Hypostomus kopeyaka, Carvalho & Lima & Zawadzki, 2010

Carvalho, Pedro Hollanda, Lima, Flávio C. T. & Zawadzki, Cláudio H., 2010, Two new species of the Hypostomus cochliodon group (Siluriformes: Loricariidae) from the rio Negro basin in Brazil, Neotropical Ichthyology 8 (1), pp. 39-48 : 40-44

Hypostomus kopeyaka , new species

Figs. 1-2

Hypostomus sp. : Cabalzar et al., 2005: 101, 224 ( Brazil, Amazonas, upper rio Tiquié: short description, ecological notes, horizontal distribution along the rio Tiquié).

Holotype. MZUSP 98764, 226.1 mm SL, Brazil, State of Amazonas , rio Tiquié, Serra do Mucura village, 0 o 10’N 69 o 07’W, 30 Aug - 12 Sep 2006, F. C. T. Lima.

Paratypes. All from Brazil, State of Amazonas , rio Negro basin: MZUSP 92186 , 1, 155.2 mm SL, igarapé Castanha , tributary of rio Tiquié , sand beach on Santa Rosa village , 0 o 04’41”N 69 o 41’26”W, 3-4 Oct 2006, F. C. T. Lima. MZUSP 92485 , 1, 188.3 mm SL, igarapé Castanha , tributary to rio Tiquié , São Lourenço village , 0 o 08’34”N 69 o 36’31”W, 2 Sep 2006, F. C. T. Lima. MZUSP 93074 , 1, 157.8 mm SL, igarapé Castanha , tributary to rio Tiquié, surroundings of Sítio São Pedro, 0 o 11’N 69 o 35’W, 14-30 Nov 2006, F. C. T. Lima .

Additional material (non-types). All from Brazil, State of Amazonas , rio Negro basin: MZUSP 64362 , 1, 112.1 mm SL, igarapé Umari Norte , tributary to rio Tiquié , São Pedro village , 0 o 15’41”N 69 o 57’23”W, 25-27 Oct 2000, F. C. T. Lima et al. MZUSP 81151 , 1, 123.8 mm SL, c&s, rio Tiquié , between Caruru and Boca de Sal villages, 0 o 16’N 69 o 54’W, 2001-2002, M. C. Lopes et al. MZUSP 81500 , 1, 138.2 mm SL, rio Tiquié , São Pedro village , 0 o 16’04”N 69 o 28’51”W, 2001-2002, A. A. Barbosa. MZUSP 81522 , 1, 164.2 mm SL, rio Tiquié , Caruru village , pool below the waterfall, 0 o 16’29”N 69 o 54’54”W, 21-22 Oct 2002, F. C. T. Lima et al. MZUSP 92181 , 1, 166.3 mm SL and NUP 8019 , 1, 140.4 mm SL, igarapé Castanha, tributary of rio Tiquié , sand beach at Santa Rosa village , 0 o 04’41”N 69 o 41’26”W, 3-4 Oct 2006, F. C. T. Lima et al. MZUSP 92330 , 1 , 167.0 mm SL, rio Tiquié , Pirarara-Poço village, 0 o 08’N 69 o 12’W, 6-14 Sep 2006, F. C. T. Lima, M. C. Lopes et al. MZUSP 93012 , 1 , 27.4 mm SL, igarapé Castanha, tributary to rio Tiquié, Santa Rosa indian village, 0 o 04’N 69 o 41’W, 27-30 Nov 2006, F. C. T. Lima et al .

Diagnosis. Hypostomus kopeyaka is distinguished from all Hypostomus species , except those belonging to the Hypostomus cochliodon group, by having few teeth (10 to 13) bearing a small lateral cusp and acutely angled dentaries. It is distinguished from the remaining members of the Hypostomus cochliodon group, except H. hemicochliodon , H. sculpodon , H. soniae Hollanda, Carvalho & Weber , and H. weberi , by possessing bicuspid teeth with mesial cusp rounded, considerably larger than outer cusp (vs. teeth generally unicuspid, outer cusp, if present, almost imperceptible, mesial cusp large and distinctly spoon-shaped). Hypostomus kopeyaka can be distinguished from H. hemicochliodon , H. sculpodon , H. soniae , and H. weberi by a distinctive color pattern composed of conspicuously horizontally elongated, closely-set black spots on the head and dorsal surfaces of the body (vs. spots absent in H. soniae , spots present but rounded in the remaining species, spots small in H. hemicochliodon and H. sculpodon , and large and widely-set in H. weberi ). Additionally, it is distinguished from all the members of the Hypostomus cochliodon group, except H. weberi , H. ericae Hollanda Carvalho & Weber , H. hemicochliodon , H. paucipunctatus Hollanda Carvalho & Weber , H. sculpodon and H. waiampi Hollanda Carvalho & Weber , by possessing a buccal papilla. See the Discussion, for additional remarks on the diagnosis of Hypostomus kopeyaka .

Description. Meristic and morphometric data in Table 1. Overall view of body in Figs. 1 and 2 . Dorsal profile slightly convex to straight from snout tip to interorbital area, convex from interorbital area to dorsal-fin origin, and almost straight from dorsal-fin origin to end of adipose fin. Ventral profile almost straight from snout tip to caudal fin. Caudal peduncle laterally compressed, roughly ovoid in cross section. Body width at cleithral region greater than head depth. Head broad and deep, covered dorsally with plates, except for naked area on snout tip. Median elongated bulge associated with mesethmoid terminating coequally with transversal through nares. Supraoccipital bone with conspicuous moderately to highly developed median ridge, and with relatively welldeveloped posterior process bordered by wide nuchal plate. A conspicuous ridge originating laterally to the nares, passing through supraorbital, and extending to posterior portion of pterotic-supracleithrum. Opercle small, with odontodes more developed distally. Oral disk round, medium-sized, lower lip not reaching transversal through gill openings, ventral surface covered with numerous small papillae decreasing in size posteriorly. Maxillary barbels moderately developed, about as long as orbital diameter. Horizontal patch of odontodes present over anterior surface of upper lip, just below the snout. Buccal papilla well-developed, its tip usually with granular surface. Jaws acutely angled, averaging less than 80 o between left and right dentaries rami. Eight to 16 (mode 14, holotype 16) teeth in premaxilla, seven to 14 (mode 12, holotype 14) in dentary. Teeth bicuspid, curved inward distally, mesial cusp considerably larger than lateral cusp, rounded in shape (similar to the condition found in Hypostomus soniae , Hollanda- Carvalho & Weber, 2004: fig. 4d, and H. hemicochliodon, Armbruster, 2003 : fig. 1B).

Body covered with five rows of moderately spinulose dermal plates. Tip of snout mostly naked even in large specimens, bearing two lateral vertical patches of odontodes. Dorsal-fin base naked. Predorsal region with two conspicuous keels, area between keels flat. Dorsal series of lateral plates with keel from first to third plate, displaced downward from fourth plate onwards, and extending to sixteenth to eighteenth dorsal plate. Mid-dorsal series of lateral plates with keel from first to third plate, slightly displaced downward from fourth plate onwards, and extending to 24 th to 27 th mid-dorsal plate. Median series of plates with moderately-developed keel and bearing lateral line. Mid-ventral series of plates with keel more developed from the first to the fifth or sixth plate. Ventral series of plates with weakly-developed keel along corner of ventral and lateral surfaces, deflecting laterally in the latter 5 to 6 plates. Ventral surface of head covered with platelets, with exception to the region around lower lip. Abdomen completely covered with minute platelets in specimens larger than 150 mm SL, with exception of small areas around pectoral- and pelvic-fin insertions and at urogenital opening. Preanal plate present, exposed in all specimens except MZUSP 64362 (112.1 mm SL). Twenty-four to 25 (mode 24) dorsal plates, 26 to 29 (mode 27) mid-dorsal plates, 27 to 28 (mode 28) median plates, 28 to 29 (mode 28) mid-ventral plates, 22 to 24 (mode 23) ventral plates. Three predorsal plates, eight to nine plates below dorsal fin (mode 8), seven to eight preadipose plates (mode 8), seven to eight plates between adipose fin and caudal fin (mode 8), 14 to 15 plates between anal fin and caudal fin (mode 14).

Dorsal-fin II,7, its origin at vertical through midpoint between pectoral and pelvic fins, or slightly posterior to that point. Dorsal-fin margin convex.Adipose-fin spine compressed and curved inward. Pectoral fin I,6, its posterior border straight. Pectoral-fin spine slightly curved inward, covered with weakly developed odontodes, a little more developed on its distal portion in larger specimens. Tip of adpressed pectoral fin reaching one-third pelvic-fin spine length. Pelvic-fin i,5, its posterior border straight to slightly roundish. Pelvic-fin spine just surpassing anal-fin origin when adpressed. Anal fin i,4, its tip reaching the sixth or seventh plate after its origin. Rays of anal fin progressively increasing in size, third branched ray usually the longer. Caudal-fin margin concave, i,14,i, with inferior lobe longer than superior one.

Color in alcohol. Color description based only on type series. Overall ground color of body and fins beige. Overall ground of ventral area lighter, cream colored in some specimens. Dorsal surface of head and body entirely covered by numerous thin, horizontally elongated, closely-set black spots, smaller and more rounded on head and larger and more elongated along body. These spots occasionally coalesce at midbody, forming narrow, short stripes. Darks spots posteriorly becoming faded and less elongated. Ventral surface of body, from immediately posterior to oral disk to urogenital opening with numerous, small, rounded dark blotches. Ventral blotches coalescing into wavy stripes in abdominal area of one paratype (MZUSP 93074). Overall ground color of fin rays beige, interradial membranes translucent. Dorsal-, pectoral-, and pelvic- fins with rounded, small dark blotches, arranged in rows along interradial membranes. Dorsal-, pectoral-, and pelvic- fin spines each with series of relatively faded dark blotches. Anal fin with faded, rounded blotches along interradial membranes. Faded blotches along adipose-fin spine. Caudal fin displaying several vertical rows of faded dark blotches.

Variation. Specimens listed above as non-types exhibit overall ground color dark-brown to chestnut, instead of the beige color pattern present in the type series (compare Figs. 1 and 2 ). Also, these specimens possess dark blotches larger and less numerous when compared to lighter-colored specimens, and ventral blotches larger and often coalescing into wavy stripes. These specimens were thus considered non-types, although no differences in morphometric or meristic features were found between the lighter, typical specimens and nontypical, darker specimens.

Distribution. Hypostomus kopeyaka is known only from the rio Tiquié basin, a tributary of the rio Uaupés, upper rio Negro drainage, Brazil ( Fig. 4 ). According to Tuyuka fishermen, the species also occurs at the upper rio Tiquié into Departamento Vaupés in Colombia, but no specimens are available from the latter area.

Ecological notes. Hypostomus kopeyaka was collected in rapids, cataract pools, and slow-flowing portions of the rio Tiquié and some large tributaries (igarapé Umari Norte, and igarapé Castanha). No clear habitat preference was identified, though most specimens were collected in relatively slowflowing portions of the rio Tiquié itself or at its large whitewater tributary, the igarapé Castanha.

Etymology. After its common name among the Tuyuka and Tukano indians, kope yaka, or kope ya’ka, meaning “pleco from the holes”, an allusion to the fact that, according to the Indians, the fishes spend most of their time hiding in holes in the river banks (Cabalzar et al., 2005).

Figures

Fig. 1. Hypostomus kopeyaka, holotype, MZUSP 98764, 226.1 mm SL: dorsal, lateral, and ventral views.

Fig. 2. Hypostomus kopeyaka, MZUSP 92330, 167.0 mm SL: dorsal, lateral, and ventral views.

Fig. 4. Map of northern SouthAmerica, showing distributions of Hypostomus kopeyaka (squares) and Hypostomus weberi (dots). Black symbols refer to type-localities.