Cordylancistrus setosus (Boulenger) 1887

Provenzano, Francisco, 2018, Rediscovery of Chaetostomus setosus Boulenger 1887 (Siluriformes, Loricariidae), and assessment of the external characters used for determination of genera within the Chaetostoma group, Zootaxa 4378 (3), pp. 397-413 : 398-403

Cordylancistrus setosus (Boulenger) 1887 new combination

( Figs. 1 , 2 ; Tables 1, 2)

Chaetostomus setosus Boulenger 1887 . Ann. Mag. Nat. Hist., (ser. 5), 19: 348-350. Regan (1904: 239, pl. 12, fig.2) Lasiancistrus setosus Isbrücker (1980:46)

Dolichancistrus setosus Isbrücker (2001:27) , Isbrücker (2002:15), Fisch-Muller (2003:406), Ferraris (2007:235).

Material examined. MBUCV-V-26709, 4 ex (1 C&S), 68.5–98.3 mm SL. Colombia, Departamento del Magdalena, Fundación River, ( The river drain into the Ciénaga Grande de Santa Marta ), near Nabusímake ( San Sebastián de Rábago ), Carlos Ardila , October 1994. CZUT-IC-13896, 1 ex., 92.3 mm SL. Same data as MBUCV- V-26709.

Chaetostomus setosus : BMNH-1880.2.26:9–10, Syntypes, 79.2–95.2 mm LS, Colombia.

Diagnosis. Cordylancistrus setosus lacks a unique distinctive character for accurate identification. It is most similar to C. tayrona and C. daguae . Cordylancistrus setosus is distinguished from its congeners by the combination of the following characters: Length of the pectoral-fin spine tends to be greater, and the orbital diameter tends to be smaller than the other species of Cordylancistrus ( Table 2). Furthermore, C. setosus is distinguished from C. tayrona by the lack of a fleshy keel or excrescence at the posterior tip of the supraoccipital (vs. fleshy keel on supraoccipital present); from C. daguae by a greater interdorsal length (13.9%-15.9% SL vs. 9.2%-13.1% SL) and smaller abdominal length (18.0%-19.1% SL vs. 21.7%–26.1% SL); from C. nephelion , C. perijae and C. pijao by having a depressed body (head depth 15.2%–16.4% SL vs. 16.4–20.2% SL, and caudal peduncle depth 9.0%–9.5% SL vs. 9.5%–14.6% SL); from C. torbesensis and species of Andeancistrus , Chaetostoma and Transancistrus by the presence of a tiny band with very small plates (granules) with odontodes along the snout border (vs. border of the snout naked or completely covered with plates, lacking odontodes); from Andeancistrus platycephalus by the absence of spiny keels on the lateral plates of the body (vs. lateral plates with spiny keels); and from Chaetostoma platyrhynchus by the presence of well-developed and evident evertible cheek odontodes (vs. odontodes vestigial or almost imperceptible). Additionally, C. setosus can be distinguished from all other species in Andeancistrus , Cordylancistrus , and Transancistrus , except for C. torbesensis , C. daguae and C. tayrona , by the presence of hypertrophied, movable cheek odontodes that reach or surpass the pectoral-fin origin (vs. movable cheek odontodes, short, not reaching the pectoral-fin origin). Finally, C. setosus is distinguished from species of Leptoancistrus , by the presence of adipose and anal fins (vs. adipose and anal fins absent). Cordylancistrus setosus resembles species of Dolichancistrus , but does not have one or two bony plates in front of the movable cheek odontodes as in species of Dolichancistrus .

Description. Morphometric data in Tables 1 and 2. Body depressed anteriorly and slightly compressed posteriorly. Dorsal profile of body from tip of the snout through dorsal-fin origin gently convex, straight and sloping downward from dorsal-fin origin to adipose-fin origin, and straight and horizontal to caudal-fin origin. Ventral profile of body flat and straight. Head wide and depressed. Snout covered with small plates, its contour semicircular. Narrow strip with very small plates (granulated) at snout border. Odontodes of different sizes found over this strip. One specimen has large odontodes (hypertrophied) on strip, and probably represents nuptial male. Larger odontodes develop at sides of snout and smaller at center of snout.

Eyes in dorsolateral position, dorsal edge of orbits flat, small odontodes found around orbits. Interorbital space narrow and flat. Supraoccipital flat, without fleshy keel or excrescence. Movable hypertrophied interopercular odontodes well developed, organized as rosette pattern, without one or two bony plates in front of base of odontodes. Specimens have from 12 to 35 movable odontodes; size of odontodes variable, but most posterior one is longest, and surpasses pectoral-fin origin. Opercular bone with an exposed surface, conspicuous externally, its lateral margin with some enlarged odontodes.

Mouth wide and oval in shape. Upper lip edge smooth, without undulations. Lower lip border undulated, and each undulation with other minute undulations. Lips surface papillose. Papillae of anterior lip slightly larger than papillae on posterior lip. Maxillary barbel short and free. Upper and lower jaws wide and almost straight. Teeth numerous and minute. More than 70 teeth in each ramus. Premaxillary teeth slightly larger than dentary teeth. Teeth villiform and asymmetrically bifid, medial cusp longer and wider than lateral cusp. Medial cusp tip rounded, lateral cusp tip pointed. Tooth apex curved toward interior of mouth. Tooth apex yellowish, stalk whitish. Premaxillary and dentary without posterior papillae.

Ventral surface of head and belly naked. Lateral plates posterior to the anus visible, covering ventral surface of body behind anal fin. Anus border undulated. Urogenital papilla present in all specimens, located just posterior to anus, and sometime covered by anus and not visible. Urogenital papilla has two shapes, elongated and tapering in males, and short and wide in females.

Lateral line plates 23 to 24. Post-anal plates 10 to 11. Interdorsal plates six, no keeled plates between dorsal and adipose fins. Origin of dorsal fin anterior to pelvic fin origin. Dorsal-fin spinelet present, small, and sometimes covered with tissue and difficult to see. Dorsal fin with one spine and nine (mode) or eight branched rays, when adpressed reaching the adipose-fin origin. Adipose fin well developed and always present. Adipose-fin spine straight. Pectoral fin with one spine and six branched rays. Pectoral-fin spine almost reaching (in smaller specimens) or surpasses half pelvic-fin spine length when adpressed, longer than longest branched ray. Dorsal and posterior edge of pectoral-fin spine has one row of perpendicular enlarged odontodes, more developed in larger specimens. Also, in larger specimens, the first three branched pectoral-fin rays have row of developed odontodes on dorsal surface, at least proximally. This situation was observed in all specimens, but likely more evident in nuptial males. Pelvic fin with one spine and five branched rays, posterior margin nearly straight, reaching or almost reaching anal-fin origin when adpressed. Third or fourth branched pelvic-fin rays longest. Anal fin with one flexible spine, one unbranched and three branched rays with posterior margin straight, unbranched ray of anal-fin longest. Caudal fin obliquely truncated, lower lobe a little longer than upper lobe. Caudal-fin rays i,14,i.

Maximum size around 115 mm total length (98.3 mm SL), and body more depressed than other species grouped in Cordylancistrus , except C. tayrona .

Color. In ethanol, color pattern of head and dorsolateral surface of body brown with irregularly sized blackish spots randomly arranged, sometimes spots form oblique bands laterally. Belly and ventral surface of head uniformly cream or whitish. Dorsal-fin spine and branched rays with three to five dark bands, interradial membrane hyaline, except for black spot between bases of spine and first branched ray. Pectoral-fin spine with eight or nine dark bands, and branched rays with two to six dark bands. Pelvic-fin spine with five or six dark bands, and branched rays with two to four dark bands. Interradial membrane of pectoral and pelvic fins hyaline. Anal fin whitish. Adipose fin with black oblique band. Caudal-fin spines and branched rays with five or six dark bands. Caudal interradial membrane hyaline.

Geographical distribution. Only known from the upper Fundación River , southwestern slope of Sierra Nevada de Santa Marta, Colombia. The Fundación River drains directly to the Ciénaga Grande de Santa Marta, Caribbean Sea ( Fig.3 ).

Figures

FIGURE 1. Cordylancistrus setosus, MBUCV-V-26709, 98.30 mm SL, male.

FIGURE 2. Chaetostomus setosus, BMNH-1880.2.26:9–10, Syntypes, 95.2–79.2 mm SL, Colombia. Courtesy of Mr. Oliver Crimen, BMNH, UK.

FIGURE3. Map of Colombia showingthe localitiesof Cordylancistrus setosus, (star) C.daguae (square), C. pijao(circle)and C.tayrona (triangles).