Jupiaba citrina, Zanata & Ohara, 2009

Zanata, Angela M. & Ohara, Willian M., 2009, Jupiaba citrina, a new species from rio Aripuanã, rio Madeira basin, Amazonas and Mato Grosso States, Brazil (Characiformes: Characidae), Neotropical Ichthyology 7 (4), pp. 513-518 : 514-518

Jupiaba citrina , new species

Figs. 1-3

Holotype. INPA 32026 , 60.5 mm SL, Brazil, Amazonas, Apuí, rio Madeira basin, middle rio Aripuanã drainage, igarapé on the left margin of the rio Guariba , Reserva Extrativista do Guariba , Mosaico do Apuí , 08°46’31.0”S 60°31’27.7”W, 13 Nov 2008, F. R. V. Ribeiro & T. F. Teixeira.

Paratypes. Brazil, Amazonas State, rio Madeira basin, rio Aripuanã drainage . INPA 32027 , 16 , 47.0- 62.1 mm SL ; MZUSP 101607 , 3 , 56.6-57.1 mm SL, collected with the holotype . INPA 32028 , 10 , 1 c&s, 41.2-101.3 mm SL ; MPEG 15530 , 3 , 56.6-57.1 mm SL, same locality and collectors as the holotype, 11 Nov 2008 . Mato Grosso State, rio Madeira basin, rio Aripuanã drainage . MZUSP 100542 , 3 , 47.8-54.9 mm SL, Aripuanã, rio Aripuanã, Balneário Primavera , below Dardanelos waterfall, 10°10’06”S 059°26’50”W, 03 Apr 2004 , F. A. Machado, C. M. C. Leite, N. E. Silva & N. Flausino Jr. MZUSP 18676 , 2 , 50.3-78.9 mm SL, Igarapé do Porto , 09°58’00”S 059°19’00”W, 16 Nov 1976 , Equipe de Ictiologia / INPA. UFBA 4688 , 2 , 46.8-53.1 mm SL, Colniza, igarapé on Parque Estadual Igarapés do Juruena , 08°57’21.5”S 59°20’48.5”W, 27 May 2008 , I. M. Fernandes & N. Fausino Jr. UFBA 4687 , 3 , 51.2-58.8 mm SL, Colniza, igarapé on Parque Estadual Igarapés do Juruena , 08°58’42.6”S 59°20’48.8”W, 27 May 2008 , I. M. Fernandes & N. Fausino Jr. UFBA 4689 , 1 , 51.0 mm SL, Colniza, igarapé on Parque Estadual Igarapés do Juruena , 09°00’03.3”S 59°14’44.6”W, 30 May 2008 , I. M. Fernandes & N. Fausino Jr.

Non-type material. Brazil, Mato Grosso State, Aripuanã, rio Madeira basin, rio Aripuanã drainage, stream tributary of rio Guariba. NUP 6761, 15, 35.3-50.5 mm SL, 10°06’35”S 59°26’12”W, 18-19 May 2008, I. M. Fernandes. NUP 6764, 2, 42.8-43.2 mm SL, 10°04’47”S 59°31’04”W, 15 May 2008, I. M. Fernandes. NUP 6768, 6, 40.7-47.2 mm SL, 10°03’57”S 59°3’54”W, 15 May 2008, I. M. Fernandes .

Diagnosis. Jupiaba citrina is distinguished from its congeners (except J. abramoides (Eigenmann) , J. anteroides , and J. poranga Zanata ) by its color pattern, consisting of two vertically-elongated humeral blotches, the anterior usually with a darker median portion forming an horizontallyelongated trace pointed anteriorly, and a well defined dark longitudinal line extending from the second humeral blotch to the caudal peduncle. The new species differs from J. abramoides , J. anteroides , and J. poranga by having an horizontally-elongated blotch on caudal peduncle that extends continuously to the distal tip of the caudal-fin median rays (vs. dark line not forming blotch on caudal peduncle and posterior end of this line isolated from dark blotch over caudalfin rays by a clear area). Jupiaba citrina differs from various congeners (except J. abramoides , J. anteroides , J. apenima , J. asymmetrica (Eigenmann) , J. poranga , and J. yarina Zanata ), by having the predorsal median area without a series of scales (vs. predorsal median area with a series of organized scales). Jupiaba citrina differs further from J. poranga and also J. yarina by its lower number of perforated scales (47-51 vs. 56-66) and lower number of scales between dorsal-fin origin and lateral line [10-11 (one specimen with 12) vs. 12-15] and between lateral line and origin of pelvic fin (8-9 vs. 10-13). From J. apenima it differs also by having lower number of perforated scales (47-51 vs. 55-59). The new species can be additionally distinguished from part of its congeners ( J. acanthogaster , J. atypindi Zanata , J. keithi (Géry et al.) , J. maroniensis (Géry et al.) , J. meunieri (Géry et al.) , J. kurua Birindelli et al. , J. minor (Travassos) , J. pinnata (Eigenmann) , and J. poekotero Zanata & Lima ) by having teeth with a distinctly larger median cusp and dentary teeth decreasing abruptly in size posteriorly (vs. median teeth cusp similar in size to the remaining cusps and dentary teeth decreasing gradually in size towards posterior portion). From the remaining species, J. citrina differs further from J. iasy (Netto- Ferreira et al.), J. mucronata (Eigenmann) , J. ocellata (Géry et al.) , J. paranatinga (Netto-Ferreira et al.) , J. pirana Zanata , J. polylepis , J. potaroensis (Eigenmann) , and J. zonata by having higher number of perforated scales (47-51 vs. 33-45), and from J. elassonaktis Pereira & Lucinda , J. essequibensis (Eigenmann) , and J. scologaster (Weitzman & Vari) by having higher number of branched anal-fin rays (24-27 vs. 17-23).

Description. Morphometric data for the holotype and paratypes given in Table 1. Body somewhat compressed, moderately deep on larger specimens. Greatest body depth slightly anterior to dorsal-fin origin. Dorsal profile of head and body convex from upper lip to vertical through anterior nares, straight to slightly concave from latter point to tip of supraoccipital spine, convex from tip of supraoccipital spine to terminus of dorsal-fin base, straight from latter point to adipose fin, and slightly concave between adipose fin and origin of anteriormost dorsal procurrent caudal-fin ray. Ventral profile of head and body convex from lower lip to anal-fin origin (in specimens with exserted pelvic bones, profile somewhat pointed around area of exsertion and nearly straight from portion along pelvic-spine to anal-fin origin), straight to slightly convex along anal-fin base, and slightly concave from terminus of anal-fin base to insertion of anteriormost ventral procurrent caudal-fin ray.

Jaws equal in length, mouth terminal. Posterior terminus of maxilla barely reaching vertical through anterior margin of orbit. Teeth robust ( Fig. 3 ), cusps aligned along distal tooth margin. Premaxillary teeth in two rows; outer teeth row with four (4) or five (17) tricuspid teeth; inner teeth row with five (21) teeth bearing three to five cusps; symphyseal tooth of inner series comparatively narrow, asymmetrical, with lower number of cusps on medial side. Maxilla with one (4), two (13), or three (4) teeth bearing one or three cusps; anteriormost tooth usually the largest. Dentary with 12 (2) or 13 (1) teeth; four or five anteriormost teeth larger with five cusps; symphyseal tooth usually symmetrical; series of eight or nine posterior teeth abruptly smaller, with one or three cusps. Gillrakers on first gill arch seven (1), eight (1) or nine (1) on epibranchial, one (3) on cartilage between ceratobranchial and epibranchial, ten (3) on ceratobranchial, and two (2) or one (1) on hypobranchial. Branchiostegal rays four (3).

Scales cycloid, circuli distributed over whole area of scales, with none or few slightly divergent radii extending to posterior margin of scales. Lateral line slightly curved ventrally, 47 (1), 48 (3), 49 (12), 50* (16), or 51 (6) perforated scales continuous from supracleithrum to base of caudal fin. Longitudinal scale rows between dorsal-fin origin and lateral line 10 (8), 11* (21) or 12 (1). Longitudinal scale rows between lateral line and pelvic-fin origin eight (26)* or nine (3). Median series of scales along middorsal line between tip of supraoccipital process and origin of dorsal fin absent. Circumpeduncular scales 18 (19) or 19 (6)*. Single row of six to nine scales covering base of anteriormost anal-fin rays.

Dorsal-fin rays ii,9* (42); distal margin of dorsal fin straight to slightly rounded. Dorsal-fin origin around middle of standard length; first dorsal-fin pterygiophore inserting posterior to neural spine of 9 th (3) vertebra and insertion of dorsal fin posterior to vertical through pelvic-fin origin. Adipose fin present. Anal-fin rays iv or v, 24 (15), 25 (19), 26* (9), or 27 (1); distal margin of anal fin concave; first anal-fin pterygiophore inserting posterior to haemal spine of 16 th (3) vertebra. Pectoral-fin rays i, 11 (5), 12 (17), 13* (16) or 14 (1); tip of pectoral fin not reaching pelvic-fin origin. Pelvic-fin rays i,7 (41); pelvic bone elongate, modified into spine, with anterior portion diverging (in relation to its counterpart) but usually not protruding through body wall. Principal caudalfin rays 10+9 (13); caudal fin forked, lobes somewhat pointed, of similar size. Eleven (1) or 12 (2) dorsal procurrent caudal-fin rays, and nine (1) or ten (2) ventral procurrent caudal-fin rays. Vertebrae 33 (3). Supraneurals four (2) or five (1).

Color in alcohol. Ground color yellowish to tan, darker dorsally ( Fig. 1 ). 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; some specimens with small chromatophores more concentrated on region close to orbit and on upper half of opercle. Ventral portion of head less pigmented than dorsal portion; snout and maxilla tan.

Larger and darker chromatophores sparsely distributed along scales posterior borders, forming a mild reticulate pattern on most of fish body; overall amount of chromatophores reducing gradually through ventral portion resulting in a less conspicuous reticulate pattern. Scales of dorsal portion of body darkened, with patches of relatively small dark chromatophores on its central portion. Abdominal region yellowish, with a few small chromatophores sparsely distributed. Humeral region with two well-defined verticallyelongated blotches, separated by a clearer area. First blotch more evident, situated on the first five or six scales, counted on series just above the lateral line, and extending to about ten vertical series of scales; central portion of blotch with concentration of subjacent darker pigment, forming a black horizontal narrow bar (with nearly twice the width of dark longitudinal line) that extends anteriorly to reach the first scale series behind opercle and is interrupted posteriorly by the clearer area. Dorsal portion of first blotch darker and separated from ventral portion by an unpigmented horizontal thin line just below the horizontal bar. Second humeral blotch situated on area of seven to nine scales, counted on series just above the lateral line, vertically covering nine to eleven series of scales, and horizontally covering three or four scales on its widest portion.A well defined straight dark line extends from rear of second humeral blotch to caudal peduncle, where it becomes enlarged and forms an elongated blotch that extends to the distal tip of the median caudal-fin rays ( Fig. 2 ); dark line positioned above the lateral line (with width approximately half the height of the scale), formed by subjacent dark pigment, and aligned to the horizontal trace of first humeral blotch. Blotch on caudal peduncle restricted to area posterior to vertical through adipose-fin insertion; in most specimens this blotch covers one or two scales row above and below the lateral line; blotch somewhat ventrally displaced in various specimens.

Dorsal fin somewhat dusky, with rays outlined by small, dark chromatophores.Anal, pectoral, and pelvic fins darkened in a similar pattern as dorsal fin, but with chromatophores more sparsely distributed, not forming lines along rays; anal fin in some specimens with concentration of dark chromatophores on interradial membranes of proximal portion of rays. Caudal fin with rays outlined by small, dark chromatophores; up to seven median rays and interradial membranes darkened by the caudal blotch. Adipose fin with scattered dark chromatophores.

Color in life. Overall body coloration silvery, with guanine covering lateral and ventral surfaces of head, ventral and lateral portions of body, and anteroventral portion of caudal peduncle. Head and body with iridescent hues of blue and green; head also with golden hues. Areas around posterodorsal portion of head, opercle, pectoral-fin insertion, snout and iris orangeyellowish; dorsalmost portion of iris red. Dorsal portions of head and body somewhat dark. Central portion of first humeral blotch distinctly visible and remaining areas of humeral blotches inconspicuous. Dark longitudinal midline and caudal-peduncle blotch poorly visible. Median caudal-fin rays black. All fins orange-reddish, except for the yellow pectoral.

Sexual dimorphism. Secondary sexual characters were not observed on examined specimens.

Geographic distribution and ecological notes. Jupiaba citrina is known from the rio Aripuanã drainage, rio Madeira basin. Specimens were sampled from two distinct habitats, represented by igarapés of Parque Estadual Igarapés do Juruena, on northwest of Mato Grosso State, and igarapés of Reserva Extrativista do Guariba, on southeast Amazonas State, Brazil ( Fig. 4 ). Specimens of J. citrina from Amazonas State were found in small black water igarapé 2.5 m wide and 0.5 m deep, with preserved riparian vegetation, slow water current, bottom with sand and pebbles, pH 5.5 and water temperature of 26°C. Other species sampled syntopically are Aequidens cf. palidus, Aequidens tetramerus, Apistograma aff. linkei, Crenicichla pellegrini , Crenicichla proteus , Characidium sp., Erythrinus erythrinus , Gymnotus anguillaris , Gymnotus sp., Helogenes marmoratus , Hoplias malabaricus , Hyphessobrycon aff. agulha , Megalechis picta , Moenkhausia oligolepis , Nemuroglanis sp., and Rhamdia quelen . Specimens from northwest of Mato Grosso State were sampled in various clear water igarapés of Parque Estadual Igarapés do Juruena, with sandy bottom and deposits of organic matter, up to 3 meters wide and around 0.6 m deep, and well preserved riparian vegetation.At this location, Jupiaba citrina was sampled syntopically with a series of fish species, including two congeners, J. anteroides and J. apenima , and a somewhat similarly colored species of Moenkhausia .

The analysis of the stomach contents of three paratypes revealed presence of ants, larvae of Diptera (chironomid), Trichoptera, nematods, unidentified insect fragments, filamentous algae, unidentified vegetal fragments and sediments. The species apparently has omnivorous and opportunistic feeding habits.

Etymology. From the Latin citrus, meaning lemon, orange, in allusion to the orange-yellowish coloration of body portions of the species in life.

Remarks. Jupiaba citrina apparently belongs to a putative group of Jupiaba , including J. abramoides , J. anteroides , J. apenima , J. asymmetrica , J. poranga , and J. yarina , which share a series of external features, as absence of series of scales on predorsal median area, elevated number of body scales (43-66), and a relatively long pelvic bone (9.6-17.2%). Within this group of species, Jupiaba abramoides , J. anteroides , J. poranga , and J. citrina share the uncommon possession of two well defined vertically-elongated humeral blotches (the first with a central darker horizontal portion anteriorly-elongated) followed by a well defined black line, which may indicate a close relationship between these forms. Distinction on coloration of these species is mainly restricted to the caudal peduncle area (see Diagnosis). Jupiaba apenima , J. asymmetrica , and J. yarina do not have the details of body coloration described for the four species cited above, but, on the other hand, possess an horizontally-elongated blotch on caudal peduncle somewhat similar to that observed in specimens of J. citrina .

The new species occurs simpatrically with a somewhat similarly colored species of Moenkhausia , yet to be described. Resemblance on overall body shape and coloration of Jupiaba with other small characid species was previously discussed by Zanata et al. (in press), who putatively interpreted the remarkable similarities among Jupiaba yarina , J. apenima , and Moenkhausia sp. as a mimicry association. Up to date, cases of possible mimicry with Jupiaba species are known only to the group that J. citrina putatively belongs ( J. abramoides , J. anteroides , J. apenima , J. asymmetrica , J. poranga , J. yarina ). Thus, other cases of characids mimicking species of Jupiaba involves J. abramoides , J. anteroides and Astyanax anterior Eigenmann , observed in sympatry in the rio Tiquié, upper rio Negro, and Astyanax sp. with J. anteroides and J. poranga in tributaries of the rio Teles Pires (Zanata et al., in press).

Jupiaba citrina is possibly endemic to the rio Aripuanã drainage. The apparently high degree of endemism of the area was already discussed elsewhere, with about ten endemic described species suggested by Kullander (1995) and Benine (2002). Recent collecting efforts resulting from various inventory projects carried out on rio Aripuanã drainage continuously reveal new and possibly endemic fish species ( Rocha et al., 2008a, 2008b; present paper), attesting the importance of new investigations of its ichthyofauna and conservation of the area.

Comparative material examined. In addition to data from species of Jupiaba cited under Zanata (1997) publication, the following material was utilized for the comparative study: Jupiaba anteroides : Brazil, Mato Grosso, rio Madeira basin: UFBA 4691, 3, 76.6-91.8 mm SL; UFBA 4690, 1, 58.7 mm SL. Amazonas, rio Madeira basin: INPA 26228, 12, 50.4-73.7 mm SL. Jupiaba apenima MZUSP 91693, 3, 48.5-58.7 mm SL, Brazil, Mato Grosso, rio Xingu basin. Jupiaba asymmetrica INPA 26422, 7, 31.2-39.4 mm SL, Brazil, Amazonas, rio Madeira basin. Jupiaba cf. poranga : Brazil, Mato Grosso, rio Tapajós basin: UFBA 4695, 14, 26.8-49.2 mm SL; UFBA 4696, 12, 32.7-51.1 mm SL. Jupiaba zonata : Brazil, Amazonas, rio Madeira basin: INPA 26426, 6, 30.9-38.7 mm SL; INPA 26288, 2, 30.1-34.0 mm SL. Moenkhausia sp.: Brazil, Mato Grosso, rio Madeira basin: UFBA 4698, 1, 43.4 mm SL; UFBA 4699, 1, 55.8 mm SL.

Figures

Fig. 1. Jupiaba citrina, holotype, INPA 32026, 60.5 mm SL, Brazil, Amazonas,Apuí, rioAripuanã drainage, igarapé on the left margin of the rio Guariba.

Fig. 2. Caudal fin of Jupiaba citrina, paratype, INPA 32027, 48.8 mm SL, Brazil, Amazonas,Apuí, rioAripuanã drainage, igarapé on the left margin of the rio Guariba.

Fig. 3. Premaxilla (a), maxilla (b) and dentary (c) of Jupiaba citrina, paratype, INPA 32028, 57.7 mm SL; lateral view; left side. Scale bar = 1 mm.

Fig. 4. Geographical distribution of Jupiaba citrina. Each symbol may represent more than one sample or locality. Triangle indicates the type-locality.