Hemibrycon jelskii ( Steindachner, 1877 )

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. 737-770 : 749-752

Hemibrycon jelskii ( Steindachner, 1877) Figs. 12-13

Tetragonopterus jelskii Steindachner, 1877: 40-42 (original description, type locality: Monterico in Peru [Monterrico, Department of Ayacucho, río Ucayali drainage, Peru]).

Hemibrycon jelskii . -Eigenmann, 1910: 432 (listed).

Diagnosis. Hemibrycon jelskii is distinguished from all congeners, except H. helleri , by the size of humeral spot (over 7-9 vs. 3-6 horizontal series of scales). It differs from H. helleri by the number of branched anal-fin rays (25-30 vs. 19-23, Fig.2 ), and by the number of scales along anal-fin base scale sheath (13-28 vs. 6-12). Hemibrycon jelskii is rather similar to H. divisorensis , but can be distinguished by the absence of a wide black asymmetrical spot covering base of caudal-fin rays and black band in the lower half of the caudal peduncle (vs. presence), and by the number of scale rows above and below lateral line (7-9 and 5-7 vs. 6-7 and 4-5, respectively).

Description. Morphometric data for H. jelskii summarized in Table 3. Largest male 77.9 mm SL, largest female 101.7 mm SL. Body compressed and moderately elongate; greatest body depth at vertical through middle length of pectoral fins. Dorsal profile of head nearly straight to slightly convex, and slightly concave in the occipital region. 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 anal-fin origin. Body profile along anal-fin 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 below 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 3-6, tri- to pentacuspid teeth with central cusp slightly longer; inner row with 4 pentacuspid 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 8-17 uni- to tricuspid teeth, with central cusp longer. Three anteriormost dentary teeth larger, with 5-7 cusps, followed by medium sized tooth with 3-5 cusps, and 8-10 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. 13 ).

Dorsal-fin rays ii,8 (n = 224); first unbranched ray approximately one-half length of second ray. Dorsal-fin origin located approximately to middle of SL and posterior to vertical through pelvic-fin origin. Males with bony hooks in distal one-third of first branched rays. Profile of distal margin of dorsal fin nearly straight to slightly concave. Adipose-fin located at vertical through insertion of last anal-fin rays. Analfin rays iii-v,25-30 (mode = 27, n = 224, Fig. 2 ). Anal-fin profile slightly concave 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 bony hooks along posterolateral border of each segment of lepidotrichia, along last unbranched ray and all branched rays, usually to fifth branched rays. Hooks usually located along posteriormost branch and distal 1 / 2 to 2 / 3 of each ray. Pectoralfin rays i,10-13 (mode = 11, n = 224). 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 or i,7 (n = 224). Pelvic-fin origin located 6-7 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 all branched rays. Caudal fin forked with 19 principal rays (n = 224). Caudal-fin base with few scales. Dorsal procurrent rays 10-13 and ventral procurrent rays 10-13 (n = 16).

Scales cycloid, moderately large. Lateral line complete with 40-43 (mode = 41, n = 221, Fig. 3). Scale rows between dorsalfin origin and lateral line 7-9 (mode = 8, n = 224); scale rows between lateral line and pelvic-fin origin 5-7 (mode = 6, n = 224). Predorsal scales 13-17, arranged in regular series (mode = 14, n = 218). Scales rows around caudal peduncle 16 (n = 220). Axillary scale on pelvic-fin origin extends posteriorly covering 2-3 scales. Scale sheath along anal-fin base with 13-28 scales in single series, extending to base of most branched rays.

Precaudal vertebrae 16-18; caudal vertebrae 21-23; total vertebrae 38-40 (n = 21). Supraneurals 6-8 (n = 22). Gill rakers on upper limb of outer gill arch 7-9, and on lower limb 12-14 (n = 26).

Color in alcohol. General ground body color brown yellowish. Dorsal portion of head and body with concentration of black chromatophores. Dorsolateral portion of head and body with scattered black chromatophores. One vertical black humeral spot, located over fourth to sixth lateral line scales and extending over 7-9 horizontal series of scales, including lateral line. Midlateral stripe silvery. Midlateral dark stripe extending from humeral region to middle caudal-fin rays, broad in the caudal peduncle. Abdominal region almost devoid of black chromatophores. Dorsal and caudal fin with black pigmentation diffuse and anal fin with small black chromatophores along its border forming narrow stripe. Pectoral, pelvic and adipose fins hyaline ( Fig. 12 ).

Sexual dimorphism. Males of Hemibrycon jelskii are easily recognized by the presence of bony hooks in dorsal-, anal-, pelvic- and pectoral-fin rays. Males and females also slightly differ in pectoral- and pelvic-fin lengths and body depth ( Table 3), and in anal-fin shape, slightly concave in males and nearly straight in females. Mature males with gill gland on first gill arch, covering the first branchial filaments ( Fig. 7 ).

750 A review of the Cis-Andean species of Hemibrycon

Distribution. Hemibrycon jelskii is widespread in the upper portions of río Marañon, río Ucayali, and headwater rivers of río Madeira-Mamoré drainages in Bolivia, Brazil and Peru ( Fig. 4 ).

Remarks. The specimens on which Steindachner (1877: 42) proposed Tetragonopterus jelskii were collected at “Monterico”, Peru by Prof. Jeslki. According to Stephens & Traylor (1983: 137), the exact site of the locality reported by Taczanowski (1884: 73) as “Monterico” has been the subject of differing opinions. Stephens & Traylor (1983) suggest that the type locality is probably Monterrico (ca. 12º28’S 73º54’W) in the Department of Ayacucho, Peru. The river or basin next this locality is the río Apurimac that belong the río Ucayali drainage, and not río Remac drainage near Lima as reported in Lima et al. (2003: 130). We analyzed eleven specimens of the 22 syntypes deposited in the NMW. The specimens are relatively in good condition and only one specimen examined had the caudal-fin broken.

Geographic variation. Several population samples of H. jelskii were examined during this study from upper portions of the río Marañon and río Ucayali drainages, and upper tributaries of the río Madeira-Mamoré drainage. Hemibrycon jelskii possesses a larger number of maxillary teeth (8-17) and scales along anal-fin base scale sheath (13-28), and a larger humeral spot (7-9 horizontal series of scales) among Hemibrycon species.

All these specimens fit within the range of meristic and morphometric data of the syntypes examined, except the orbital diameter. The orbital diameter of syntypes is smaller than that found in all population samples of the species, but this seems to be related to the large body size of the type specimens ( Table 3). Among 11 syntypes analyzed, nine are larger than 70 mm SL. No significant differences in counts were found between the examined populations of H. jelskii .

The population from the río Beni has a slightly larger head length and orbital diameter compared with syntypes, but overlapping with the ranges observed in population samples from the río Ucayali, type locality of the species. This difference is due to distinct standard length of specimens between populations. The río Chapare population has a prepectoral distance slightly larger than that observed in the syntypes, but when compared with the río Ucayali population this difference disappear ( Table 3) .

Material examined. Syntypes. NMW 57548, 2 (x-ray), 99.7- 101.7 mm SL ; NMW 57551, 4 (x-ray), 57.0- 68.5 mm SL ; NMW 57554, 5 (x-ray), 69.4-90.6 mm SL, río Ucayali drainage, ca. 12º28’S 73º54’W, Monterrico, Department of Ayacucho, Peru . Non-type specimens. Peru. Río Ucayali drainage: ANSP 143281 , 2 , 41.9 -

V. A. Bertaco & L . R. Malabarba 751 43.5 mm SL, río Tono at Hacienda San Jorge , 4 km W on road from Patria , Cusco, ca. 12º53’S 71º27’W, 17 Jul 1977 . ANSP 143282 , 1 , 32.5 mm SL, mouth of río Carbon, below Atalaya on N/S road, Cusco-Madre de Dios, ca. 12º53’S 71º20’W, 18 Jul 1977 . ANSP 143285 , 1 , 41.3 mm SL, near Atalaya, N bank tributary of río Carbon ca. 3 km upstream from Huacarpay-Shintuya Road ford, Madre de Dios-Cusco , ca. 12º54’S 71º21’W, 18 Jul 1977 . ANSP 143274 , 1 , 42.6 mm SL ; ANSP 143286 , 1 , 79.8 mm SL ; ANSP 143288 , 3 , 46.8-82.8 mm SL ; ANSP 143289 , 2 , 42-84.4 mm SL, río Hospital ca. 2 km W of Patria on N/S road, Cusco, ca. 12º53’S 71º20’W, 14-15 Jul 1977 . ANSP 180772 , 1 , 68.6 mm SL, río Igoritoshiari, río Urubamba drainage, road crossing north of Kiteni , Cusco, 12º26’56”S 73º00’59”W, 21 Jul 2004 . MUSM 2958 , 4 of 6, 52.6-63.8 mm SL, río Huacamayo, Aguaytía, Padre Abad , Ucayali, ca. 09º02’S 75º30’W, 24 Nov 1983 . MUSM 17261 , 20 of 62, 26.5- 46.6 mm SL, río Urubamba, Shepahua , Ucayali, ca. 11º10’S 73º00’W, 6 Jun 1998 . MUSM 19562 , 20 of 64, 46.1-69.0 mm SL, middle portion of quebrada John, río Pacuya, Cordilheira Azul Norte , Ucayali, Loreto, ca. 07º20’S 75º40’W, 24 Aug 2000 . Río Marañon drainage: MUSM 2166 , 10 of 25, 54.2-81.9 mm SL, tributary of río Huancabamba , between Pucará and Guabel, Jaen, Cajamarca, ca. 05º56’S 79º15’W, 9 Jul 1986 . MUSM 19145 , 20 of 70, 38.9-67.9 mm SL, quebrada Chumab , CCNN Paski, río Cenepa , CCA río Marañon, Condarcanqui , Amazonas, 04º33’05”S 78º11’03”W, 25 Sep 2001 . MUSM 21343 , 20 of 82, 33.9-60.4 mm SL, quebrada Capitán Ponce , CCA río Alto Cenepa, Cenepa, Condarcanqui , Amazonas, 03º47’28”S 78º22’19”W, 15 Nov 2003 . ROM 52240, 50 of 205 (3 c&s), 25.1-87.8 mm SL, ca. 74 km W of road going N to Jean, between Pucara and Guabel , Huancabamba river tributary, 05º56’00”S 79º15’00”W, 8 Jul 1986 . Río Madre de Dios drainage: ANSP 143275 , 1 , 30.0 mm SL, río Alto Madre de Dios, ca. 15 km upstream from Boca Manu, Madre de Dios, ca. 12º19’S 70º58’W . ANSP 143277 , 24 (3 c&s), 22.7-35.8 mm SL, Pilcopata River , wire ferry, 3 km above Pilcopata, Cusco, 12º56’30”S 71º24’00”W, 16 Jun 1977 . ANSP 143278 , 1 , 39.4 mm SL, at Shintuya, río Alto Madre de Dios, Madre de Dios, ca. 12º40’S 71º11’W, 1-3 Aug 1977 . ANSP 180778 , 1 , 71.3 mm SL, río Nusiniscato, río Inambari drainage, road crossing between Quince Mil and Pto. Leguia, Cusco, 13º11’17”S 70º34’05”W, 26 Jul 2004 . ANSP 180779 , 3 , 38.1 -45.0 mm SL, río Inambari and mouth of quebrada Hondonado, upstream of Puerto Mazuko , Cusco, 13º06’23”S 70º24’44”W, 27 Jul 2004 . CAS 70386, 11 of 18, 70.5-90.4 mm SL, tributary to río Tambopata at Pampa Grande , ca. 12 mi below San Ignacio, ca. 3,000 ft. elev., Puno, ca. 14º05’S 69º00’W, 5 Nov 1951 . MUSM 3759 , 8 of 25, 43.9-85.0 mm SL, quebrada Culli, upper río Madre de Dios, Erika, Manu , Madre de Dios, ca. 12º10’S 71º00’W, 5 Sep 1988 . MUSM 11080 , 8 of 11, 36.6-78.6 mm SL, quebrada Ebebahuaeji, río Candamo, Sandia , Puno, 13º14’56”S 70º00’35”W, 31 Mar 1997 . MUSM 24302 , 10 of 22, 26.5-37.3 mm SL, río Amiguillos, río Loa Amigos, Manu , Madre de Dios, 12º25’37”S 70º17’33”W, 18 Jun 2004 , M. Hidalgo et al. MUSM 26409 , 20 of 66, quebrada Yanamayo, Quincemil, río Araza drainage, Camanti , Quispicanchi , Cusco, 13º16’54”S 70º47’04”W, 21 Oct 2005 . MUSM 26776 , 2 of 8, 79.6-88.3 mm SL, río Araza drainage, San Lorenzo, Camanti , Quispicanchi , Cusco, 13º13’05”S 70º31’39”W, 25 Oct 2005 . MUSM 26785 , 20 of 53, 36.8-96.9 mm SL, quebrada Ilahuala, río 752 A review of the Cis-Andean species of Hemibrycon

Araza drainage, San Lorenzo, Camanti, Quispicanchi, Cusco, 13º13’02”S 70º31’48”W, 25 Oct 2005. ROM 66370, 9 , 39.2-57.2 mm SL, Tambopata-Candamo Reserved Zone, Puno, left bank, large stream, 13º21’02”S 69º38’58”W, Tavara River tributary, 17 Aug 1992 . Bolivia. Río Beni drainage : CAS 70079, 11 , 46.9-82.2 mm SL, río Popoi , a tributary of upper río Beni, Beni, Sep 1921 . CAS 70081, 18 , 30.3 -46.0 mm SL, 30 miles northwest of Rurrenabaque , Tumapasa, La Paz, ca. 14º10’S 67º30’W, Dec 1921 . MNHN 1989.1417 , 2 , 50.7-59.1 mm SL, río San Juanito , Yacuma, Beni, ca. 15º10’S 67º04’W, Jul 1982 . Río Chapare drainage : MCP 35019, 17 , 42.1-66.8 mm SL, arroyo del Hotel el Puente, Villa Tunari, Chapare , Cochabamba, 16º59’06”S 65º24’45”W, 10 Nov 2003 . MCP 35020 4, 37.4-57.7 mm SL, río Espiritu Santo, Villa Tunari, Chapare, Cochabamba, 16º58’20”S 65º24’48”W, 14 Sep 2002 . MCP 35021, 10 , 40.1-63.5 mm SL, río Espirito Santo, Chocolatal, Chapare, Cochabamba, 17º03’51”S 65º38’50”W, 20 Feb 2003 . MCP 35022, 21 , 36.3 -46.0 mm SL, río Chipiriri , Chipiriri, Chapare, Cochabamba, 16º53’33”S 65º24’44”W, 20 Sep 2002 . MNHN 1989.1418 , 20 , 35.3- 75.5 mm SL, río Espirito Santo, Villa Tunari, Cristal Mayu , ca. 17º03’S 65º38’W, Jun 1983 , L. Loubens. MZUSP 27827 , 4 , 53.7 - 73.0 mm SL, río Espirito Santo, Villa Tunari, Cristal Mayu , ca. 17º03’S 65º38’W, 24 Jun 1983 . Brazil, rio Guaporé drainage : MCP 37754, 5 , 26.0- 36.1 mm SL, affluent of rio Galera , Pontes e Lacerda, Mato Grosso, 14º39’12”S 59º26’46”W, 12 Jul 2004 . MCP 38177, 67 (5 c&s), 18.0- 42.4 mm SL, stream Retiro at road BR 174 , tributary of rio Guaporé , Nova Lacerda, Mato Grosso, 14º48’07”S 59º19’24”W, 12 Jul 2004 .

Figures

Fig. 12. Hemibrycon jelskii, MUSM 19562, male, 69.0 mm SL, upper río Ucayali basin, Peru.

Fig. 13. Hemibrycon jelskii, MUSM 19562, male, 52.1 mm SL. Scanning electron micrograph of left side upper and lower jaws. Scale bar = 1 mm.

Fig. 2. Tukey box plots of number of branched anal-fin rays in Hemibrycon species. Mean represented by thick vertical bar, and 25th and 75th percetiles as lateral borders of box plots. Number in parentheses = N.

Fig. 7. First gill arch showing gill gland. Lateral view of the left side of (a) Hemibrycon helleri,ANSP 180775, (b) Hemibrycon metae, USNM 228563; (c) Hemibrycon huambonicus, USNM 086794; (d) Hemibrycon jelskii, MCP 35022. Scale bars = 1 mm.

Fig. 4. Map of central and northern South America showing geographic distribution of Hemibrycon beni (1, solid hexagon), H. divisorensis (2, open triangle), H. helleri (3, ellipse), H. huambonicus (4, solid triangles), H. jelskii (5, solid dots), H. inambari (6, rectangles), H. metae (7, solid squares), H. mikrostiktos (8, open square), H. polyodon (9, inverted triangle), H. surinamensis (10, solid diamonds), H. taeniurus (11,Trinidad Island), H.tridens (12, open circle).Some symbols represent more than one lot or locality of specimens. 1-12 = type locality of each species.