Bryconops munduruku, Silva-Oliveira, Cárlison, Canto, André Luiz C. & Ribeiro, Frank Raynner V., 2015

Silva-Oliveira, Cárlison, Canto, André Luiz C. & Ribeiro, Frank Raynner V., 2015, Bryconops munduruku (Characiformes: Characidae), a new species of fish from the lower Tapajós River basin, Brazil, Zootaxa 3994 (1), pp. 133-141 : 134-138

Bryconops munduruku , new species

( Figures 1–3 ; Table 1 )

Holotype. INPA 46510, male, 76.6 mm SL, Brazil, Pará State, Aveiro, igarapé Açu, tributary of the right margin of the Tapajós River, about 10 km of the city of Aveiro, 0336’0.99’’S 5514’59.14’’W, 23 May 2013, C. Silva-Oliveira & S. R. Oliveira.

Paratypes. All collected with holotype, Brazil, Pará State, Tapajós River basin: MCP 48315 (5, 34.0– 79.6 mm SL); INPA 46511 (11, 33.5–91.7 mm SL; 2 c&s, 31.8–74.1 mm SL); UFOPA-I-00655 (7, 33.4–96.4 mm SL; 5 c&s, 47.6–63.3 mm SL).

Diagnosis. Bryconops munduruku differs from its congeners, except B. inpai and B. piracolina , by possessing a black adipose fin (vs. adipose fin hyaline in alcohol). It differs from B. inpai and B. piracolina by possessing a hyaline band on the black adipose-fin base (vs. entirely black adipose fin in B. piracolina and B. inpai ). Bryconops munduruku differs further from B. piracolina by having a hyaline dorsal fin (vs. presence of a large black blotch on the dorsal-fin base). Bryconops munduruku differs from other species of the subgenus Creatochanes , except B. inpai , by possessing two humeral blotches (vs. lack of humeral blotch or humeral region with a single humeral blotch in B. humeralis and B. vibex ). It differs further from B. inpai due to the uniform color pattern on the posterior portion of the side of the body (vs. presence of a dark stripe extending posteriorly from the half of the anal-fin base onto the base of the middle caudal-fin rays).

Description. Morphometric data presented in Table 1 . Body shape compressed, greatest body depth located just anterior to dorsal-fin origin. Dorsal profile of body slightly convex from snout tip to dorsal-fin origin; straight to slightly concave from dorsal insertion to adipose-fin origin, gently sloping to beginning of caudal peduncle.

Caudal peduncle concave along dorsal and ventral margins. Ventral profile of head and body convex from lower lip to pelvic-fin origin, and straight from this point to anal-fin origin. Ventral profile straight and posterodorsally inclined along anal-fin base.

Mouth terminal. Posterior extension of maxilla reaching junction between second and third infraorbital bones ( Fig. 2 ); third infraorbital moderately developed, reaching preopercle ventrally. Supraorbital bone present. Premaxillary teeth in two rows, with midcentral cusp more developed than remaining cusps; outer teeth row with 5* (9) or 6 (3) tricuspid teeth; inner tooth row with 5* (10) pentacuspid teeth. Maxillary with 1 (2), 2* (15), or 3 (1) tri- or tetracuspid teeth on contralateral parts ( Fig. 3 ). Dentary with 5 (2) or 6* (6) penta- or hexacuspid teeth, followed by 6 smaller conical teeth.

Dorsal-fin rays ii,8 (3) or ii,9* (28); first unbranched ray about one-half length of second unbranched ray. Dorsal-fin origin slightly ahead of mid-body, positioned vertically through anterior third of pelvic-fin base. Posterior margin of dorsal fin straight to slightly concave. Adipose-fin origin approximately at vertical through base of 18th to 19th anal fin branched rays. Principal caudal-fin rays i,8,8,i (7) or i,8,9,i* (23). Lobes of caudal fin unequal, lower lobe slightly longer than upper lobe. Dorsal procurrent caudal-fin rays 14 (5), ventral procurrent caudal-fin rays 13 (4) or 14 (1). Pectoral-fin rays i,10 (15) or i,11* (15). Tip of pectoral fin reaching slightly beyond half of distance between pectoral and pelvic fins. Pelvic-fin rays i,7*(30). Pelvic fin originating at vertical through middle of dorsal-fin base, reaching slightly beyond half the distance between pelvic and anal fins. Anal-fin rays iii, 23* (16), iii, 24 (6), iii, 25 (6), or iii, 26 (2). Anal-fin origin located posterior to vertical through base of last dorsal-fin ray. Last unbranched anal-fin ray and first to fourth branched rays slightly longer than remaining anal-fin rays. Distal margin of anal fin concave.

Lateral line reaching base of caudal-fin rays. Longitudinal scales in lateral line 44 (6), 45* (18), or 46 (8). All scales of lateral line pored. Scale rows between lateral line and dorsal-fin origin 7* (22) or 8 (8); scale rows between lateral line and pelvic-fin origin 3* (18) or 4 (12). Predorsal scales 10 (9) or 11* (5), arranged in a regular series. Scale rows around caudal peduncle 15 (5) or 16* (3). Precaudal vertebrae 19 (5); caudal vertebrae 22 (1) or 23 (4); total vertebrae 41 (1) or 42 (4). Supraneurals 7 (4). First dorsal fin pterygiophore located between 11th and 12th vertebrae. Gill rakers of first gill arch 16 (5): 2 (5) hypobranchial, 7 (5) ceratobranchial, 1 (5) on cartilage between ceratobranchial and epibranchial, 6 (5) epibranchial. Gill rakers setiform. Branchiostegal rays 5: 4 (5) on ceratohyal and 1 (2) on epihyal.

Color in alcohol. Overall ground coloration of body dusky brown to yellowish. Dorsal profile of head and snout dark. Infraorbitals, maxillary, and ventral region of opercle silver. Infraorbital 5 and dorsal portion of opercle with scattered chromatophores. Lips and anterior portion of maxilla with dense concentration of chromatophores. Gular region light. Dorsolateral region of body darkened. Scales of lateral region of body with chromatophores concentrated on posterior borders. Two humeral spots present; first humeral spot conspicuous, vertically elongated, extending over three rows of scales above lateral line and horizontally over two rows of scales; second humeral spot inconspicuous, vertically elongated; its form resembling the number 3. Dorsal-fin rays darkened from base to mid-section, light at distal portion. Black adipose fin, but hyaline along its base. Caudal fin with concentrated chromatophores on half nearest most external rays of ventral and dorsal lobes. Pectoral, pelvic, and anal fins hyaline, with few scattered chromatophores.

Color in life. General body color reddish on dorsolateral region above lateral line; light grey from lateral line to ventral scale series. Upper portion of head, opercle, intraorbital bones, and maxilla dark grey. Upper margin of orbit red; anterior and posterior margins yellowish. Dorsal fin red from base to mid-length of rays; distally hyaline. Black adipose fin, with narrow hyaline band at base. Caudal fin red at base to mid-length of dorsal and ventral rays; distal region of lobes hyaline. Pectoral and pelvic fins, as well as first anal-fin rays, yellow.

Sexual dimorphism. Mature males bear hooks on the anal, pelvic, and dorsal-fins rays. Dorsal and pelvic-fin hooks are smaller, fewer in number and spine-like. Anal-fin hooks larger and more numerous, present from distal half of the third unbranched ray, decreasing in number and size to15th branched ray. Hooks absent in females.

Distribution. Bryconops munduruku is known from the igarapé Açu, a tributary on the right margin of the Tapajós River, about 10 km from Aveiro, Pará State, Brazil ( Fig. 4 ).

Etymology. The specific epithet is given in allusion to a tribe of Munduruku Indians denominated Tapajós- Tapera, who settled on the right margin of the Tapajós River, giving rise to what today is the city of Aveiro, the type locality of Bryconops munduruku . A noun in apposition.

Ecological notes. igarapé Açu presents clear water running over sandy beds. Its headwaters are located within the limits of the Tapajós National Forest and are densely covered by marginal vegetation. Representatives of Bryconops munduruku were collected in rapid flowing waters among stretches, where it occurs syntopically with Bryconops cf. giacopinii , Hyphessobrycon cf. agulha , Hemigrammus sp., and Moenkhausia comma .

Figures

FIGURE 1. Bryconops munduruku, INPA 46510, holotype, male, 76.6 mm SL, Brazil, Pará State, Aveiro, Igarapé Açu, tributary of the lower Tapajós River basin.

FIGURE 2. Bryconops munduruku, UFOPA-I- 00655, paratype, 71.5 mm SL (c & s). Left side of the premaxilla, maxilla, and dentary. Lateral view. Scale bar = 1 mm.

FIGURE 3. Bryconops munduruku, UFOPA-I- 00655, paratype, 63.3 mm SL (c & s). Maxilla (MA), infraorbitals (IO) 1 - 5 and antobital (AO). Scale bar = 1 mm.

FIGURE 4. Map of part of Central and Northern South America, showing the type locality of Bryconops munduruku (black square) in the lower Tapajós River basin.

Tables

TABLE 1. Morphometric data of holotype and 30 paratypes of Bryconops munduruku. Holotype is included in the ranges and means. SD = standard deviation.

	Holotype Range	Mean	SD
Standard Length (mm)	76.6 31.8–96.4	61.4	-
Percents of Standard Length
Predorsal length	41.4 41.4–50.6	48.8	1.6
Preanal length	66.7 60.4–67.3	65.3	1.4
Prepelvic length	49.0 47.4–52.6	49.8	1.3
Prepectoral length	26.4 25.5–29.1	27.1	0.8
Dorsal-fin base length	13.1 9.8–17.9	14.5	1.4
Dorsal origin to pectoral origin	37.3 31.5–38.5	35.8	1.7
Dorsal origin to pelvic origin	33.7 27.1–35.3	31.9	2.0
Dorsal terminus to anal origin	35.1 27.6–37.8	34.1	2.5
Dorsal terminus to anal origin	28.1 21.5–30.8	27.4	2.2
Dorsal terminus to pelvic origin	33.4 27.7–35.4	32.1	1.9
Dorsal terminus to anal terminus	31.9 26.3–35.3	31.0	1.7
Dorsal terminus to adipose origin	22.1 21.3–26.6	22.9	1.1
Adipose terminus to hypural plate	14.6 11.7–16.0	14.4	1.1
Pectoral origin to pelvic origin	23.8 20.6–25.6	23.2	1.1
Anal-fin base length	25.7 24.6–29.5	27.2	1.2
Anal origin to adipose origin	30.4 27.1–33.0	30.1	1.6
Length of caudal peduncle	12.4 9.6–14.3	12.5	1.0
Adipose origin to base of last anal-fin ray	10.8 10.8–13.5	12.4	0.7
Maxillary length	14.0 13.1–15.7	14.1	0.7
Snout length	8.0 5.9–8.2	6.9	0.6
Horizontal orbit diameter	8.4 7.1–12.0	9.7	1.0
Head length	26.0 22.2–29.2	26.1	1.4
Percents of Head Length
Tip of snout to tip supraoccipital spine	86.4 81.7–102.7	89.1	4.6
Maxilla to pectoral origin	45.7 44.6–59.8	50.8	3.9
Maxilla to posterior margin of opercle	55.8 51.7–69.3	57.8	3.7
Anterior margin of orbit to maxilla	38.2 32.6–46.7	39.2	2.7
Posterior margin of orbit to opercle	41.0 31.3–48.7	36.7	3.9
Maxillary length	53.8 48.5–60.7	54.0	2.1
Snout length	30.7 21.5–32.0	26.3	2.2
Horizontal orbit diameter	32.2 32.2–44.7	7.5	2.8