snout tip naked.

Ventral head surface naked except by plate 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; in some specimens some additional isolated platelets near pectoral-fin base. Head wide and depressed; head and snout rounded in dorsal view; interorbital space slight concave in frontal view; median ridge formed by the mesethmoid slightly rising from snout tip to area between nares, more evident in specimens up to 70 mm of SL. Weak ridge from snout to superior margin of orbit. Snout gently convex in lateral profile. Mature male with moderately enlarged odontodes and distinct swollen skin on whole head. Eye moderately small (8.0–10.6% of HL), dorsolaterally placed. Lips well developed and rounded; lower lip almost reaching pectoral girdle and covered with papillae, wider anteriorly; two or three irregular and conspicuous rows of large and transversally flattened papillae, just posterior to dentary teeth; posterior row of papillae occupying the mesial half of dentary ramus. Maxillary barbel short and coalesced with lower lip, generally with free tip. Teeth long, slender and bicuspid; mesial cusp longer than lateral; dentary ramus forming an angle of approximately 100–120º.

Dorsal-fin origin slightly posterior to vertical passing through pelvic-fin origin; nuchal plate not covered by skin; dorsal-fin spinelet very short, usually composed by a transversal row of single odontodes, absent in some specimens; dorsal-fin locking mechanism absent, dorsal-fin with one flexible spine, followed by seven branched rays; its posterior margin straight, not reaching the end of pelvic-fin rays when adpressed; ill-developed and not always present adipose fin (see Zawadzki et al. 2008 Fig. 1 A and 1B). Pectoral fin with one spine and six branched rays; spine depressed and curved inward (more pronounced in larger specimens), shorter than longest branched ray, its posterior margin nearly straight, reaching about one-third pelvic-fin unbranched ray length when adpressed. Pelvic fin with one unbranched ray and five branched rays; its posterior margin straight to slight convex, not to almost reaching anal-fin insertion 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; its posterior margin straight to slight convex. Caudal fin moderately furcate; lower lobe slightly longer than upper; 14 branched rays. Pectoral spine and pelvic-fin unbranched ray 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 yellowish. Head, dorsum, flanks and fins covered by numerous conspicuous dark spots of variable shapes and sizes. Dorsal color pattern in specimens up to 60.0 mm SL retains the generic juvenile color pattern of five transverse dark bands: the first through supraoccipital, the second anterior to dorsal fin, the third at dorsal-fin end, the fourth at adipose fin, and the last at caudal-peduncle posterior portion. In larger specimens, the dark bands are no longer distinguished; orbital margin lighter, mainly on its superior portion.

All fins, with irregular series of dark dots on rays, sometimes forming irregular, diffused, transverse bands. Ventral surface of head and body mostly unpigmented, except for some brown, faded and scattered chromatophores on lateral margins of body between pelvic fin and caudal-fin base. Upper lip dark brown, except for its light narrow margin.

Sexual dimorphism: The male has a papilla in the cloaca, and a membrane in the ventral fin, both of which are absent in the female ( Figure 4 ). Males reach a greater length, as observed in paratypes.

Distribution: Neoplecostomus botucatu is found only in its type-locality of Córrego Águas de Madalena, tributary of Rio Pardo, Rio Paranapanema basin, in the municipality of Botucatu , São Paulo state, Brazil ( Figure 5 ).

Etymology: Named after the municipality of Botucatu , the city where the specimens were collected. 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 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.

FIGURE 6. Neoplecostomus botucatu, MZUSP 110364, SL = 98.4 mm, holotype from Córrego Águas de Madalena in Botucatu municipality.

FIGURE 7. Picture showing the pattern of coloration in (a) holotype of Neoplecostomus paranensis (MZUSP 38572, 71.4 mm SL) showing four or five conspicuous dark bands on the dorsum and lack of dark spots; (b) holotype of Neoplecostomus botucatu (MZUSP 110364, 98.6 mm SL) showing conspicuous dark spots all over the body and fins, but no evidence of dorsal bands.