Hemibrycon helleri Eigenmann, 1927

Bertaco, Vinicius A. & Malabarba, Luiz R., 2010, A review of the Cis-Andean species of Hemibrycon Günther (Teleostei: Characiformes: Characidae: Stevardiinae), with description of two new species, Neotropical Ichthyology 8 (4), pp. 737-737: 737-

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http://doi.org/ 10.1590/S1679-62252010000400005

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scientific name

Hemibrycon helleri Eigenmann, 1927
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Hemibrycon helleri Eigenmann, 1927  

Figs. 5-6 View Fig View Fig

Hemibrycon helleri Eigenmann, 1927: 402   (in key), 406 (pl. 96, fig. 2; original description; type material; type locality: río Comberciato, río Urubamba drainage).

Diagnosis. Hemibrycon helleri   is distinguished from all congeners, except H. jelskii   , by the size of humeral spot (over 7-8 vs. 3-6 horizontal series of scales). It differs from H. jelskii   by the number of branched anal-fin rays (19-23 vs. 25-30, Fig. 2 View Fig ),

742 A review of the Cis-Andean species of Hemibrycon   and by the number of scales along anal-fin base scale sheath (6-12 vs. 13-28). Hemibrycon helleri   is rather similar to H. inambari   new species, but can be distinguished by the size of humeral spot (over 7-8 vs. 5-6 horizontal series of scales), number of predorsal scales (16-18 vs. 13-16), and by the total number of vertebrae (41-43 vs. 39-40).

Description. Morphometric data for H. helleri   summarized in Table 1. Largest male 78.6 mm SL, largest female 81.6 mm SL. Body compressed and moderately elongate; greatest body depth at vertical through middle length of pectoral fins. Dorsal profile of head straight to slightly convex. Dorsal body profile convex from occipital bone to base of last dorsal-fin ray; straight from this point to adipose-fin origin. Ventral profile of head nearly straight to slightly convex. Ventral body profile convex from pectoral-fin origin to pelvic-fin origin, and straight to slightly convex to anal-fin origin. Body profile along analfin base posterodorsally slanted. Caudal peduncle elongate, nearly straight to slightly concave along dorsal and ventral margins.

Snout rounded from margin of upper lip to vertical through anterior nostrils. Head small. Mouth terminal, mouth slit nearly at horizontal through middle of eye. Maxilla long and slightly curved, aligned at angle of approximately 45º to longitudinal body axis, and its posterior tip extending below orbit, reaching nearly to vertical through center of eye.

Premaxilla with two tooth rows; outer row with 3-5, tricuspid teeth with central cusp slightly longer; inner row with 4 tetra- to pentacuspids teeth, gradually decreasing in length from first to third teeth and last tooth smallest; central cusp twice or three times longer and broader than other cusps. Maxilla fully toothed with 8-14 uni- to tricuspid teeth, with central cusp longer. Three anteriormost dentary teeth larger, with 5 cusps, followed by medium sized tooth with 3 cusps, and 7-9 teeth with 1-3 cusps or conical; central cusp in all teeth two to three times longer and broader than other cusps. Cusp tips slightly curved posteriorly and lingually ( Fig. 6 View Fig ).

Dorsal-fin rays ii,8 (n = 33); first unbranched ray approximately one-half length of second ray. Dorsal-fin origin located posterior to middle of SL and posterior to vertical through pelvic-fin origin. Profile of distal margin of dorsal fin nearly straight to slightly concave. Males with bony hooks in distal one-third of first branched rays. Adipose-fin located at vertical through insertion of last or posterior to last anal-fin ray. Analfin rays ii-v,19-23 (mode = 21, n = 37, Fig. 2 View Fig ). Anal-fin profile slightly convex in males and nearly straight in females. Analfin origin approximately at vertical through insertion in the last dorsal fin rays. Anal-fin rays of males bearing one pair of small bony hooks along posterolateral border of each segment of lepidotrichia, along last unbranched ray and twelfth to sixteenth branched rays. One male paratype had bony hooks in all analfin branched rays. Hooks usually located along posteriormost branch and distal 1 /

2

to 2 /

3

of each ray. Pectoral-fin rays i,10-11

V. A. Bertaco & L. R. Malabarba 743

(mode = 10, n = 27). Pectoral-fin tip reaching pelvic-fin origin in males. Males with bony hooks on distal portion of unbranched and all branched rays. Pelvic-fin rays i,6,i (n = 30). Pelvic-fin origin located 4-5 predorsal scales anterior to vertical through dorsal-fin origin. Pelvic fin of males usually bearing one small bony hook per segment of lepidotrichia along ventromedial border of fourth to eighth branched rays. Caudal fin forked with 19 principal rays without bony hooks (n = 30); lobes similar in size. Caudal-fin base with a few scales in half-length, followed by one large scale in each lobe. Dorsal procurrent rays 8-10 and ventral procurrent rays 9-10 (n = 12).

Scales cycloid, moderately large. Lateral line complete with 42-45 (mode = 42, n = 23, Fig. 3). Scale rows between dorsalfin origin and lateral line 7-8 (mode = 8, n = 35); scale rows between lateral line and pelvic-fin origin 5-6 (mode = 6, n = 35). Predorsal scales 15-18, arranged in regular series (mode =16,n = 34). Scales rows around caudal peduncle 16-18 (mode = 16, n = 27). Axillary scale on pelvic-fin origin extends posteriorly covering 2-3 scales. Scale sheath along anal-fin base with 6-12 scales in single series, extending to base of most anterior branched rays.

Precaudal vertebrae 19-21; caudal vertebrae 22-23; total vertebrae 41-43 (n = 12). Supraneurals 6-7 (n = 12). Gill rakers on upper limb of outer gill arch 6-7, and on lower limb 10-11 (n = 11).

Color in alcohol. Type material discolored. Color based on the non-type specimens. General ground body color yellowish. Dorsal portion of head and body with dense concentration of black chromatophores. Dorsolateral portion of head and body with scattered black chromatophores. Midlateral body silvery. One large and vertical black humeral spot, located over fourth to sixth lateral line scales and extending over 7-8 horizontal series of scales, including lateral line. Midlateral dark stripe extending from humeral region to middle caudal-fin rays, broad in the caudal peduncle. Abdominal region almost devoid of black chromatophores. Adipose fin densely black pigmented. Dorsal and caudal fin with black pigmentation diffuse and anal fin with small black chromatophores along its border forming narrow stripe. Pectoral and pelvic fins hyaline ( Fig. 5 View Fig ).

Sexual dimorphism. Males of Hemibrycon helleri   are easily recognized by the presence of bony hooks on the dorsal-, pectoral-, anal- and pelvic-fin rays. Males and females also slightly differ in body depth ( Table 1), and in anal-fin shape, which is slightly convex in males and nearly straight in females. Mature males with gill gland on first gill arch, covering the first branchial filaments ( Fig. 7 View Fig ).

Distribution. Hemibrycon helleri   is known from río Comberciato, and río Urubamba, upper río Ucayali drainage, Cusco, Peru ( Fig. 4 View Fig ).

Remarks. Eigenmann (1927: 406) described Hemibrycon helleri   and designated the holotype as “13565 Type” [ MCZ 31565 View Materials , the catalog number mistakely cited in the original description] and 17 paratypes (CM 7439, IU 13754) from río Comberciato, Peru. Later, Eigenmann & Allen (1942: 216) listed the type material but did not provided the catalog number for types of H. helleri   , but listed 18 type specimens along with their lengths, and type locality. Böhlke (1953) in his catalog of types from Stanford University did not list types of H. helleri   . Ibarra & Stewart (1987: 43) listed three paratypes of H. helleri   but did not provide the catalog number of FMNH specimens.Eschmeyer (1998: 717) listed two possible lots as holotype, “? MCZ 31565 View Materials ” (1) or MCZ 30980 View Materials (1), and the following lots as paratypes: CAS 44354 View Materials [ex IU 13754] (5) and FMNH 58439 (3), followed posteriorly by Lima et al. (2003: 129); there are 8 paratypes missing.

According to Eigenmann (1927) the holotype has 100 mm of size [total length - TL]. The specimen from MCZ 31565 View Materials measures 78.9 mm SL and 94.9 mm TL and the specimen from MCZ 30980 View Materials has 81.1 mm SL and 98.9 mm TL. Although the specimen from MCZ 30980 View Materials is larger and more close to the body size of the holotype mentioned by Eigenmann (100 mm TL), the specimen corresponding to the original catalog number referred as the holotype MCZ 31565 View Materials (mistyped 13565) has the same number of branched anal-fin rays of the specimen illustrated as the holotype in the figure 2 by Eigenmann (1927, plate 96), 23 vs. 22 branched anal-fin rays on specimen of lot MCZ 30980 View Materials , and so we consider that the specimen available as MCZ 31565 View Materials is actually the holotype. Based on data and fish images taken from the lots MCZ 30980 View Materials (1), and MCZ 30981 View Materials (7) we can confirm that these specimens are part of the missing type series of H. helleri   . The specimen listed as nontype by Eigenmann (1927: 406; CAS 44355 View Materials , ex IU 17611) from río Crisnejas, Peru is actually a specimen of H. huambonicus   .

Material examined. Holotype. MCZ 31565 View Materials , female (x-ray), 78.9 mm SL, río Comberciato, a small tributary of middle río Urubamba, 30 miles above the Pongo de Mainique , Cusco, Peru , 1,800 ft. elev., ca. 12º28’S 73º07’W, 1910-1915, E. Heller (Yale-National Geographic Expedition) GoogleMaps   . Paratypes. CAS 44354 View Materials , 5 View Materials , 39.6 View Materials -72.0 mm SL   , FMNH 58439 View Materials , 3 View Materials (x-ray), 36.4-78.5 mm SL   , MCZ 30980 View Materials , 1 View Materials (x-ray), 81.1 mm SL   , MCZ 30981 View Materials , 8 View Materials (x-ray), 46.1-79.2 mm SL, collected with the holotype   . Non-type specimens. Peru, Cusco, río Urubamba drainage   : ANSP 180775 View Materials , 4 View Materials (1 c&s), 53.3-81.1 mm SL, quebrada Rosaríomayo, west of Quelluono on road to Kiteni , 12º46’28”S 72º39’06”W, 19 Jul 2004 GoogleMaps   . ANSP 180777 View Materials , 2 View Materials , 20.4-72.4 mm SL, río Amaybamba, southeast of Quillabamba on road to Ollantaytambo , 12º59’55”S 72º31’24”W, 17 Jul 2004 GoogleMaps   . ANSP 180780 View Materials , 1 View Materials , 23.5 mm SL, Yanayaku Grande, tributary of río Urubamba, southeast of Quillabamba on road to Ollantaytambo , 12º59’49”S 72º32’06”W, 17 Jul 2004 GoogleMaps   . CAS 70077 View Materials , 15 View Materials , 27.5-81.5 mm SL, río de Santa Ana, creek entering middle río Urubamba at ca. 3000-3400 ft. elev., the farthest point reached by the Eigenmann’s on río Urubamba , ca. 12º52’S 72º43’W, 15 Nov 1918 GoogleMaps   .

MCZ

Museum of Comparative Zoology

CAS

California Academy of Sciences

Kingdom

Animalia

Phylum

Chordata

Class

Actinopterygii

Order

Characiformes

Family

Characidae

Genus

Hemibrycon

Loc

Hemibrycon helleri Eigenmann, 1927

Bertaco, Vinicius A. & Malabarba, Luiz R. 2010
2010
Loc

Hemibrycon helleri

Eigenmann 1927: 402
1927