Hyphessobrycon brumado, Zanata & Camelier, 2010

Zanata, Angela M. & Camelier, Priscila, 2010, Hyphessobrycon brumado: a new characid fish (Ostariophysi: Characiformes) from the upper rio de Contas drainage, Chapada Diamantina, Bahia, Brazil, Neotropical Ichthyology 8 (4), pp. 771-777 : 772-775

Hyphessobrycon brumado , new species Figs. 1-4

Holotype. MZUSP 101246 (30.7 mm SL, male), Brazil, Bahia, Rio de Contas Municipality, rio Brumado, at Ponte do Coronel , rio de Contas drainage, 13º29’37.0”S 41º52’0.6”W, 1.048 m a.s.l., 8 Feb 2008, A. M. Zanata, P. Camelier, R. Burger & A. B. A. Góes.

Paratypes. All from Brazil, Bahia, Rio de Contas Municipality, rio de Contas drainage, rio Brumado. MZUSP 105730 , 5 , 26.2-30.4 mm SL, UFBA 4341 , 22 , 2 c&s, 25.1-31.6 mm SL, collected with holotype. UFBA 4340 , 13 , 1 c&s, 25.1-26.9 mm SL, above Cachoeira do Fraga , 13º35’54.0”S 41º49’44.0”W, 971 m a.s.l., 8 Feb 2008, A. M. Zanata, P. Camelier, R. Burger & A. B. A. Góes .

Diagnosis. Hyphessobrycon brumado can be distinguished from its congeners, mainly from other Hyphessobrycon species from northeastern Brazilian drainages ( H. bifasciatus , H. iheringi , H. itaparicensis , H. latus , H. micropterus , H. negodagua , H. parvellus , H. piabinhas , H. santae , and H. vinaceus ) by the presence of a broad black stripe along lateral of body that extends through median caudal-fin rays (vs. absence of broad stripe and/or median caudal-fin rays hyaline in all species cited above except H. vinaceus ) and absence of humeral spot (vs. presence in H. bifasciatus , H. itaparicensis , H. micropterus , H. santae , and H. vinaceus ). Hyphessobrycon brumado can be further distinguished from H. bifasciatus by its lower number of branched anal-fin rays (14-17 vs. 25-32) and absence of v-shaped dark lines on body (vs. presence), from H. iheringi by having one maxillary tooth (one specimen with zero and one specimen with two) (vs. two teeth), and from H. itaparicensis by its lower number of branched anal-fin rays (14-17 vs. 20-26), lower body depth (26.8-30.8% vs. 34.1-41.9% of SL), longer caudal peduncle (15.4-18.6% vs. 7.8-12.1% of SL), shorter head length (21.2-24.0% vs. 25.1-30.7% of SL), shorter pelvic fin (12.0-14.6% vs. 15.2-19.8% of SL), and orangeto reddish life coloration (vs. yellowish life coloration). Hyphessobrycon brumado further differs from H. micropterus in the lack of a dark blotch on the dorsal fin (vs. dark blotch present) and from H. negodagua in the presence of an adipose fin (vs. usually absent; 4 of 158 with adipose fin according to Lima & Gerhard, 2001), lower body depth (26.8-30.8% vs. 29.7- 36.6% of SL), relatively lower caudal peduncle depth (26.8- 30.8% vs. 29.7-36.6% of SL), and overall body coloration clearer, without heavy pigmentation of dark chromatophores over dorsum and posterior portion of body. It further differs from H. parvellus by a series of characters, including more scales on the lateral series (33-34 vs. 30-32), lower body depth (26.8-30.8% vs. 32.4-36.9% of SL), shorter distance between snout and pectoral-fin origin (22.3-26.2% vs. 26.8-32.4% of SL), longer caudal peduncle (15.4-18.6% vs. 10.3-14.5% of SL), shorter analfin base (21.3-26.1% vs. 25.0-32.2% of SL), shorter anal-fin lobe length (15.1-18.1% vs. 18.1-24.8% of SL), shorter head length (21.2-24.0% vs. 24.4-31.9% of SL), and distinct overall coloration. Hyphessobrycon brumado can be further distinguished from H. santae by having one maxillary tooth (one specimen with zero and one specimen with two (vs. 3-5 teeth) and from H. vinaceus by having 5-9 perforated lateral line scales (vs. 10-26).

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Description. Morphometric data for the holotype and paratypes given in Table 1. Body elongated. Greatest body depth approximately at vertical through pelvic-fin origin. Dorsal profile of head convex from upper lip to vertical through anterior nostrils; straight to slightly convex from latter point to tip of supraoccipital spine and slightly convex from this point to dorsal-fin origin. Body profile straight to somewhat convex along dorsal-fin base; straight from terminus of dorsalfin base to adipose fin; slightly concave between latter point to origin of anteriormost dorsal procurrent caudal-fin ray. Ventral profile of head and body convex from tip of lower lip to anal-fin origin. Body profile along anal-fin base straight and posterodorsally inclined. Ventral profile of caudal peduncle nearly straight to slightly concave.

Head rounded anteriorly in lateral profile; jaws equal in length anteriorly, mouth terminal. Posterior terminus of maxilla barely reaching anterior margin of orbit. Premaxillary with two rows of somewhat narrow teeth, arranged in a gentle archs facing mouth cavity; outer row with 2(2), 3*(27), or 4(1) teeth, bearing 3 cusps; inner row with 4(1) or 5*(29) teeth bearing 2, 3 or 5 cusps; symphyseal and three first teeth of inner series asymmetrical or not, if asymmetrical with one cusp on anteromedial side, one larger central cusp and 2 smaller on lateral side; posterior teeth with 3 cusps. Maxilla with 0(1), 1*(28), or 2(1) teeth, bearing one or 3 cusps. Dentary with 4 or 5(3) larger and narrow teeth, somewhat anteriorly projected and arranged on a relatively straight line, with 3 or 4 cusps; symphyseal teeth usually with 3 cusps; 5 to 7 diminute teeth with one or 3 cusps follow anterior large teeth, forming straight longitudinal series positioned slightly inner to border of last larger anterior teeth ( Fig. 4 ). First gill arch with 6(3) + 1(3) + 9(2), or 10(1) rakers.

Scales cycloid; circuli absent on posterior margin of scales; none or few slightly poorly developed radii extending to posterior margin of scales. Lateral line incomplete, with 5(1), 6(2), 7(7), 8(10), or 9*(1) perforated 774 A new characid fish from the upper rio de Contas drainage, Bahia, Brazil scales and 33*(15) or 34(6) scales on longitudinal series. Horizontal scale rows between dorsal-fin origin and pelvicfin insertion 8(3), 9*(11), or 10(13). Scales along middorsal line between tip of supraoccipital process and origin of dorsal fin 9(1), 10*(15), 11(8), or disorganized (3). Horizontal scale rows around caudal peduncle 13(1) or 14*(18). Base of anteriormost anal-fin rays covered by a series of 3-5 scales. Caudal fin not scaled.

Dorsal-fin rays ii,7,ii(10) or ii,8,i*(20); distal margin of dorsal fin straight or slightly rounded. Dorsal-fin origin at or slightly posterior to middle of standard length and insertion of last dorsal-fin ray posterior to anal-fin origin; first dorsal-fin pterygiophore inserting behind neural spine of 10 th (2) or 11 th (1) vertebra. Adipose fin present. Anal-fin rays iii,15(3), iii,16(3), iii,17(1), iv,14(1), iv,15(9), iv,16*(12), or iv,17(1); distal margin of anal fin slightly concave; first analfin pterygiophore inserting behind haemal spine of 15 th (2) or 16 th (1) vertebra. Pectoral-fin rays i, 9(8), 10*(17), or 11(5); tip of pectoral fin not reaching vertical through pelvic-fin insertion. Pelvic-fin rays i, 6*(28) or 7(1). Principal caudalfin rays 10+9(3); caudal fin forked, lobes rounded, of similar size. Ten (2) dorsal procurrent caudal-fin rays, and 8(1) or 9(1) ventral procurrent caudal-fin rays. Vertebrae 32(2) or 35(1). Supraneurals 4(1) or 5(2).

Color in alcohol. Overall ground color yellowish ( Figs. 1 and 3 ). Dark chromatophores densely concentrated on dorsal surface of head from upper lip to supraoccipital spine. Infraorbitals and opercle retaining guanine, clear on most of its area, with few relatively large dark chromatophores over area close to orbit and posterior to dorsal portion of eye. Small, dark chromatophores present over anterior half to two-thirds of maxilla. Ventral portion of head less pigmented than dorsal portion; lower lip darkened and portion of head anterior to orbit with scattered dark chromatophores, more concentrated on its median area.

Scales of dorsal portion of body with dark chromatophores, more concentrated along its posterior margin resulting in mild reticulate pattern; reticulate pattern restricted to scales dorsal body half. Humeral region without humeral spot. Dark and relatively broad stripe extends from rear of eye to caudal peduncle; stripe more evident posterior to humeral region and enlarged at end of caudal peduncle, forming rough rounded caudal blotch. Males somewhat darker on posterior portion of body and with caudal blotch more inconspicuous than in females. Caudal blotch extending to median caudal-fin rays, reaching up to12 rays in males and 6-7 in females. Abdominal region without dark chromatophores.

All fin-rays slightly darkened by presence of dark chromatophores scattered over borders of rays and interradial membranes. Pelvic fin somewhat clearer. Caudal fin somewhat darker, with dark chromatophores on distal portion of rays, mainly on central rays, more evident on mature males. Adipose fin slightly darkened by small dark chromatophores.

Color just after fixation. Overall body coloration orange- to reddish ( Fig. 2 ). Borders of scales on dorsal half of body darkened, forming mild reticulate pattern. Dark, elongated and relatively broad stripe extends from vertical around posterior half of anal fin to median caudal-fin rays; stripe enlarged at end of caudal peduncle, forming roughly rounded caudal blotch. All fins orange- to reddish with scattered dark chromatophores and borders relatively clearer. Males apparently more colored than females.

Sexual dimorphism. The unique dimorphic feature observed externally is related to color pattern. Some males have the lateral stripe broader, the blotch on caudal peduncle with inconspicuous border, and a large number of median caudalfin rays darkened (up to 12) ( Fig. 2 ). Females possess a narrower lateral stripe, a more conspicuous rounded caudal blotch and

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dark pigmentation of caudal fin usually restricted to six or seven median rays ( Fig. 3 ). These dimorphic traits are not conspicuous in the majority of specimens examined and are much less evident than the dimorphic coloration described for Hyphessobrycon negodagua (Lima & Gerhard, 2001: figs. 2-3).

Geographic distribution and ecological notes. Hyphessobrycon brumado is known from rio Brumado, tributary of the rio de Contas, a coastal drainage of eastern Brazil ( Fig. 5 ). The species was captured in streams characterized by relatively rapid water current, running over rocky and sandy bottoms at elevate altitudes (971 and 1.048 m a.s.l.) ( Fig. 6 ). The riparian vegetation is formed by grass, shrubs and trees. Fish species collected with H. brumado are Astyanax aff. lacustris , Gymnotus aff. carapo , Hypostomus sp. , Parotocinclus jimi , Poecilia reticulata , Rhamdia aff. quelen , and Trichomycterus sp.

The analysis of stomach contents of three specimens revealed presence of filamentous algae, fragments of vascular plants, adults and two distinct larvae of Diptera ( Chironomidae and Simuliidae ), larvae of Trichoptera, adult of Formicidae, Aranae , and fragments of unidentified arthropods. Presence of allochthonous arthropods and other autochthonous items suggests that Hyphessobrycon brumado is an omnivorous species with a considerable plasticity on its diet. The broad range of food items of this species diet also suggests that it explores the resources available along the entire water column.

Popular name. Piaba.

Etymology. Named after Brumado, the river where the species is found. A noun in apposition.

Figures

Fig. 1. Hyphessobrycon brumado, holotype, male, MZUSP 101246, 30.7 mm SL, Brazil, Bahia, Rio de Contas Municipality, rio Brumado, at Ponte do Coronel, rio de Contas drainage.

Fig. 2. Hyphessobrycon brumado, paratype, just after fixation, male, UFBA 4341, 29.6 mm SL.

Fig. 3. Hyphessobrycon brumado, paratype, female, UFBA 4341, 29.2 mm SL.

Fig. 4. Hyphessobrycon brumado, paratype, UFBA 4341, 26.0 mm SL; scanning electron micrographs (SEM) showing left premaxillary (top) and dentary teeth (bottom) in mesial view. Scale bar = 100 µm. Maxilla without teeth in this specimen.

Fig. 5. Portion of northeastern Brazil, showing position of type locality of Hyphessobrycon brumado (black dot), rio Brumado, rio de Contas drainage.

Fig. 6. Type locality of Hyphessobrycon brumado, Brazil, Bahia, Rio de Contas Municipality, rio de Contas drainage, rio Brumado, at Ponte do Coronel.