Peckoltia caenosa, Armbruster, 2008

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 : 20-23

Peckoltia caenosa new species

( Fig. 12 )

Holotype: MCNG 42665, 135.1 mm SL, VENEZUELA, Portuguesa, Río Orinoco dr.: Caño Maraca, tributary of Caño Igues – Río Portuguesa, Guanare-Guanarito road at road km 60, 08°49’39”N, 069°20’42”W, 17 December 1999, J.W. Armbruster, M. Hardman, J.D. Evans, and J.A. Thomas.

Paratypes: All collections Río Orinoco drainage : ANSP 166749 , 3 , 69.4 – 119.7 , VENEZUELA, Anzoategui , Río Orinoco dr., Soledad, Lago Tineo , 08°11'25"N, 063°28'20"W, 15 April 1986, M. Rodriguez and S. Richardson; VENEZUELA, Apure : MCNG 9721 , 1 , 93.8 , Cao Terecay, 35 Km to the north of the road to Modulos field station, 0750’20”N, 069°19’00” W, 18 March 1981, D.C. Taphorn ; MCNG 37452 , 1 , 123.1 , Río Arauca, in El Yagual , ~ 07°27’31”N, ~ 068°25’24”W, 14 November 1997, Astudillo and Martinez ; MCNG 38972 , 1 , 133.8 , Río Manglar 500 meters from the bridge, D. Arana; VENEZUELA, Cojedes : MCNG 24200 , 1 , 72.6 , Cao Igues, via Arismendi, south of El Baul , 1990. VENEZUELA, Portuguesa : AUM 18946, 4 , 1 cs, 93.4–156.9, same data as holotype ; AUM 22836, 1 , 69.4 and ANSP 180224 , 1 , 134.1 , same locality as holotype, 1 January 2000, J.W. Armbruster, M. Hardman, J.D. Evans, and J.A. Thomas ; UF 32382 , 2 , 81.2 – 94.4 , same locality as holotype, 27 March 1981, C . R. Gilbert and C.G. Lilyestrom .

Nontype (Not included as paratypes because they are faded and difficult to confirm identification): USNM 258213, 1, not measured, VENEUELA, Guarico, Río Orinoco dr., Río Orituco where crossed by road from Calabozo, 27 January 1983, A. Machado et al.; USNM 258215 , 1 , not measured, Apure, main channel of Río Apure in region of San Fernando de Apure, 07°53’N, 067°29’W, 25 January 1983, Technicians of Apure Fisheries .

Diagnosis: Peckoltia caenosa can be identified from all other species of Peckoltia by having dark vermiculations on the abdomen (vs. spots, long, fairly straight, wide lines, or plain); from all except P. bachi by having the dorsal and lateral surface of the body mottled (vs. with spots or saddles); and from P. bachi by having the spots on the head small (vs. large) and generally forming vermiculations (vs. separate), the pelvic spines narrow (vs. wide), and the eye high on the head (vs. low).

Description: Morphometrics in Table 2, counts based on 17 individuals. Largest specimen examined 156.9 mm SL. Body stout and fairly wide. Head gently sloped to parieto-supraoccipital. Parieto-supraoccipital with tall, rounded crest giving head the appearance of stepping to greater depth. 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 relatively small.

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. A pair of lateral plates converging at midline between anus and exposed first anal-fin pterygiophore. 25–27 (mode 26) 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 10–58, 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, not 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 strongly forked, lower lobe longer than upper, I,14,I with four to five (mode five) dorsal procurrent caudal-fin rays and four to five (mode four) ventral procurrent-fin rays. Anal fin short with spine weak and approximately same length of first ray. Anal fin I,4, Pectoral-fin spine almost reaching anus when adpressed ventral to pelvic fin. Pectoral fin I,6 (one anomalous specimen I,8). 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; 10–18 dentary teeth (mode 15), 11–21 premaxillary teeth (mode 17).

Color: Mottled with light and dark brown. Dark spots all generally combining to form vermiculations on dorsal surface of head. Light spots on fin spines and rays, membranes of caudal fin also with light marking so that spots combine to form bands, light bands about 25% width of dark bands. Four dorsal saddles present, slightly darker than surrounding areas: first below anterior portion of dorsal fin, second below posterior portion of dorsal fin and slightly posterior, third below adipose fin and fourth at base of caudal fin. Nasal flap and parieto-supraoccipital crest slightly darker than rest of head. Ventral surface slightly lighter than sides. Abdomen covered with brown spots that combine to form vermiculations. Ventral surface of caudal peduncle with light, wavy stripes. Juveniles colored as adults, but with fewer, relatively larger spots on abdomen, some of which are not combined to form vermiculations.

Sexual dimorphism: None observed.

Range: Found in the llanos of Venezuela in rivers draining into the middle Río Orinoco ( Fig. 8 ).

Habitat: Found in slow-flowing muddy streams. Can be found during the day inside of submerged, hollow logs.

Etymology: From the Latin caenosus meaning muddy or dirty, in reference to the muddy coloration of this species and its preference for muddy habitats.

Figures

FIGURE 8. Distribution of Peckoltia braueri (triangles), P. caenosa (circles), P. cavatica (squares) and P.lineola (diamonds). Open symbols are type localities; the type locality for P. braueri is not adequate to plot on the map. Symbols may represent more than one locality

FIGURE 12. Dorsal, lateral, and ventral views of the holotype of Peckoltia caenosa MCNG 42665, 156.9 mm SL. Photographs by J.W. Armbruster.