Jupiaba kurua, Birindelli & Zanata & Sousa & Netto-Ferreira, 2009

Birindelli, José L. O., Zanata, Angela M., Sousa, Leandro M. & Netto-Ferreira, André L., 2009, New species of Jupiaba Zanata (Characiformes: Characidae) from Serra do Cachimbo, with comments on the endemism of upper rio Curuá, rio Xingu basin, Brazil, Neotropical Ichthyology 7 (1), pp. 11-18 : 12-15

Jupiaba kurua , new species

Figs. 1-3

Holotype. MZUSP 98000 (77.7 mm SL), Brazil, Pará, Altamira, rio Curuá, rio Iriri drainage, in cofferdam of PCH (=small hydroelectric dam) Buriti , 8°46’09”S, 54°57’02”W, 21 Oct 2007, J. L. O. Birindelli, L. M. Sousa, A. L. Netto-Ferreira, M. H. Sabaj Pérez & N. Lujan.

Paratypes. All from Brazil, Pará, Altamira, Iriri drainage: ANSP 187419 (5, 63.4-74.8 mm SL), AUM 47568 (2, 66.4-67.1 mm SL), INPA 28857 (2,0 65.1-66.8 mm SL), MNRJ 31913 (2, 64.6-66.0 mm SL), MZUSP 96857 (70, 51.9-86.0 mm SL, 5 cs, 56.4-77.6 mm SL), UFBA 3943 (8, 56.5-77.9 mm SL), collected with holotype. MZUSP 31864 (1, 79.8 mm SL), MZUSP 77566 (1, 30.5 mm SL), rio Curuá , Serra do Cachimbo , 15 Aug 1984, M. Goulding. MZUSP 96939 (1, 58.1 mm SL), rio Curuá , above the falls, 8°44’09”S, 54°57’46”W, 20 Oct 2007, J. L. O. Birindelli et al., MZUSP 97105 (60, 45.9-82.3 mm SL, 1 cs, 69.1 mm SL), rio Curuá , upstream of dam, 8°46’28”S, 54°57’12”W, 21 Oct 2007, J. L. O. Birindelli et al., MZUSP 101299 (16,74.8- 86.6 mm SL), rio Curuá , below dam, 8°44’30”S, 54°57’35”W, 23 Jan 2009, A. L. Netto-Ferreira et al., MZUSP 101306 (1, 74.9 mm SL), rio Curuá , 9°00’40”S, 54°58’17”W, 22 Jan 2009, A. L. Netto-Ferreira et al .

Diagnosis. Jupiaba kurua is distinguished from its congeners, except J. acanthogaster (Eigenmann) , J. atypindi Zanata , J. keithi (Géry, Planquette & LeBail) , J. maroniensis (Géry, Planquette & LeBail) , J. meunieri , J. minor and J. pinnata (Eigenmann) , by the presence of teeth cusps of similar size and dentary teeth gradually decreasing in size posteriorly. The new species differs from the aforementioned congeners, except J. meunieri , by the color pattern that consists of dark dots on the base of the majority of lateral body scales, inconspicuous dark elongated humeral blotch and wellmarked dark round blotch on the caudal peduncle. Jupiaba kurua is further distinguished from J. meunieri (as well as similar species such as J. maroniensis ) by having 5 to 6 scale series between lateral line and pelvic-fin origin (vs. 6.5 to 7.5), 21 to 24 branched anal-fin rays (vs. 25 to 31), body depth at dorsal-fin origin 33.3 to 40.2 %, mean 36.3 % of SL (vs. 42.7 to 47.9 %, mean 45.5 % of SL, based on examined specimens).

Description. Morphometric data of the holotype and paratypes given in Table 1. Body compressed, moderately elongate. Greatest body depth slightly anterior to dorsal-fin origin. Dorsal profile convex from upper lip to vertical through anterior nostrils, straight from latter point to tip of supraoccipital spine, convex from that point to terminus of dorsal-fin base, straight from latter point to adipose fin, and slightly concave between adipose fin to origin of dorsalmost procurrent caudal-fin ray. Ventral profile convex from lower lip to anal-fin origin (in some specimens nearly straight between anterior tips of pelvic-spine and anal-fin origin), straight along anal-fin base, and slightly concave from terminus of anal-fin base to caudal peduncle.

Jaws equal in length, mouth terminal. Posterior terminus of maxilla barely reaching to slightly trespassing vertical through anterior margin of orbit. Teeth somewhat compressed, cusps aligned along distal tooth margin. Premaxillary teeth in two rows ( Fig. 3), four (5) or five (1) pentacuspid teeth on outer row, five (6) teeth bearing seven to nine cusps on inner row; symphyseal tooth of inner series comparatively small, asymmetrical, with lower number of cusps on anteromedial side. Maxilla with two (6) teeth bearing five or seven cusps; anteriormost tooth usually the largest. Nine (4) or ten (2) teeth on dentary; medial teeth with seven or nine cusps, posterior ones tricuspid or conic; symphyseal tooth usually symmetrical, with central cusp slightly larger than remaining cusps. Majority of remaining teeth asymmetrical, with lower number of cusps on medial side of tooth. Dentary teeth gradually decreasing in size and in number of cusps posteriorly.

Scales cycloid, circuli restricted to covered area of scales, with few slightly divergent radii extending to posterior margin of scales. Lateral line slightly curved ventrally, 36 (19), 37* (22), or 38 (1) perforated scales continuous from supracleithrum to base of caudal fin. Longitudinal scale rows between dorsal-fin origin and lateral line six (20) or seven* (22). Longitudinal scale rows between lateral line and pelvicfin origin five (19), 5.5* (20) or six (3). Scales along middorsal line between tip of supraoccipital process and origin of dorsal fin nine (11), ten* (18), 11 (10), or 12 (3). Horizontal scale rows around caudal peduncle 14 (42). Single row of eight to ten scales covering base of anterior most anal-fin rays.

Dorsal-fin rays ii, 9 (42), distal margin of dorsal fin straight to slightly concave. Dorsal-fin origin slightly anterior to middle of standard length, first dorsal-fin pterygiophore inserting posterior to neural spine of nineth (5) vertebra and posterior insertion of dorsal fin slightly anterior to vertical through anal-fin origin. Adipose fin present. Anal-fin rays iv or v, 21 (13), 22* (20), 23 (8), or 24 (1), distal margin of anal fin concave; first anal-fin pterygiophore inserting posterior to haemal spine of 18 th (1) 19 th (4) vertebra. Pectoral-fin rays i, 11 (2), 12 (14), 13* (23) or 14 (2), tip of pectoral fin reaching shy to vertical through pelvic-fin origin. Pelvic-fin rays i, 7 (42); pelvic bone elongate, modified into spine, with anterior portion diverging (in relation to its counterpart) but usually not protruding through body wall. Principal caudal-fin rays 10+9 (42); caudal fin forked, lobes slightly rounded, of similar size. Ten (2) dorsal procurrent caudal-fin rays, and nine (2) ventral procurrent caudal-fin rays. Gill-rakers on first gill arch six (2) or seven (3) on epibranchial, one (5) on cartilage between ceratobranchial and epibranchial, nine (5) on ceratobranchial, and two (5) on hypobranchial. Vertebrae 35 (4) or 36 (1). Supraneurals five (5). Branchiostegal rays four (5).

Color in alcohol. Ground color tan, darker dorsally. Small dark chromatophores densely concentrated on dorsal surface of head from upper lip to supraoccipital spine. Dense pigmentation continuing posteriorly throughout middorsal line of body. Maxilla, infraorbitals, and opercle with scattered dark chromatophores; in some specimens chromatophores more concentrated on region close to orbit or on upper half of opercle. Ventral portion of head less pigmented, with scattered small dark chromatophores from lip to vertical through anterior margin of orbit.

Scales of dorsal portion of body darkened (especially the three to five dorsalmost horizontal series), with small dark chromatophores distributed over entire scales or leaving only small anterocentral portion somewhat pale. Scales from two to three series above and below lateral line with dark chromatophores concentrated on basal portion. Resulting color pattern consisting of five to six lines of spots along lateral of body.Abdominal region yellow, without dark chromatophores.

Humeral region with a poorly-defined blotch, followed by an inconspicuous midlateral stripe relatively wide, formed by small subjacent dark chromatophores; stripe continuous with caudal blotch. Caudal peduncle blotch rounded, not reaching dorsal and ventral borders of caudal peduncle; some specimens with caudal peduncle blotch, extending as a faded stripe onto median caudal-fin rays. Dark chromatophores concentrated along lateral margins of caudal-fin rays.

Dorsal fin with scattered dark pigmentation. Anal fin darkened in similar pattern as dorsal fin, but with chromatophores more concentrated along its distal border, forming inconspicuous dark band. Pectoral and pelvic fins with dark chromatophores distributed along lateral margins of rays. Adipose fin with scattered dark chromatophores.

Color in life. Body and head tending to pale below lateral midline, tan and darker dorsally. Dorsal and adipose fins somewhat orange, pectoral, pelvic, anal, and caudal fins yellow. Anal fin with dark distal band. Eyes black, except for red anterodorsal portion.

Sexual dimorphism. Bony hooks present on pelvic and analfin rays of 15 male specimens. Pelvic-fin hooks distributed on median to distalmost portions of last unbranched and first to seventh branched rays (hooks not fully developed in some specimens).

Geographic distribution. Jupiaba kurua is known from the upper rio Curuá, above the two great falls in Serra do Cachimbo ( Fig. 4). Rio Curuá is a tributary of rio Iriri, the latter a large tributary of lower rio Xingu. Collections made below the waterfalls indicate that the new species may be restricted to the isolated river portion above the falls (see discussion for more details on the endemism of upper rio Curuá).

Ecological notes. The rio Curuá is a clear water river.Analysis of the stomach contents of six cleared and stained paratypes revealed the presence of termites, ants, small wasps, mayfly nymphs, dipteran larvae, chironomid larvae, pupae and adults, caddis fly larvae, characiform scales, fin rays, Podostemaceae fragments, filamentous algae, sediment, unidentified insect fragments and unidentified vegetal fragments. Even though podostemacean fragments and filamentous algae were the main food items on the specimens examined, presence of additional allochthonous insects and other autochthonous items suggests that Jupiaba kurua is an omnivorous species with a considerable plasticity on its diet. The broad range of food items on this species’ diet also suggests that it explores the resources available along the entire water column.

Etymology. From the tupi language kurua , in allusion to the type locality, rio Curuá. A noun in apposition.