Hyphessobrycon cyanotaenia Zarske and Ǵery, 2006

Fernando C. P. Dagost, anoela M. F. Mar, cila Cam & ávio C. T. Li, 2016, A New Species of Hyphessobrycon (Characiformes: Characidae) from the Upper Rio Juruena Basin, Central Brazil, with a Redescription of H. cyanotaenia, Copeia 104 (1), pp. 250-259 : 254-257

Hyphessobrycon cyanotaenia Zarske and Ǵery, 2006

Figure 5A–C; Table 2

Hyphessobrycon cyanotaenia Zarske and Ǵery, 2006:43 –46, figs. 4–6 (description; type locality, ‘‘vermutlich Brasilien, Para, Rio Guamá ’’).

Diagnosis.— Hyphessobrycon cyanotaenia can be distinguished from most congeners, except H. cachimbensis , H. fernandezi , H. melanostichos , H. nigricinctus , H. paucilepis , H. psittacus , H. scholzei , H. sovichthys , H. stegemanni , H. taphorni , H. tuyensis , and H. vilmae by the presence of a well-defined, relatively narrow dark midlateral stripe on body extending from the posterior margin of the eye to the middle caudal-fin rays (vs. a well-defined longitudinal stripe absent, stripe starting approximately at vertical through the dorsal-fin origin, or midlateral dark stripe that becomes blurred towards the caudal peduncle).

It differs from all the aforementioned species, except H. cachimbensis , H. melanostichos , and H. nigricinctus , by the presence of a humeral blotch (vs. absence). It is distinguished from H. cachimbensis , H. melanostichos , and H. nigricinctus by having a concentration of dark chromatophores along unbranched rays and distal portions of anteriormost branched rays of dorsal and anal fins ( Fig. 5 ; vs. dorsal and anal fins hyaline), distal margin of anal fin slightly convex to straight, with last unbranched ray and first to second branched ray shorter than the subsequent branched rays (vs. anal-fin falcate, with last unbranched ray and first and second branched rays longer than remaining rays), and presence of a longitudinal midlateral stripe bright bluish in life ( Fig. 5 C; vs. absence).

Description.— Morphometric data presented in Table 2 . Body compressed and moderately high; greatest body depth slightly anterior to dorsal-fin origin. Dorsal profile of head slightly convex from upper lip to vertical through posterior nostril, slightly convex from that point to the vertical through middle of eye, concave to straight from latter point to tip of supraoccipital spine. Dorsal profile of body convex along predorsal region, straight along dorsal-fin base, straight from terminus of dorsal fin to adipose-fin origin, and straight to slightly concave from that point to origin of anteriormost dorsal procurrent caudal-fin ray. Ventral profile of head and body convex from tip of lower lip to pelvic-fin origin, straight to slightly concave between that point to origin of anal fin, slightly convex to straight along anal-fin base, and straight to slightly concave from latter point to origin of anteriormost ventral procurrent caudal-fin ray.

Jaws equal, mouth terminal. Premaxillary teeth in two distinct rows. Outer row with 2(5), 3*(18), or 4(2) tricuspid teeth. Inner row with 5*(23) or 6(2) penta- to heptacuspid teeth. Posterior tip of maxilla at vertical through posterior half of second infraorbital. Maxilla with 1(1), 2*(23), or 3(1) conical to pentacuspid teeth. Dentary with 4*(11) or 5(14) larger penta- to heptacuspid teeth followed by a series of 6(1) or 7(1) diminute conical teeth. Central median cusp in all teeth longer than lateral cusps. Branchiostegal rays 4(2). First gill arch with 2(2) gill rakers on hypobranchial, 9(2) rakers on ceratobranchial, 1(2) rakers on intermediate cartilage, and 6(2) rakers on epibranchial.

Scales cycloid, with 3–5 radii on posterior border, and conspicuous circulii anteriorly. Lateral line incomplete, with 5(1), 6(6), 7*(8), 8(7), or 9(2) perforated scales and 29(2), 30*(13), 31(9), or 32(1) total scales on longitudinal series. Longitudinal scale rows between dorsal-fin origin and lateral line 4(1) or 5*(24). Longitudinal scale rows between lateral line and pelvic-fin origin 3(3) or 4*(22). Scales along middorsal line between posterior tip of supraoccipital process and dorsal-fin origin 9*(14) or 10(11). Horizontal scale rows around caudal peduncle 12*(25). Base of anteriormost analfin rays covered by series of 3 or 4 scales. Caudal fin not scaled.

Supraneurals 5(2). Dorsal-fin rays ii,8(2), iii,8(4), or ii,9*(19). First dorsal-fin pterygiophore inserted posterior to neural spine of 10th(2) vertebra. Base of last dorsal-fin ray at vertical through base of first branched anal-fin ray. Pectoralfin rays i*(25), 9(3), 10*(14), or 11(8). Pelvic-fin rays i*(25), 6(21) or 7*(4). Adipose fin present. Anal fin with iii(2), 13(2), 14*(8), 15(11), or 16(3) rays. First anal-fin pterygiophore inserted posterior to haemal spine of 17th(2) vertebra. Principal caudal-fin rays i,9,8,i*(23) or i,8,7,i(2); caudal fin forked, lobes of similar size. Dorsal procurrent caudal-fin rays 10(2); ventral procurrent caudal-fin rays 9(1) or 10(1). Total vertebrae 32(2): precaudal vertebrae 16(2) and caudal vertebrae 16(2).

Color in alcohol.— Overall ground coloration of head and body beige ( Fig. 5 A, B). Dorsal portion of head and body dark. Snout and jaws with concentration of dark chromatophores, infraorbital series with scattered dark pigmentation, except for the 5th and 6th infraorbitals, densely pigmented with dark chromatophores, continuing with dark longitudinal stripe. Humeral blotch conspicuous, overlapping with midlateral stripe, with diffuse borders, encompassing approximately two scales horizontally and one vertically. Dark midlateral stripe on body, extending from snout to tip of middle caudalfin rays. Thin longitudinal line formed by subjacent dark pigmentation along horizontal septum starting approximately at vertical through dorsal-fin origin to caudal peduncle. Relatively faint reticulated pattern present on first three to four horizontal scale rows, formed by concentration of chromatophores on posterior border of scales. Abdominal region with only sparse chromatophores; scattered dark chromatophores above anal fin. Dorsal, pelvic, and anal fins with concentration of dark chromatophores along unbranched rays and distal portions of anteriormost branched rays, forming distinct thin dark line. Remaining rays with few scattered dark chromatophores. Chromatophores along distal edge of anteriormost rays of pectoral and pelvic fins and along unbranched rays and over distal portions of first branched rays of dorsal and anal fins. Adipose fin with concentration of brown chromatophores at its base and middle portions, distal portion with dark pigmentation. Outermost upper and lower caudal-fin rays with dark chromatophores along their entire length, remaining rays with scattered dark pigmentation. Caudal-peduncle blotch absent. Pigmentation at middle caudal-fin rays frequently darker than chromatophores of midlateral stripe, especially in juveniles.

Color in life.— Based on pictures of freshly collected specimens ( Fig. 5 C) and photographs of specimens kept in aquarium (e.g., Zarske and Ǵery, 2006:46, fig. 16; Hoffmann and Hoffmann, 2012:37). Middorsal ground coloration olive green, midventral clear, with silvery hue ( Fig. 5 C). Jaws and snout light gray. Infraorbitals 1–4, preopercle and opercle silvery. Dorsal portion of opercle and fifth and sixth infraorbitals densely pigmented with dark chromatophores. Dorsal portion of eye dark. Bright bluish stripe above and below longitudinal dark stripe. Fins mostly hyaline, except for concentration of dark chromatophores (see Color in alcohol section for further details on dark chromatophore patterns on fins).

Sexual dimorphism.— According to Teixeira et al. (2013:617), the slightly convex anal-fin shape of Hyphessobrycon cyanotaenia seems not to be a dimorphic character, since it is present in adult males and females, which was confirmed in the present study. However, from 24 dissected specimens with slightly convex anal-fin shape (25.7–34.3 mm SL), 19 were males (26.4–34.3 mm SL), four females (26.5–31.4 mm SL), and one immature (25.7 mm SL). These data indicate that despite the fact that this feature is not a dimorphic character, there is a tendency for it to be more frequently found in mature males than in females or immature specimens since most mature females examined (10 of 14, 26.4–32.2 mm SL) present the anal-fin distal shape somewhat straight to slightly concave ( Fig. 5 B). Bony hooks were not observed on fins of any analyzed specimen.

Geographic distribution.— Hyphessobrycon cyanotaenia is known from the upper portions of Rio Juruena (Rio Tapajós basin) and Rio Guapoŕe (Rio Madeira basin), Mato Grosso State, Brazil ( Fig. 4 ). See Remarks for comments on the type locality.

Remarks.— Hyphessobrycon cyanotaenia was described based on material from the aquarium trade, said to be probably from the Rio Guamá, Pará State, Brazil ( Zarske and Ǵery, 2006). However, the analysis of extensive material deposited in some Brazilian ichthyological collections has shown that H. cyanotaenia occurs in the upper portions of the Rio Juruena basin ( Fig. 4 ) and in tributaries of the upper Rio Guapoŕe basin (UFRO-I 21369 and UFRO-I 228602). The Rio Guamá is a relatively small river basin draining the eastern portion of Pará State, immediately to the east of the Rio Tocantins. It is moderately well collected for fishes, and there are so far no corroborated records for H. cyanotaenia for this basin or other neighboring drainages of the Rio Tocantins. Considering the current knowledge of the distribution of Amazonian fishes and the unlikely biogeographic relationships between the Rio Guamá and the Rio Juruena and Rio Guapoŕe basins, the occurrence of H. cyanotaenia in the former is herein considered to be doubtful and should not be included within the known range for the species unless further evidence is provided.

Type material examined.— MTD F 28760, 32.3 mm SL, holotype, ‘‘Importnachzucht (F1) von Hoffmann & Hoffmann, Fundort der Importtiere vermutlich Brasilien, Pará, Rio Guamá ’’; Hoffmann and Hoffmann don., 2006; MTD F 28761–28762, 2, 28.9–33.0 mm SL, paratypes, same data as the holotype; MTD F 28763–28764, 2, 23.5–26.5 mm SL, paratypes, ‘‘Importnachzucht (F1) von Hoffmann & Hoffmann, Fundort der Importtiere vermutlich Brasilien, Pará, Rio Guamá ’’, Hoffmann & Hoffmann don., 2004.

Non-type material examined.— All from Brazil, Mato Grosso State, Rio Juruena drainage, Rio Tapajós basin: MZUEL 8672, 2286, 11.7–35.7 mm SL, MZUSP 115552, 50, 13.9–31.9 mm SL, Sapezal, Rio Juruena, 15 km from Sapezal, 13°32'57.7''S, 59°0 1'53.9''W, 30 August 2013, J. L. O. Birindelli, A. Claro- Garćıa, F. Assega, and E. Santana; MZUSP 104297, 5, 27.1– 33.3 mm SL, Sapezal, Rio Juruena, downstream PCH Santa Lucia ´, 13°32'39'' S, 59°1'48'' W; MZUSP 104298, 31, 16.0– 36.6 mm SL, Sapezal, Rio Juruena upstream PCH Ilha Comprida, 13°12'11''S, 58°59' 0 4''W; MZUSP 104299, 14, 16.1–23.7 mm SL, Campos de Julio´, Rio Juruena, downstream the bridge at BR-364, 14°39'40''S, 59°6'27 ''W. MZUSP 104300, 42, 15.8– 34.8 mm SL, Campos de Julio´, Rio Juruena, Tirolesa farm, 14°16'38''S, 59°5'22'' W; MZUSP 104301, 12, 20.9–27.7 mm SL, Campos de Julio´, Rio Juruena, upstream bridge at BR-364, 14°39'43''S, 59°0 6'42 ''W; MZUSP 104386, 1, 30.8 mm SL, Sapezal, Rio Juruena upstream to PCH Santa Lucia ´, left bank, 13°38'23''S, 59°0 0'28''W; MZUSP 104387, 48, 19.7–33.5 mm SL, Campos de Julio´, Rio Juruena, Tirolesa farm, 14°16'37''S, 59°0 5'22''W; MZUSP 104488, 3, 28.6–29.2 mm SL, Sapezal, Rio Juruena downstream to the PCH Telegráfica, 12°41' 0 5''S, 58°56'29''W; MZUSP 104489, 386, 15.7–33.1 mm SL, 2 CS, 27.8–27.9 mm SL, ZUEC 8515, 10, 24.6–34.2 mm SL, Campos de Julio´, Rio Juruena, Tirolesa farm, 14°16'38'' S, 59°5'22'' W; MZUSP 104490, 278, 16.5–35.7 mm SL, Campos de Julio´, Rio Juruena, Tirolesa farm, 14°16'38''S, 59°0 5'22'' W; MZUSP 104623, 7, 20.7–24.0 mm SL, Sapezal, Rio Juruena, between PCH Cachoeirão and PCH Rondon, 12°58'46 ''S, 58°54'48'' W; MZUSP 104902, 50, 13.7–22.9 mm SL, Campos de Julio´, Rio Juruena, flooded area between Rio Juruena and Cabeceira creek, upstream bridge at road BR-364, 14°39'43 ''S, 59°6'27'' W; MZUSP 104922, 3, 25.9–27.2 mm SL, Sapezal, Rio Juruena, downstream PCH Ilha Comprida, 13°11'32''S, 58°58'51''W; MZUSP 104923, 16, 19.4–31.4 mm SL, Campos de Júlio, Rio Juruena, upstream bridge at road BR-364, 14°39'43''S, 59°6'27'' W; MZUSP 104924, 27, 16.0– 36.6 mm SL, Campos de Julio´, Rio Juruena, upstream bridge at BR-364, 14°39'40''S, 59°0 6'27 ''W; MZUSP 104925, 1, 25.2 mm SL, Campos de Júlio, Rio Juruena, 14°15'47'' S, 59°5'25''W; MZUSP 105448, 18, 18.4–32.5 mm SL, Sapezal, Rio Juruena, upstream PCH Santa Lucia ´, 13°39'18''S, 59°1'12''W; MZUSP 105449, 13, 14.6–36.8 mm SL, Campos de Julio´, Rio Juruena, upstream bridge at road BR-364, 14°39'S 59°6''W; MZUSP 105450, 5, 14.6–36.8 mm SL, Sapezal, Rio Juruena, downstream PCH Telegráfica, 12°37'49''S, 58°56'9''W; MZUSP 105661, 25, 13.9–30.4 mm SL, Campos de Júlio, creek tributary of the Rio Juruena, upstream bridge at road BR- 364, 14°39'40 ''S, 59°0 6'27''W; MZUSP 105662, 7, 22.8–32.3 mm SL, Sapezal, Rio Juruena, downstream PCH Santa Lucia ´, 13°32'37''S, 59°0 1'48''W; MZUSP 105663, 85, 13.4–29.9 mm SL, Sapezal, Rio Juruena, upstream PCH Santa Lucia ´, right bank, 13°37'56''S, 59°0 0'36''W; MZUSP 105664, 394, 15.3– 33.3 mm SL, Campos de Julio´, Rio Juruena, Tirolesa farm, 14°15'19''S, 59°3'11'' W; MZUSP 105671, 11, 16.6–19.5 mm SL, Sapezal, Rio Juruena upstream PCH Santa Lucia ´, left bank, 13°35'45''S, 59°1'58''W; MZUSP 105672, 4, 22.7–30.9 mm SL, Sapezal, Rio Juruena, upstream PCH Santa Lucia ´, left bank, 13°37'55''S, 59°0 3' 0 3''W; MZUSP 105673, 36, 13.5–30.5 mm SL, Sapezal, irrigation channel at road BR-364, near Rio Juruena, 13°32'18'' S, 59°0 0'28''W; UFRO-I 21369, 7, not measured, UFRO-I 228602, 138, not measured, Uirapuru waterfall, tributary of the Rio Guapoŕe basin, 14°24'58''S, 59°27'16'' W.

DISCUSSION

As discussed by Lima et al. (2014:175), the color pattern in Hyphessobrycon heterorhabdus and its putative most closely related congeners, H. amapaensis and H. eschwartzae , is distinctive since those species share a well-defined, elongated humeral blotch which is continuous with a well-defined, dark midlateral stripe that becomes blurred towards the caudal peduncle. In turn, Hyphessobrycon psittacus shares with H. vilmae , as well as with some other congeners, namely, H. fernandezi , H. paucilepis , H. scholzei , H. sovichthys , H. stegemanni , H. taphorni , and H. tuyensis , the combination of the presence of a relatively narrow yet well-marked continuous midlateral stripe from immediately behind the head to the end of caudal peduncle (and into middle caudal-fin rays) and the absence of a humeral blotch. This is in contrast with species presenting a continuous, well-marked, and relatively narrow midlateral stripe which yet possess a discernible humeral blotch overlapping with the midlateral stripe, viz., Hyphessobrycon cachimbensis , H. cyanotaenia , H. melanostichos , and H. nigricinctus .

Beyond the species of Hyphessobrycon with a well-marked and relatively narrow midlateral stripe, other species of the genus have a midlateral, clearly broader dark stripe, distinct from the pattern discussed above. Ǵery (1961) grouped Hyphessobrycon herbertaxelrodi , H. loretoensis , H. metae , and H. peruvianus in the ‘‘ Hyphessobrycon metae -group’’ based on the possession of a dark stripe beginning at the vertical through the middle of the dorsal fin, extending along the posterior lower half of the body. Later, Ǵery (1977) included H. agulha in the group and redefined it based on the presence of the lower half of body dark, especially above the anal fin, and usually the presence of a horizontally elongate humeral spot, more or less united with the asymmetrical broad stripe, referred as the ‘‘ Hyphessobrycon agulha -group.’’ Afterwards, Costa and Ǵery (1994) described H. mutabilis , with similar color pattern and assigned it to the Hyphessobrycon agulha - group. Hyphessobrycon psittacus has a narrower midlateral stripe, similar to the depth of the pupil, in contrast to the broader midlateral stripe with posterior lower half of the body intensely pigmented present in species of the ‘‘ Hyphessobrycon agulha -group’’ sensu Costa and Ǵery (1994).

Similar overall color pattern present in Hyphessobrycon psittacus is found in the recently described species of Hemigrammus , H. ataktos . Considering that the generic limit of Hemigrammus and Hyphessobrycon is solely based on the caudal-fin squamation, a putatively homoplastic morphological condition in Characidae , a comparison with this species is relevant. Besides the absence of the caudal-fin squamation, Hyphessobrycon psittacus can be distinguished from Hemigrammus ataktos by having 16–19 branched analfin rays (vs. 20 or more) and six branched pelvic-fin rays (vs. seven). We take this opportunity to mention that in Marinho et al. (2014), Hemigrammus ataktos was accidentally first introduced as ‘‘ Hyphessobrycon ataktos ’’ on page 258, due to a typing error, an incorrect generic assignment that has no nomenclatural implication since in the remaining article the species is treated as belonging to Hemigrammus .

The distribution of Hyphessobrycon psittacus , along with Crenicichla chicha (cf. Varella et al., 2012) and Moenkhausia nigromarginata , is restricted to the Rio Papagaio basin. The distribution pattern of these species indicates that the Rio Juruena basin, as earlier remarked by Britski and Lima (2008:568), is not as a whole a biogeographic unit, but rather partitioned into different biogeographic regions each harboring endemic taxa. New collection efforts in the region will provide a better understanding of the distribution patterns present in other regions forming the Rio Juruena basin and thus may eventually validate these assumptions.

Figures

Fig. 4. Distribution map of Hyphessobrycon psittacus (white dots) and Hyphessobrycon cyanotaenia (black squares). Star symbol represents the type locality of H. psittacus. Each symbol may represent more than one collection event.

Fig. 5. Hyphessobrycon cyanotaenia, Brazil, Mato Grosso State: (A) MZUSP 104300, 34.5 mm SL, male, Campos de´Julio, Rio Juruena; (B) MZUSP 105448, 28.8 mm SL, female, Sapezal, Rio Juruena; (C) UFRO-I 228602, live specimen, not measured, Nova Lacerda, Rio Guapoŕe basin.

Tables

Table 2. Morphometric data of Hyphessobrycon cyanotaenia, n ¼ 20. SD ¼ standard deviation.

	Range	Mean	SD
Standard length (mm)	23.6–33.4	28.6	—
Percentages of SL
Depth at dorsal-fin origin	30.3–34.0	30.7	1.0
Snout to dorsal-fin origin	51.8–54.3	52.7	0.5
Snout to pectoral-fin origin	24.6–26.2	24.9	0.3
Snout to pelvic-fin origin	45.9–46.9	46.7	0.3
Snout to anal-fin origin	61.9–63.4	62.0	0.4
Caudal-peduncle depth	10.0–10.8	10.6	0.2
Caudal-peduncle length	11.7–13.1	12.3	0.3
Pectoral-fin length	20.5–25.5	23.4	1.0
Pelvic-fin length	15.2–17.9	17.2	0.6
Pelvic-fin origin to anal-fin origin	16.6–18.2	16.8	0.5
Dorsal-fin length	26.2–30.6	29.0	0.9
Dorsal-fin base length	12.8–14.1	13.9	0.4
Anal-fin length	18.2–21.4	20.8	0.9
Anal-fin base length	28.5–31.0	29.7	0.5
Eye to dorsal-fin origin	37.9–40.3	38.1	0.6
Dorsal-fin origin to caudal-fin base	49.5–52.0	51.6	0.5
Head depth	23.8–25.7	25.0	0.3
Head length	24.1–24.9	24.8	0.3
Percentages of HL
Horizontal eye diameter	41.8–46.6	45.6	1.3
Snout length	26.7–28.8	28.1	0.4
Interorbital width	33.8–36.4	35.2	0.5
Upper jaw length	43.3–46.6	43.7	0.9