Peckoltia brevis ( La Monte 1935 )

Armbruster, Jonathan W., 2008, The genus Peckoltia with the description of two new species and a reanalysis of the phylogeny of the genera of the Hypostominae (Siluriformes: Loricariidae), Zootaxa 1822 (1), pp. 1-76 : 16-20

Peckoltia brevis ( La Monte 1935)

( Fig. 2c and 9–10 )

Hemiancistrus brevis La Monte, 1935:3 , fig. 2. Type locality: Near Sena Madureira , near mouth of River Macaua , tributary of Rio Iaco , itself a tributary to Rio Purus, Amazonas, Brazil. Holotype: AMNH 12602 .

Material Examined: BOLIVIA, Unknown state, Río Mamore - Río Madeira drainage: MNHN 1988–1083 , 2 , 65.1 –103.0, Isiboro, col. by, Luzanne and Loubens, October 1985 ; MNHN 1988–1084 , 1 , 92.6 , Chimimita, col. by, Luzanne and Loubens, November 1984 . BOLIVIA, Beni, Río Madeira - Río Amazonas drainage: USNM 305824 , 10 , 3 cs., 34.1–101.2, Ballivia Province, Rio Matos Below Road crossing, 48 Km E San Borja, 14°55’S, 066°17’W, col. by, Starnes, W. C.; Munroe, T.; Sarmiento J., 31 August 1987 .

BRAZIL, Acre, Rio Amazonas drainage: AMNH 12602 , Holotype, and USNM 94680 , 1 , 84.1 , vicinity of mouth of Rio Macauhan, a tributary of the Rio Yacu , which flows into the Rio Purus , col. by, B.A. Krukoff, 1934; MZUSP 50395 , 1 , 88.1 , Rio Juruá , Colocacão São João , 09°09’S, 072°41’W, col. by, Coleção Reserva Extrativista Alto Juruá , 8 July 1993. BRAZIL, Amazonas , Rio Amazonas drainage: MZUSP 23439 , Igarapé Tome , Ati Paraná, NW of Fonte Boa, 02°31’S, 066°06’W, col. by, EPA, 13 October 1968; INPA 4705 , 3 , 98.1 –106.0, Rio Japurã , Paraná do Mapixari, Lago Jarava, col. by, C. Pescad. de Tefe , 1 December 1979; MZUSP 57474 , Rio Solimões , above the Rio Purus , col. by, A. M. Zanata et al., 28 July 1996.

COLOMBIA, Amazonas, ICNMNH 7944 , Río Amazonas drainage, San Juan de Atacuan , Rio Amazonas , 10 July 1993 . COLOMBIA, Vichada, ICNMNH 5339 , Río Orinoco drainage, La Pinsonera, Río Bita , Puerto Carreño, Javier Climato, 23 Jan 1998 ; ICNMNH 11922 , Río Orinoco basin, Puerto Carreño, collected by Proyecto Ornamentales del Orinoco , February 2005 .

PERU, Loreto, Río Amazonas drainage: FMNH 111511 , 1 , 92.6 , Rio Chambira and small tributaries ca. 15.7 km above mouth in Rio Marañon , 05°00’S, 074°53’W, col. by, Chernoff, Wheeler, Klocek, Duvall and Onate, 4 September 1988 ; INHS 36873 , 1 , 95.5 , Río Itaya approximately 10 km S Santa Clara, col. by, aquarium dealer in Santa Clara , 25 July 1995 ; Peru , Loreto, Río Amazonas, INHS 43344 , 2 , 1 cs, 105.3–105.7 and SIUC 29784 , 2 , 58.5 – 73.3 , Río Itaya 11 km SSW Iquitos, 03°49’48”S, 073°18’03”W, col. by, J.W. Armbruster, M.H. Sabaj, et al., 6 August 1997 .

Diagnosis: Peckoltia brevis can be identified from all other Peckoltia except P. bachi , P. caenosa , P. lineola , and P. oligospila by having round spots on the head and abdomen; from P. bachi by having the spots on the head small (vs. large), the pelvic spines narrow (vs. wide), and the eye high on the head (vs. low); from P. caenosa and P. lineola by having none of the head spots combining to form lines; from P. caenosa by having spots on the abdomen (vs. vermiculations), by having bands in the dorsal (vs. light spots), and by having the dark and light bands on the caudal fin of about equal width (vs. light bands about 25% of width of dark bands); and from P. oligospila by lacking spots laterally behind the dorsal fin (vs. spots present on sides), and by having bands in the dorsal and caudal fins and dorsal saddles (vs. spots on the fins and body and saddles faint). Peckoltia furcata additionally has spots on the head, but not the abdomen and P. brevis can be further separated from P. furcata by having bands in the dorsal fin (vs. spots).

Description: Morphometrics in Table 2, counts based on 24 individuals unless otherwise stated. Largest specimen examined 105.7 mm SL. Body stout and fairly wide. Head gently sloped to parieto-supraoccipital. Parieto-supraoccipital with tall, rounded crest. Parieto-supraoccipital crest raised slightly above nuchal region. Nuchal region rises slightly to nuchal plate. Dorsal profile sloped ventrally to dorsal procurrent caudal-fin spines, then rising rapidly to caudal fin. Ventral profile flat to ventral procurrent caudal-fin spines and then sloping ventrally to caudal fin. Supraorbital ridge rounded, contiguous, but slightly offset medially from rounded ridge proceeding from anterior margin of orbit to anterolateral corner of anterior nare. Head contours smooth. Eye medium-sized.

Keels absent. Mid-ventral plates bent at their midline above pectoral fin to form ridge. Dorsal plates bent dorsally below dorsal fin to form ridges that converge at preadipose plate, dorsal surface flat between ridges. Five rows of plates on caudal peduncle. Abdomen fully covered in small plates except for small naked areas posterior to lower lip and at insertions of paired fins. First anal-fin pterygiophore exposed to form a platelike structure. Pair of lateral plates converging at midline between anus and exposed first anal-fin pterygiophore. 22–26 (mode 24) plates in the median series.

Frontal, infraorbitals, nasal, compound pterotic, sphenotic, and parieto-supraoccipital, supporting odontodes; opercle supporting odontodes in juveniles but not in adults, posterodorsal corner of opercle covered by one or two plates in adults. Odontodes on lateral plates not enlarged to form keels. Hypertrophied cheek odontodes 14–42 (N=13), longest almost reaching first mid-ventral plate in adults. Cheek plates evertible to approximately 90° from head. Odontodes on tip of pectoral-fin spine slightly hypertrophied.

Dorsal fin short, just reaching preadipose plate fin when adpressed; dorsal-fin spine same length as proceeding rays making edge straight. Dorsal-fin spinelet V -shaped, dorsal-fin spine lock functional. Dorsal fin II,7. Adipose fin with one preadipose plate and fairly long spine. Caudal fin forked, lower lobe longer than upper, I,14,I with four to five (mode four) dorsal procurrent caudal-fin rays and three to five (mode four) ventral procurrent-fin rays. Anal fin short with unbranched ray weak and approximately same length of first branched ray. Anal fin I,4, Pectoral-fin spine almost reaching just beyond pelvic fin when adpressed ventral to pelvic fin. Pectoral fin I,6. Pelvic fin reaching to posterior insertion of anal-fin when adpressed. Pelvic fin I,5.

Iris operculum present. Flap between anterior and posterior nares short. Lips wide, fairly thin. Upper lip with small, round papillae. Lower lip with small papillae anteriorly and posteriorly, becoming larger medially. Maxillary barbel short, maximally reaching base of evertible cheek plates. Buccal papilla small. Jaws narrow, dentaries forming very acute angle, premaxillaries forming angle of 90° to slightly greater than 90°. Teeth with small, moderately wide cusps, lateral cusp approximately half length of medial cusp, stalk of tooth long; seven to 22 dentary teeth (mode 14), six to 22 premaxillary teeth (mode 13).

Color: Base color light tan with brown markings. Head with small to medium spots, spots fading in region between head and dorsal fin. Parieto-supraoccipital crest dark. Body with four dorsal saddles, the first below the middle rays of the dorsal fin, the second below the posterior rays of the dorsal fin and slightly posterior, the third below the adipose fin and slightly anterior, and the fourth at the end of the caudal peduncle. The first two saddles combine at the midline or may fuse completely. Head slightly darker from tip of snout to anterior edge of orbits and medially from posterior edge of frontal to posterior edge of parieto-supraoccipital. All fins with dark bands with dark and light areas of approximately equal width, caudal bands may be irregular. Number of bands increases with size. Dark spot present between dorsal-fin spinelet and spine, and occasionally dark spots present at the bases of the dorsal-fin membranes (darkest anteriorly). Abdomen with medium spots anteriorly and large spots posteriorly. Lower surface of caudal peduncle mottled. Juveniles colored as adults, but with fewer spots on head and few spots (if any) on abdomen.

Sexual Dimorphism: Nuptial males with hypertrophied odontodes on sides and posterior part of head; hypertrophied odontodes becoming larger posteriorly. Hypertrophied odontodes on upper caudal-fin spine and adipose spine. Upper caudal-fin spine thickened. Odontodes on pectoral-fin spine not noticeably larger.

Range: From the Rios Purus, Juruá, Marañon and upper Amazon of Brazil and Peru and also found in the upper Río Madeira of Bolivia ( Fig. 11 ). Two collections from the Río Orinoco basin in Vichada, Colombia appear to be Peckoltia brevis . If it wasn’t for the fact that no other collections of P. brevis have been found north of mainstem Amazon/Marañon and lower Caquetá, and if the range was not bisected by the range of P. lineola , I would not hesitate to call these specimens P. brevis . The specimens are small (48.0– 70.2 mm SL); however, the largest specimen is developing nuptial male odontodes at a size I have not seen before. Certainly more specimens must be found to determine the range of P. brevis . Because of the uncertainty of the identity of the Vichada specimens, I have not included them in the morphometrics or meristics of the species.

Habitat: Specimens collected in Peru were from a lowland, muddy-bottomed river. The specimens were collected on and in submerged logs.

Figures

FIGURE 2. Live pictures of A. Peckoltia bachi, AUM 45592, B. Peckoltia braueri, AUM 38882, C. Peckoltia brevis, D. Peckoltia cavatica, UG/CSBD 11043, holotype, E. Peckoltia lineola, paratype, F. Peckoltia vittata, AUM 39313. Photographs by N.K. Lujan (A) and M.H. Sabaj (B-F).

FIGURE 9. Lateral view of holotype of Hemiancistrus brevis, 86.7 mm SL. Photograph by M. Stiassny.

FIGURE 10. Dorsal, lateral, and ventral views of Peckoltia brevis, INHS 43344, 105.3 mm SL. Photographs by J.W. Armbruster.

FIGURE 11. Distribution of Peckoltia brevis (squares), P.furcata (diamonds), and P. vittata (circles). Open symbols are type localities. Symbols may represent more than one locality.