Peckoltia bachi

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 : 7-13

Peckoltia bachi

( Figs. 2a and 3–4 )

Hemiancistrus arenarius Eigenmann & Allen, 1942: 185 , pl. 6 (fig. 2). Type locality: Yurimaguas. Holotype: CAS

77323. Chaetostomus bachi Boulenger, 1898: 425 , pl. 41 (fig. 1). Type locality: Rio Jurua , an affluent of the Amazons, Brazil .

Holotype: BMNH 1897.12 .1.61. Peckoltichthys filicaudatus Miranda Ribeiro, 1917: 49. Type locality: Fluvio Solimes [ Brazil] . Holotype: MNRJ 969 . Hemiancistrus ucayalensis Fowler, 1940: 235 , figs. 24–25. Type locality: Ucayali River, Contamana , Peru . Holotype:

ANSP 68651.

Material examined: All collections Río Amazonas drainage (except ICNMNH 7955): BRAZIL, Unknown state: BMNH 1897.12 .1.61, Holotype, 1, 95.0, Rio Juruá ; MNHN A-1968, 1, 78.2, Río Amazonas, col. by Jobert ; MNRJ 969 , Holotype of Peckoltia filicaudata , 1, 97.6, Rio Solimões, col. by Alt. Machado da Silva. BRAZIL, Acre : MCP 35511, 1 , Riozinho do Rola, tributary to Rio Acre, itself a tributary to Rio Purus , Rio Branco , 10°02’50”S, 068°18’39”W, L. Juno, 22–23 June 2003 ; MZUSP 50506 , 1 , Foz do Caipora, Rio Juruá , Coleção Reserva Extrativista Alto Juruá, 19 July 1994 ; MZUSP 50507 , 1 , Foz do Tejo, Rio Juruá , Coleção Reserva Extrativista Alto Juruá, 15 July 1994 . BRAZIL, Amazonas : MCP 33228, 1 , 93.8 , Praia Caborini, confluence with Rios Solimões and Japurá , 03°09’34”S, 064°46’35”, col. by W. Crampton, 12 February 2001 ; MZUSP 24611 , 1 , Rio Purus , Açaituba, col. by P.E. Vanzolini, 26 December 1974 ; MZUSP 56113 , 1 , Rio Solimões, 29.6 km below the Juruá , 02°35’55”S, 065°30’57”W, col. by J.P. Sullivan et al., 5 November 1993 ; MZUSP 56282 , 1 , Rio Juruá , 10.2 km below Lago Pauapixuna, 02°41’07”S, 065°48’27”W, col. by J.P. Sullivan et al., 7 November 1993 ; MZUSP 57950 , 1 , Rio Purus , 13 km below Lago do Estopa, col. by Langeani et al., 27 July 1996 ; MZUSP 74235 , 1 , Beach of Rio Solimões, at Ilha Muratu , in front of the mouth of Lago Januacá, col. by Alpha Helix Expedition, 6–25 January 1977 .

COLOMBIA, Amazonas : ICNMNH 2584 , Grammalote, L.F. Jimenez, July 1992 ; ICNMNH 9101 , Puerto Nariño, Laguna Loreto Yacu, P. Cala, January 1972 . COLOMBIA, Meta, ICNMNH 7955 , Río Meta – Río Orinoco Drainage, Quebrada La Quinchalera , Rio Upia basin, San Luis de Gacero . COLOMBIA, Putumayo, Puerto Leguizamo, Río Caquetá basin, collected by Proyecto Ornamentales del Amazonas, October 2005 .

ECUADOR, Napo: FMNH 103265 , 1 , 92.4 , Rio Napo at Destacamento Tiputini , 00°47'S, 075°33'00"W, col. by D. Stewart, M. Ibarra, and R. Barriga, 28 October 1981 ; FMNH 103266 , 1 , 85.7 , Rio Aguarico at Destacamento Zancudo and mouth of quebrada Zancudococha, Río Napo Basin , 00°33'S, 075°30'W, col. by D. Stewart, M. Ibarra, and R. Barriga, 26 October 1983 .

PERU, Amazonas: ANSP 68652, Paratypes of Peckoltia ucayalensis , 2, Río Ucayali basin near Contamana, col. by W.C. Morrow, July 1937; LACM 36318–2, 3, 1 cs, 82.5–98.3, La Poza, stream 1 km N, Río Marañon basin, col. by T. Justice, 12 October 1979; LACM 36325–1, 4, 1 cs, 89.7–100.6, La Poza. stream 1 km N, Río Marañon basin, col. by T. Justice, 18 October 1979; LACM 41906–3, 1, 93.2, Caterpiza, Río Marañon basin, col. by M.P. Achamposh, 25 July 1979. PERU, Loreto: AUM 29578, 1, 81.2, Caño Saccarita, probably ca. 35 min. upstream by boat from the mouth of Tonche Caño, 03°36’50”S, 072°10’55”W, col. by D.M. Schleser, 1 June 1999; CAS 77323, Holotype of P. arenaria , and CAS 77324, Paratype of P. arenaria , Río Huallaga, Yurimaguas, col. by W. R. Allen, November 1920; Río Huallaga, Yurimaguas, col. by W. R. Allen, November 1920; CAS 77325, Paratype of P. arenaria , Río Alto Marañon below Pastaza, col. by W. R. Allen, October 1920; CAS 77326, Paratype of P. arenaria , Río Amazonas, Iquitos, col. by W. R. Allen, September 1920; INHS 39970, 1, 108.4, Río Itaya ca. 4–5 km upstream from Iquitos (Belém), above mouth of Quebrada Mazana, 03°47’71”S, 073°17’29”W, col. by B.M. Burr, M.H. Sabaj, J.W. Armbruster, M. Hardman, R.L. Powell, and R.E. Weitzell, 8 August 1996; INHS 40010, 1, 72.0, Caño Zapatilla ca. 10 min. upstream by boat from Río Orosa, 76.4 mi E Iquitos, 03°32’47”S, 072°09’22”W, col. by M.H. Sabaj, J.W. Armbruster, M. Hardman, and F. Rios Tuluvea, 14 August 1996; INHS 44127, 1, 69.1, Río Napo and creek at Mazan, 33.3 km NE Iquitos, 03°29’33”S, 073°05’12”W, col. by M.H. Sabaj, J.W. Armbruster, M.W. Littman, 2 August 1997; SIUC 29317, 1, 98.5, Río Napo at Mazan, 33.3 km NE Iquitos, 03°29’33”S, 73°05’12”W, col. by M.W. Littman, M.H. Sabaj, and J.W. Armbruster, 1 August 1997; MNRJ 3962, 1, 77.3, Río Ampiyacu near Pebas, col. by W. G. Scherer, 28 February 1940; MNRJ 3963, 1, 77.3, Río Ampiyacú near Pebas, col. by W.G. Scherer; USNM 124885, 1, 104.6, Río Ampiyacu, col. by W. G. Scherer; USNM 329590, 1, 67.2, Maynas Province, Arcadia, Río Napo, quebrada Isla, col. by F. Chang et al., 3 November 1993.

AQUARIUM SPECIMEN: INHS 40916, 1 cs (not measured).

Diagnosis: Peckoltia bachi is diagnosed by one unique characteristic: presence of deep pockets ventrally on the pelvic girdle for the insertion of hypertrophied pelvic adductor muscles. In whole specimens, this results in the ability to fold the pelvic fins ventrally such that the pelvic-fin spines run parallel with the ventral surface body. In addition, P. bachi can be diagnosed by the homoplasic characteristic of the presence of widened pelvic-fin spines.

Peckoltia bachi can be identified from all other Peckoltia by the presence of widened pelvic-fin spines, enlarged plates on the abdomen ( Fig. 4 ), eye low on the head ( Fig. 3–4 ), and opercle generally with a patch of odontodes at all ages (vs. opercle maximally with a single row of odontodes with odontodes disappearing with size). Peckoltia bachi can be identified from all other Peckoltia except P. caenosa by being mottled (vs. the presence of dorsal saddles or spots), and it can be identified from P. caenosa by having diffuse, large spots on the head and the abdomen without markings (vs. head and abdomen with vermiculations).

Description: Morphometrics in Table 1, counts based on 30 individuals unless otherwise stated. Largest specimen examined 108.4 mm SL. Body stout and fairly wide. Head and nape gently sloped to insertion of dorsal fin. Parieto-supraoccipital with slight rounded crest. Dorsal profile sloped ventrally to dorsal procurrent caudal-fin spines, then inclined steeply to caudal fin. Ventral profile flat to caudal fin. Supraorbital ridge rounded, continuing to anterolateral corner of anterior nare. Mesethmoid raised slightly above lateral surface of snout to form slight ridge. Head contours smooth. Eye relatively large, set low on head. Interorbital space slightly convex; supraorbital ridge just slightly higher than interorbital space.

Keels absent. Mid-ventral plates bent at their midline above pectoral fin to form ridge. Dorsal plates bent dorsally below dorsal fin to form very slight ridges that converge at adipose fin, dorsal surface flat between ridges. Five rows of plates on caudal peduncle. Abdomen almost completely plated with fairly large platelets; fairly large naked area around insertion of pelvic 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. 23–27 (mode 24) plates in the median series.

Frontal, infraorbitals, nasal, compound pterotic, sphenotic, and parieto-supraoccipital, supporting odontodes; opercle usually supporting odontodes although some specimens lack odontodes on opercle. Posterodorsal corner of opercle covered by one or two plates in adults. Odontodes on lateral plates not enlarged to form keels. Hypertrophied cheek odontodes 11–44, longest reaching anterior border of compound pterotic. Cheek plates evertible to approximately 90° from head.

Odontodes on tip of pectoral-fin spine slightly hypertrophied. Dorsal fin reaching preadipose plate when adpressed in some specimens; dorsal-fin spine not elongate. Dorsal-fin spinelet V -shaped, dorsal-fin spine lock functional. Dorsal fin II,7. Adipose fin with one preadipose plate and moderately long spine. Caudal fin emarginate, lower lobe longer than upper, I,14,I (one specimen I,13,I and one specimen with caudal peduncle damage I,17,I) with three to six (N=29, mode four) dorsal procurrent caudal-fin rays and three to six (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 reaching slightly behind posterior insertion of pelvic fin when adpressed ventral to pelvic fin. Pectoral fin I,6 (one specimen I,5). Pelvic fin reaching to middle of analfin 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 medium-sized papillae anteriorly and smaller ones posteriorly. Maxillary barbel short, not reaching gill opening. Buccal papilla represented only by very small flap, never absent. Jaws narrow, dentaries forming angle just slightly greater than 90°, premaxillaries forming very shallow arc with overall angle less than 135°. Teeth with small, moderately narrow cusps, lateral cusp approximately half-length of medial cusp, stalks of teeth long, dentary and premaxillary teeth about equal in length; 13–25 dentary teeth (mode 22) and 11–22 premaxillary teeth (mode 19).

Color: Base color tan with slightly darker markings on most specimens (one specimen examined with greater contrast). Head with large spots or mottling. Body mottled occasionally with four weak saddles. Dorsal-fin spines and rays with oblong spots; interradial membranes usually unmarked or with slightly darker spots. Pectoral, pelvic, and anal fins with slightly darker spots on spines and rays or unmarked. Caudal fin with dark spots combining to form bands that are wider than the light interspaces; bands darker on lower lobe. Abdomen and lower surface of caudal peduncle slightly lighter than sides.

Sexual Dimorphism: One specimen (presumably male) examined with hypertrophied odontodes on sides of body and posterior part of head. Hypertrophied odontodes becoming larger posteriorly, but lacking on caudal- and adipose-fin spines. No apparent increase in size of pectoral-fin spine odontodes.

Range: Peckoltia bachi can be found throughout the upper Amazon and its tributaries in Brazil, Colombia, Ecuador, and Peru ( Fig. 5 ). One specimen was found from the Río Meta system near Villavicencio, Colombia. Given that no other specimens have been collected in the Orinoco basin, this collection is suspect. Villavicencio has been active in exporting fishes for a long time, and Armbruster (2005) suggested that a collection of Lasiancistrus guacharote (endemic to the Lago Maracaibo basin) collected near Villavicencio was the result of aquarium release. This may also be the case for P.bachi .

Habitat: Peckoltia bachi can be found at the edge of medium to large rivers among submerged twigs and grasses, usually in flow. The specimens I have collected appear to have been chased from the middle depths of submerged grasses and twigs as the seine was not fully on the bottom. This suggests that the hypertrophied pelvic muscles and widened pelvic-fin spines may be used to grasp the grasses and twigs. In morphology, P. bachi is very similar to Hypoptopoma of the Hypoptopomatinae, sharing the eye placed laterally on the head and the pelvic fins that can be adducted underneath the body. Hypoptopoma also will grasp submerged sticks with its pelvic-fins (pers. obs.).

Comments: There are some differences in intensity of pigmentation of specimens of Peckoltia bachi , but there is nothing to suggest that the species needs to be broken up. The types are all very similar, and nothing could be found to differentiate the various populations. Although the morphology of the species is quite different from any other hypostomine, the recognition of a separate genus for P. bachi at this time is without adequate justification. If it were to be recognized as a separate genus, it would be Peckoltichthys .

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 3. Lateral views of types of species assigned to Peckoltia bachi, A. Hemiancistrus arenarius, CAS 77323, holotype, ~80 mm SL; B. Chaetostomus bachi, BMNH 1897.12.1.61, holotype, C. Peckoltichthys filicaudatus, MNRJ 969, holotype, 97.6 mm SL; and D. Peckoltia ucayalensis ANSP 68652, 85.2 mm SL. Photographs by the California Academy of Sciences Department of Ichthyology (A) and J.W. Armbruster (B-D).

FIGURE 4. Dorsal, lateral, and ventral views of Peckoltia bachi, SIUC 29317, 98.5 mm SL. Photographs by J.W. Armbruster.

FIGURE 5. Distribution of Peckoltia bachi (circles) and P. oligospila (diamonds). Open symbols are type localities. Symbols may represent more than one locality.