Neblinichthys peniculatus, Armbruster & Taphorn, 2013

Armbruster, Jonathan W. & Taphorn, Donald C., 2013, Description of Neblinichthys peniculatus, a new species of loricariid catfish from the río Paragua drainage of Venezuela, Neotropical Ichthyology 11 (1), pp. 65-72 : 67-69

Neblinichthys peniculatus , new species Figs. 2-4 , Table 2

Holotype. MBUCV V-35680, 78.8 mm SL, male, Venezuela, Bolivar, río Paragua drainage, río Carapo at first rapids along right bank, 5°41’51”N 63°32’30”W, 22 Feb 1990, C. J. Ferraris, A. Machado-A. & R. Royero ( Figs. 2 and 3 ).

Paratypes. AMNH 255488 , 2 (1 male, 1 female), 67.5-78.8 mm SL , AMNH 91020 , 71.6 mm SL, female, ( Fig. 4 ) , AUM 56753 , 1 (male), 71.5 mm SL, collected with holotype ; AMNH 91021 , 14 (1 male, 1 female, 1 juvenile, 11 fry), 11.1-81.3 mm SL (3 measured, 60.1-81.3 mm SL) , MBUCV V-35681, 3, 71.5-76.7 (not measured), Venezuela, Bolivar, río Paragua drainage, río Carapo at third rapids above camp along left bank, 5°42’48”N 63°32’00”W, C. J. Ferraris & R. Royero , 28 February 1990 .

Diagnosis. Neblinichthys peniculatus differs from all congeners by having mottling on the caudal peduncle consisting of dark spots and dashes (vs. caudal peduncle all about the same color or light below and dark above; Figs. 2 and 4 ), by having spots on the head (spots less conspicuous in nuptial males as the head is darker; vs. no spots; Figs. 2 and 4 ), and by having hypertrophied snout odontodes smaller than orbit diameter (vs. much larger than orbit diameter; nuptial males unknown for N. yaravi ; see Discussion, Fig. 3 ); from N. brevibracchium and N. echinasus by having an iris operculum (vs. operculum absent or at most dorsal rim of iris straight), by having odontodes on the opercle (vs. usually zero, but no more than one, odontodes on opercle), and internares 3.9-4.6% HL (vs. 5.0- 8.5% in N. brevibracchium and 6.2-6.7% in N. echinasus ), and by having no spots (or at best very faint spots on a light background) on the abdomen of adult males (vs. large light spots and vermiculations on a dark abdomen); from N. pilosus and N. yaravi by having a rectangular dark blotch at the base of the caudal fin (vs. blotch absent; Figs. 2 and 4 ); from N. pilosus by internares width 10.5-12.4% HL (vs. 17.3-20.1%), and postanal length 28.5-30.6% SL (vs. 32.8- 34.9%); from N. roraima by having a one (occasionally two) preadipose plates with the adipose membrane conspicuous (vs. five to nine preadipose plates and the adipose membrane inconspicuous or absent), and greater than 20 evertible cheek odontodes (vs. 10 or fewer); from N. roraima and N. yaravi by having five anal-fin rays (vs. three to four in N. roraima and four, one specimen with five, in N. yaravi ); and from N. yaravi by having large spots on the fins that clearly proceed onto the membranes (vs. small spots only on rays; Figs. 2 and 4 ), four to five bands or rows of spots in the caudal fin (vs. at least seven; Figs. 2 and 4 ), and a larger predorsal length/postanal length ratio (150.1-164.6% vs. 120.1-144.5%).

Description. Morphometrics presented in Table 1. Meristics based on eight individuals. Largest specimen male: 81.3 mm SL.

Body dorsoventrally flattened. Caudal peduncle laterally compressed. Profile from tip of snout to dorsal-fin origin convex. Orbits slightly elevated above head profile. Deepest point of body just anterior to dorsal fin. Profile straight or gently concave to adipose-fin origin, then slightly concave to base of upper caudal-fin spine. Ventral surface flat or slightly concave from just behind oral disk to anal-fin origin then straight to base of lower caudal spine. Eyes widely separated, laterally oriented, not visible from below. Snout broad and rounded. Body widest at pectoral-fin origin, then narrowing gently to origin of pelvic fins, then narrowing more quickly to caudal fin.

Anterior margin and dorsal surface of snout with small odontodes except in nuptial males (see Sexual dimorphism). Cheek plates strongly evertible (to 90° from head), cheek odontodes relatively long and numerous (~45-80), longest reaches to level of pectoral-fin spine insertion. Iris operculum absent, making dorsal rim of pupil round.

Mouth moderate in size with narrow premaxillary and dentary tooth cups forming gentle arcs; dentigerous surfaces of dentary slightly smaller than premaxillary. Premaxillary teeth 49-90; dentary teeth 53-80. Teeth villiform and bicuspid with very short cusps (medial cusp longer than lateral). Edge of oral disk largely smooth, extending to vertical through anterior margin of eye, not extending beyond lateral margins of head. Enlarged central papilla present in buccal cavity. Maxillary barbel short, just reaching base of evertible cheek plates. Ventral surface of lips papillose. Papillae largest in center of lower lip, decreasing radially. No enlarged papillae located behind dentary teeth.

Dorsal fin II,7; exposed portion of dorsal-fin spinelet flat with few, short odontodes. Dorsal fin short, not reaching preadipose plate when adpressed. First dorsal-fin ray slightly longer than dorsal-fin spine. Pectoral fin I,6. Pectoral-fin spine short (about equal to pelvic-fin spine), reaching insertion of first branched pelvic-fin ray when adpressed ventral to pelvic fin; narrow but strong, numerous odontodes of equal size present along entire length in females, but odontodes becoming larger distally in nuptial males. Anterior pectoral-fin rays longer than pectoral-fin spine, decreasing to about half of length of spine posteriorly, covered with odontodes, largest on dorsal surface. Pelvic fin I,5; spine thickened and covered with odontodes, reaching into anterior third of anal-fin base when adpressed; anterior pelvic-fin rays longer than pelvic-fin spine with posterior margin of fin curving out beyond posterior tip of spine. Anal fin I,5; all branched anal-fin rays slightly longer than unbranched ray; unbranched ray with odontodes to about three quarters of its length. First anal-fin pterygiophore not exposed to form plate-like structure. Adipose-fin spine straight to slightly curved posteriorly with adipose membrane extending beyond posterior extent of spine, but some specimens with shortened spine and very small membrane; usually one (two specimens with two) preadipose plates. Caudal fin I,14,I; lower caudal-fin spine slightly longer than upper, edge of caudal fin straight and oblique. Dorsal procurrent caudal-fin rays four or five, ventral procurrent caudal-fin rays three or four. Rays of all fins supporting small odontodes.

Median plate series with 22-24 (mode 23) plates, not counting triangular plates on base of caudal fin. Ventral plates forming gentle arc on caudal peduncle and not forming strong rounded keel. Plates in mid-ventral row weakly arched submedially forming low ridge from cleithrum to posterior insertion of pelvic fin. Three rows of plates on caudal peduncle (mid-dorsal plate series ending at level of adipose fin). Abdomen naked.

Coloration in alcohol. See Figs. 2-4 . Head, dorsum of body and sides tan with irregular, darker brown or black spots and blotches; mottling most intense on caudal peduncle; spots best formed on head, although faded in nuptial males. No individuals with regular rows of spots. Ventrum light colored, whitish or light tan with few faint dark spots on periphery in larger specimens. Oral disk with inner papillated surface pale tan; outer anterior margin of upper lip gray-brown. All fin spines and rays with spots centered on rays, but extending onto membranes. Occasionally, spots on fins combine to form bands with three to four bands in caudal fin (may be regular or irregular) and three to four bands in dorsal fin. Rectangular dark blotch present on base of caudal fin. Dark spot present at base of anteriormost dorsal-fin membrane. Dorsal surface with five saddles, usually faint), first under anterior part of dorsal fin, second under posterior part of dorsal fin, third and fourth very narrow on either side of adipose fin, and fifth dorsal extension of rectangular blotch on base of caudal fin. Eleven juveniles examined (11.1-23.7 mm SL), all brown (lighter ventrally) except for faint saddles, rectangular blotch and two other bands in caudal fin and two bands in dorsal fin.

Sexual Dimorphism. See Figs. 2-3 vs. 4. Males with elongated odontodes on dorsal portion of head and cleithrum anteriorly and ventrally from an arc extending from exposed dorsal part of cleithrum, to exposed opercle, to anterior of eye to nares; odontodes longest just anterior to base of evertible cheek plates, anteriorly above center of snout, and on opercle; longest odontode slightly smaller than orbit diameter. Hypertrophied odontodes also present on opercle, and exposed portion of cleithrum. Snout skin appears to thicken prior to emergence of hypertrophied odontodes as some individuals have thickened skin and shorter odontodes. Size of odontodes in holotype appear to be maximum size (see Discussion). Odontodes on head of female not elongated. Males also have odontodes on pectoral-fin spines becoming longer distally (vs. all about same size in females). Dark spots on head faded in males.

Distribution. Known from the río Carapo, a tributary of the middle río Paragua of Venezuela. The río Carapo drains the southern flank of Cerro Guaiquinima. Based on Google Earth, the first rapids complex on the Carapo is at 5°41’51”N 63°32’30”W, and the specimens were collected from 100m above the lower extent of the rapids as well as a rapids complex further upstream, the third rapids is likely at 5°42’48”N 63°32’00”W.

Etymology. Adjective from the Latin peniculus for brush, if reference to the brushlike odontodes on the snout.

Figures

Fig. 2. Dorsal, lateral, and ventral views of Neblinichthys peniculatus,holotype, male, MBUCVV-35680, 78.8mm SL, Venezuela, Bolivar, río Paragua drainage, río Carapo at first rapids along right bank.

Fig. 3. Dorsal view of head of holotype of Neblinichthys peniculatus,MBUCV V-35680, 78.8 mm SL.

Fig. 4. Dorsal, lateral, and ventral views of Neblinichthys peniculatus, female, paratypes, AMNH 91020, 78.8 mm SL.