Peckoltia compta, Oliveira, Renildo Ribeiro De, Zuanon, Jansen, Py-Daniel, Lucia Rapp & Rocha, Marcelo Salles, 2010

Oliveira, Renildo Ribeiro De, Zuanon, Jansen, Py-Daniel, Lucia Rapp & Rocha, Marcelo Salles, 2010, Peckoltia compta, a new species of catfish from the Brazilian Amazon, rio Tapajós basin (Siluriformes: Loricariidae), Zootaxa 2534, pp. 48-56 : 49-54

Peckoltia compta new species

( Figs. 1 , 2 )

Holotype: INPA 6865, 56.6 mm SL, Brazil, Pará, Itaituba, Pimental, rio Tapajós downstream from the confluence with rio Jamanxim, 04º41’06”S 056º23’07”W. 21 October 1991, L. Rapp Py-Daniel & J. Zuanon.

Paratypes: Brazil, Pará: INPA 6782, 4, 1cs, 45.3–61.5 mm SL, ilha da Terra Preta, rio Jamanxim, 04º58’06.1”S 056º29’12.3”W. 20 October 1991, L. Rapp Py-Daniel and J. Zuanon. MCP 45008, 1, 42.2 mm SL, same data as INPA 6782. MPEG 18643, 1, 44.2 mm SL, ilha da Terra Preta, rio Jamanxim, 04º58’06.1”S 056º29’12.3”W. 20 October 1991, L. Rapp Py-Daniel and J. Zuanon. MZUSP 105752, 1, 58.9 mm SL, ilha da Terra Preta, rio Jamanxim, 04º58’06.1”S 056º29’12.3”W. 19 October 1991, L. Rapp Py-Daniel and J. Zuanon. INPA 6975, 4, 45.5 mm SL (3 juveniles not measured), Itaituba, rio Tapajós downstream from the confluence with rio Jamanxim, 04º41’06”S 056º23’07”W. 23 October 1991, L. Rapp Py-Daniel and J. Zuanon.

Diagnosis. Peckoltia compta can be distinguished from all of its congeners by presenting a clear stripe inside the dark brown bars running from snout tip to anterior margin of eyes (vs. absence of the clear stripe and a mottled appearance in P. vittata , and a mix of vermiculations and spots on the head of the other congeners). It can be further distinguished from its congeners (except from P. b a c h i) by the presence of small dark brown spots only on fin rays, rarely reaching the interradial membranes (vs. dark spots on interradial membranes or dark stripes covering the whole fin or plain). It can be distinguished from P. b a c h i by the interorbital distance, 31.1-32.9 (vs. 51.5–71.0% HL). Peckoltia compta can be distinguished from all its congeners except P. bachi , P. braueri , P. brevis , P. cavatica , P. lineola and P. vittata by its larger cleithral width 32.3–34.6 (vs. 20.8–32.4% SL). It can be distinguished from all its congeners except P. cavatica , P. s nethlageae and P. sabaji by its smaller head depth 57.8–62.2 (vs. 63.5–87.7% HL).

Description. Morphometric data presented in Table 1. Small-sized loricariid, with largest specimen measuring 61.5 mm SL. Body section rounded anteriorly in dorsal view, becoming gradually narrower from dorsal-fin origin to caudal fin. Body short and deep, with deepest point at insertion of dorsal fin. Dorsal profile convex, rising as straight line from snout to orbit, becoming flat from orbit to dorsal-fin insertion and gently declining from this point to end of caudal peduncle. Head short and without ridges or carenae. Head and snout completely covered by strong odontodes. Few (around five) hypertrophied odontodes on cheek plates, such odontodes completely exposed and partly encased in depression above cleithrum. Eye laterodorsal with small but conspicuous iris without diverticulum or flap; orbit round.

TABLE 1. Morphometrics of Peckoltia compta new species. SD= standard deviations; L= length; W=width; D=distance; SL= standard length; HL= head length; Dp=depth; Min= minimum; Max= maximum.

Parieto-supraoccipital short, bearing small but conspicuous crest. Parieto-supraoccipital limited posteriorly by set of predorsal plates arranged as one disjunct pair, followed by one or two closely attached pairs plus one single plate immediately anterior to dorsal-fin spinelet.

Lateral line with 24–25 plates, four to five plates between dorsal and adipose fins, 10–12 plates between anal and caudal fins. Body not carenate or keeled. Plates of midventral series behind pectoral fin slightly bent; plates encircling dorsal-fin base also slightly bent. Caudal peduncle deep and covered by five series of plates. All body plates covered by strong odontodes.

Gular area naked, gill-openings small. Abdomen almost completely naked except for some small patches of odontodes between pectoral fins of large specimens; single plate between urogenital opening and anal-fin insertion.

All fin rays carrying odontodes, more developed on first (undivided) ray. Dorsal fin short, composed by spinelet, one spine, and seven soft, segmented and branched rays (II+7). Dorsal-fin spine with small odontodes along its anterior margin. Dorsal-fin spinelet triangular and with locking mechanism. Dorsal fin reaching preadipose plate when adpressed; extended membrane between last dorsal-fin ray and dorsum absent. Pectoral fin with spine and six soft, segmented and branched rays (I+6); locking mechanism present. Pectoral fin reaching proximal third of pelvic when adpressed. Pelvic fin with six rays; first thickened and unbranched and five branched (i+5). Pelvic-fin tip reaching posterior end of anal-fin base. Anal fin with 5 rays; first thickened and unbranched and four branched (i+4). Adipose-fin spine with small odontodes on its anterior surface. Caudal fin slightly emarginate. Caudal fin with 16 rays, two external thickened, unbranched and bearing small odontodes plus 14 inner branched rays (i+14+i).

Mouth small; lips well developed and densely papillate. Border of lower lip densely fringed with delicate papillae. Buccal papillae small and low. Maxillary barbel nearly equal to horizontal orbit diameter. Premaxillary of similar size of dentary. Dentaries always forming acute angle. Premaxillary teeth 18–27, dentary teeth 17–27. Premaxillary and dentary teeth of similar size, small, strong, and unevenly cuspidate with internal cusp larger than external.

Color in alcohol. Preserved specimens of Peckoltia compta with light brown body covered with transversal dark brown large and irregular bars. Bars slanted anteroposteriorly and roughly Y-shaped in lateral view, forming regular design resembling a mask around dorsal-fin base. Some large round dark blotches on flanks between dark bands. Head pigmentation (in dorsal view) composed by black anostomosing stripes at interorbital region, extending laterally to snout edge at interopercular area. Snout with longitudinal black mark with thin clear stripe in the middle, extending from internarinal space to snout edge, flanked by similar marks from each nare to snout edge. Snout marks roughly resembling a keyboard in dorsal view. All fins with dark brown blotches on rays, very rarely reaching interradial membranes. Black blotch at tip of adipose fin spine. Abdominal surface plain white.

Color in life ( Fig. 1 ). Overall striped and spotted color pattern as described above only more conspicuous on living specimens, with yellowish color background and very dark lines and spots, and hyaline interradial membranes.

bachi braueri brevis caenosa cavatica compta furcata

Percents of standard length

Head L 34.6–39.1 Cleithral W 25.7–31.1 31.4–33.1 20.8–28.3 Thorax L 25.1–31.3 Pectoral–spine L 31.5–35.2 Postanal L 33.2–38.3 31.3–36.9 28.0–31.9 32.2–39.5 Dorsal spine L 30.0–41.8 26.7–31.9 Dorsal-adipose D 14.9–21.4 10.0–13.0 Percents of head length

Snout L 51.6–55.7 Internares W 15.5–24.0 13.8–20.7 9.9–13.9 Interorbital W 51.5–71.0 38.7–53.7 36.9–56.3 31.1–32.9 Head Dp 66.9–76.0 66.3–75.9 63.6–77.4 66.6–74.0 61.8–71.8 57.8–62.2 66.6–72.1 Dentary L 5.4–11.4 12.5–17.0 Premax. L 5.5–10.5 13.3–17.3

continued.

lineola oligospila sabaji snetlhageae vermiculata vittata

Percents of standard length

Head L 28.4–34.5

Cleithral W 24.7–31.4 21.8–27.9 28.7–31.2 28.9–29.5 Thorax L 20.0–23.8 19.4–25.1 21.2–24.7 Pectoral–spine L 28.6–29.7 Postanal L 34.3–38.8 35.7–41.0 33.9–35.6 Dorsal spine L 31.9–48.9

Dorsal-adipose D 14.1–17.1 16.0–20.3 15.5–16.9 Percents of head length

Snout L 58.0–61.2 57.2–63.3 55.9–61.8 Internares W 14.9–16.4 Interorbital W 38.5–51.5 35.2–49.0 38.2–41.8 Head Dp 68.9–77.9 68.2–80.4 70.5–75.6 63.5–87.7 Dentary L

Premax. L 8.0–11.8 11.2–12.7

Distribution. The specimens were collected on two localities: in rio Tapajós, near the village of Pimental, downstream from the confluence with rio Jamanxim, and in rio Jamanxim around ilha da Terra Preta ( Figure 3 ). The Tapajós and Jamanxim are clear water rivers and the specimens were collected in moderate to fast flowing waters, over a rocky bottom.

Etymology. The specific epithet, compta , is from the Latim comptus for ornamented, adorned. The name is a reference to the particular bold color pattern shown by this new species. Treated as an adjective.

Figures

FIGURE 1. Peckoltia compta new species, INPA 6865, holotype, 56.6 mm SL, photographed immediately after capture. Photo by J. Zuanon.

FIGURE 2. Peckoltia compta new species, INPA 6865, holotype, 56.6 mm SL in lateral, dorsal and ventral views. Photo by R. R. de Oliveira.

FIGURE 3. Map of the Brazilian Amazon basin, showing in detail the rio Tapajós drainage with its main tributaries and the collecting localities of Peckoltia compta new species. Square: Pimental; black circle: ilha da Terra Preta.