Tuesday, March 8, 2016

[Ichthyology • 2016] Peckoltia wernekei • A New Species of Peckoltia (Siluriformes, Loricariidae) from the Upper Orinoco River in Amazonas State, Venezuela


Figure 5. Live photos of A Peckoltia lujani (uncataloged), photograph by N.K. Lujan, and
B Peckoltia wernekei sp. n. AUM 39313 (was used as a live photo of P. vittata in Armbruster 2008).
Photograph by M.H. Sabaj Pérez.  DOI:  10.3897/zookeys.569.6630

Abstract
A new species of the suckermouth armored catfish genus Peckoltia is described from the lower Ventuari River, a tributary of the upper Orinoco River in Amazonas State, Venezuela. Specimens of this species were formerly included in the wide-ranging Amazonian species P. vittata, but a recent molecular phylogeny found Orinoco individuals to be distantly related to Amazon Basin individuals spanning the range of P. vittata syntypes. Detailed morphological examination confirmed distinctiveness of Orinoco specimens, and found them to be diagnosable from true P. vittata by having generally greater than 25 teeth (vs. less), spots on the nape (vs. nape lacking spots), the upper lip with two to three black bar-shaped markings in a line like a moustache (vs. lips generally with a hyaline wash), and by the snout having a medial black line disconnected from the moustache markings (vs. medial snout stripe connected to a bar just above the lip). Peckoltia wernekei displays remarkable genetic similarity to its sister species, P. lujani, but differs morphologically by having dentary tooth rows meet at an angle less than 90° (vs. >90°), by having large faint blotches on the abdomen (vs. abdomen with no blotches), by a smaller internares width (21.2–26.6% vs. 28.5–46.5% of interorbital width), and a larger dorsal spine (148.1–178.6% vs. 80.1–134.5% of abdominal length).

Keywords: Ancistrini, Hypostominae, Molecular Phylogeny, Morphology, Peckoltia, Systematics, Taxonomy



Taxonomy

Peckoltia wernekei Armbruster & Lujan, sp. n.
http://zoobank.org/3488FBE3-34F0-4F5B-94D2-60BFA849D945

Peckoltia aff. vittata (Orinoco) Lujan et al., 2015 [molecular phylogeny]


Type locality: Ventuari River drainage, Amazonas State, Venezuela, South America

Holotype: AUM 54314, 104.6 mm SL, VENEZUELA, Amazonas State, Ventuari River drainage, Marujeta Creek, 159 km E of San Fernando de Atabapo, 04.2948°, -066.2889°, N.K. Lujan, M. Sabaj Pérez, D.C. Werneke, T. Carvalho, V. Meza-Vargas, 02 April 2010.

Diagnosis: Peckoltia wernekei can be separated from all other Peckoltia by having a broken black line of pigment on the upper jaw (vs. solid line of pigment along snout edge or snout uniformly colored or mottled). Peckoltia wernekei can be further separated from P. vittata by generally having 25 or more teeth in at least one dentary or one premaxilla (vs. generally 24 or fewer; one specimen of P. wernekei had both upper and lower jaws with <25 teeth/ramus), by having a largely naked abdomen (abdomen with a few plates below pectoral girdle, between pelvic fins and along sides of abdomen; vs. most of ventral surface from the throat to the anus with small plates), and by having large, faint blotches on the abdomen (vs. abdomen uniform). Peckoltia wernekei can be further separated from upper Orinoco congeners as follows: from P. brevis and P. lineola by lacking short lines and spots on the head (vs. lines and spots present), from P. brevis, P. caenosa and P. lineola by having a largely naked abdomen (vs. abdomen fully plated), and by generally having 25 or more teeth per jaw ramus (vs. 22 or fewer in P. brevis, 21 or fewer in P. caenosa, and 19 or fewer in P. lineola); from P. lujani by having the dentaries meet at an angle less than 90° (vs. >90°), by having large, faint blotches on the abdomen (vs. abdomen with no blotches), by a smaller internares width to interorbital width ratio (21.2–26.6% vs. 28.5–46.5%), and a larger dorsal spine to abdominal length ratio (148.1–178.6% vs. 80.1–134.5%); and from P. sabaji by having bands in the dorsal and caudal fins (vs. spots) and prominent dorsal saddles on the body (vs. large spots).


Distribution: Known only from the Ventuari River, a right-bank tributary of the upper Orinoco River in Amazonas State, Venezuela (Fig. 7).

Etymology: Patronym honoring David C. Werneke, Collection Manager of Fishes at the Auburn University Museum, for his diligence, camaraderie and humor during three expeditions to the upper Orinoco Basin and for his long service as a Collection Manager at Auburn University.


Jonathan W. Armbruster and Nathan K. Lujan. 2016. A New Species of Peckoltia from the Upper Orinoco (Siluriformes, Loricariidae). ZooKeys. 569: 105-121. DOI:  10.3897/zookeys.569.6630

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