Prochilodus rubrotaeniatus Jardine 1841

Potamodromous. Migrating within streams, migratory in rivers, e.g. Saliminus, Moxostoma, Labeo. Migrations should be cyclical and predictable and cover more than 100 km.

Biology poorly known. Lives in pairs downstream in rapidly flowing water over sandy bottoms (Ref. 12225).

Prochilodus rubrotaeniatus Jardine, 1841

Prochilodus rubrotaeniatus Jardine, 1841:258, pl. 28 [type locality: Rios Branco and Negro as in the Essequibo and its tributaries (=Brazil, Roraima, Rio Branco, Amazonas, Rio Negro; Guiana, Rio Essequibo and tributaries). Restricted herein to Rio Branco, Brazil, and Essequibo River, Guiana].—Valenciennes in Cuvier and Valenciennes, 1850:89 [based upon Jardine, 1841].—Gunther, 1866:30 [Amazon].—Eigenmann and Eigenmann, 1891:48 [in listing of South American fishes].—Eigenmann and Ogle, 1907:5 [cited similarity to P. beani]—Eigenmann, 1907b:768 [lateral-line scale count]; 1910:424 [in listing of South American fishes]; 1912:270 [British Guiana (=Guyana), Essequibo River]; 1922a:116 [comparison with Prochilodus steindachneri].—Cockrell, 1914:96 [scale morphology].—Eigenmann and Allen, 1942:309 [comparison with P. nigricans].—Fowler, 1945:124 [in part, not cited occurrence of species in Peru]; 1950:223 [literature compilation; in part, not reported occurrence of species in Peru]; 1975:360 [literature compilation].—Boeseman, 1952:184 [Suriname: Coppenam River, Lucie River; common name].—Lowe-McConnell, 1964:110 [Guyana, Rupununi District, north and south savannas of Essequibo River basin, Jacare River of Rio Amazonas basin]; 1984:143 [economic importance].—Fernández-Yépez, 1969: 55 [questionably cited as present in Venezuela, Rio Caroni].—Mago-Leccia, 1970:26 [Venezuela]; 1972, figs, 5c, 8 [redescription of species; Venezuela, Rio Cuyuni and Rio Caroni]; 1978:5 [Venezuela].—Géry, 1977:218 [in part, not citation from upper Amazon].—Le Bail et al., 1984:59 [French Guiana].—Ferreira et al., 1988:343 [Brazil, Roraima, Rio Mucujai].—Lasso et al., 1990: 141 [Venezuela, Lago de Guri].—Novoa et al., 1990:159 [Venezuela, Lago de Guri].—Menzes and Vazzoler, 1992:62 [reproductive characteristics].—Taphom et al., 1997:79 [Venezuela].—Wiliams and Winemiller, 1998:281 [Venezuela, Guri Reservoir; dominance of species in gill-net surveys].—Machado-Allison et al., 2000:17 [Venezuela, Rio Cuyuni, Raudal de Paruruvaca].—[Not Günther, 1864:295.]

Prochilodus cf. nigricans.—Goulding et al., 1988:129 [Brazil, Rio Negro].

Prochilodus nigricans [not of Agassiz, 1829].—Günther, 1864:295 [in part, Prochilodus rubrotaeniatus incorrectly placed as synonym of P. nigricans Agassiz, 1829; Guyana, Essequibo River].

Prochilodus maripicru Eigenmann, 1912:271, pl. 35: fig. 2 [type locality: British Guiana (=Guyana), Essequibo, Maripicru Creek, a branch of Ireng (River, Amazon basin)].—Boeseman, 1953:13 [Suriname, Marowini River basin; common name].—Mago-Leccia, 1972:47 [use of caudal-fin pigmentation to distinguish species groups].—Géry, 1977:219 [Guianas].—Ibarra and Stewart, 1987:70 [type depository].—[Not Ovchynnyk, 1971:105.]

Prochilodus reticulatus [not of Valenciennes, 1850].—Le Bail et al., 1984:59 [French Guiana].—Planquette et al., 1996:132 [western portions of Guyane (= French Guiana)].

Prochilodus cf. rubrotaeniatus.—Ferreira et al., 1988:343, table 1 [Brazil, Rio Branco basin].

DIAGNOSIS.—The dark, irregular, wavy, bar-like patterns on the caudal-fin lobes of Prochilodus rubrotaeniatus distinguishes that species from P. argenteus, P. britskii, P. costatus, P. hartii, P. lineatus, P. magdalenae, P. reticulatus, and P. vimboides, which have hyaline caudal fins. Within the group of Prochilodus species with dark caudal-fin markings, P. rubrotaeniatus differs from P. mariae in the number of scales along the lateral line (44 to 48 scales versus 52 to 64, respectively) and in the number of dark, wavy, horizontal stripes along the lateral surface of the body dorsal to the lateral line (3 to 5 versus 6 or 7, respectively); from P. lacustris in the form of the scales (with complex pattern of variable subdivisions versus having only radial subdivisions) and in the number of horizontal rows of scales between the pelvic-fin insertion and the lateral line (6 or 7, 6 most frequent, versus 8 to 11, 9 most frequent, respectively); from P. brevis in the form of the scales (with complex pattern of variable subdivisions versus having only radial subdivisions) and in the number of horizontal rows of scales between the pelvic-fin insertion and the lateral line (6 or 7, 6 most frequent, versus 6 to 8, 7 most frequent and 6 in only 2% of specimens examined for this feature, respectively); and from P. nigricans in the number of horizontal rows of scales around the caudal peduncle (14 to 18, with 16 most frequent and 17 and 18 in only 10.8% of specimens examined for this feature, versus 17 to 21, with 19 most frequent and 17 in only 0.9% of specimens examined for this feature, respectively; Figure 54), the number of horizontal rows of scales between the pelvic-fin insertion and the lateral line (6 or 7, 6 most frequent, versus 7 to 9, 8 most frequent, respectively; Figure 55), and the range and modal numbers of lateral-line scales (44 to 48 with 45 most frequent and 47 and 48 in only 10% of specimens examined for this feature, versus 44 to 51 with 49 most frequent and 44 to 46 in only 3.0% of specimens examined for this feature, respectively; Figure 56).

DESCRIPTION.—Morphometric and meristic data for Prochilodus rubrotaeniatus presented in Table 16. Body comparatively high, transversely compressed. Greatest body depth at dorsal-fin origin. Dorsal profile of head moderately concave. Predorsal profile of body convex. Body profile posteroventrally inclined along dorsal-fin base; profile straight from posterior of dorsal-fin base to adipose-fin origin, and concave along caudal peduncle. Predorsal portion of body with slight median ridge. Postdorsal portion of body obtusely rounded transversely. Ventral profile of body convex from tip of lower jaw to posterior of anal-fin base. Ventral profile of caudal peduncle concave. Prepelvic region transversely flattened proximate to pelvic-fin insertion. Distinct median keel present between pelvic-fin insertion and anus.

Head profile pointed. Mouth terminal. Snout length much greater than horizontal width of orbit. Nares of each side of head close to each other; anterior nares circular, posterior nares crescent shaped. A dipose eyelid present but poorly developed; most developed anteriorly, but with greater part of eye uncovered. Lips fleshy, moderately developed, and forming oral disk when protracted.

Functional teeth in two rows in each jaw. All teeth movably implanted in flesh that overlies jaws. All teeth of similar size and spoon shaped except when worn down. Inner tooth series with 16 to 23 teeth on left side of upper jaw and 9 to 13 teeth on left side of lower jaw. Outer row of teeth in each jaw with approximately 94 teeth on each side of upper jaw and approximately 87 teeth on each side of lower jaw in examined type specimens. Upper and lower lips bordered by numerous globular, fleshy papillae.

Scales spinoid. Scales in middorsal series between posterior of dorsal fin and adipose-fin origin similar in form to those of adjoining regions of body. Lateral line with 44 to 48 (41.2% of specimens with 46) pored scales; 7 to 9 (88.2% of specimens with 8) horizontal rows of scales between dorsal-fin origin and lateral line; 6 or 7 (55.9% of specimens with 6) horizontal rows of scales between pelvic-fin insertion and lateral line; 5 to 7 (74.3% of specimens with 6) horizontal rows of scales between anal-fin origin and lateral line; 13 to 17 (55.9% of specimens with 14) median predorsal scales; 14 to 18 (35.3% of specimens with 16) scales in middorsal series between posterior of dorsal-fin base and adipose-fin origin; 14 to 18 (32.4% of specimens with 16) horizontal rows of scales around caudal peduncle.

Dorsal fin preceded by small, but well-developed, anteroventrally bifurcate, procumbent spine somewhat triangular in lateral view. Dorsal-fin rays (including procumbent spine) iii, 7 to 10 (iii,7 very rare) [11 rays reported by Jardine in original description, a count that presumably includes both branched and unbranched rays]; anal-fin rays ii,8 or iii,8 (iii,8 most frequent) [10 rays reported by Jardine in original description, a count that presumably includes both branched and unbranched rays]; pectoral-fin rays i,13 to 16 (i,14 most frequent) [15 rays reported by Jardine in original description, a count that presumably includes both branched and unbranched rays]; pelvic-fin rays i,8 or 9 (i,8 most frequent) [9 rays reported by Jardine in original description, a count that presumably includes both branched and unbranched rays]; principal caudal-fin rays 10/9.

Vertebrae 41 or 42 (60.0% of specimens with 41) [40 vertebrate reported by Jardine in original description; see “Remarks”].

Dorsal fin truncate, slightly pointed distally; posterior unbranched and anterior branched rays longest. Dorsal-fin origin located closer to tip of snout than to caudal-fin base. Greatest length of adipose fin approximately equal to horizontal width of orbit. Adipose-fin origin located along vertical that passes through anterior one-third of length of anal-fin base. Pectoral fin pointed distally. Tip of adpressed pectoral fin reaching, or almost reaching, pelvic-fin insertion. Pelvic fin falcate. Pelvic-fin insertion located along vertical that passes through anterior one-third of dorsal-fin base. Tip of adpressed pelvic fin reaching approximately two-thirds of distance between pelvic-fin insertion and anus. Axillary scale present, its length approximately one-fourth of greatest length of pelvic fin. Posterior unbranched and anterior branched anal-fin rays longest and subequal. Caudal fin moderately bifurcate.

COLORATION IN ALCOHOL.—Ground coloration silvery yellow or brownish yellow, with dorsal portion of body and head darker. Lateral surface of body with 10 to 24 dark, vertically elongate, diffuse, and irregular patches of pigmentation between head and caudal fin. Patches with approximate overall form of narrow isosceles triangles, with apex located along middle of ventrolateral portion of body and base on dorsomedial region of body. Pigment patches well developed in small specimens, but indistinct or absent in large individuals. Lateral surface of body with approximately 8 to 12 dark, wavy, horizontal stripes along dorsal and ventral margins of exposed portions of scales. Approximately 3 to 5 (most frequently 4) wavy stripes dorsal to, and 5 to 7 (most frequently 6) wavy stripes below, lateral line. Field of black or brown chromatophores forming dark, irregular spot on upper one-half of opercle.

Dorsal fin with 4 to 10 (most frequently 5) dark irregular stripes beginning on anterior margin of fin and extending across fin approximately parallel to base of fin. Adipose fin with dorsal margin finely bordered with black. Pectoral, pelvic, and anal fins dusky. Caudal fin with 2 to 5 (most frequently 3) irregular vertical bars and wavy patterns formed of small dark spots made of groups of chromatophores. Iris yellowish silver or brownish silver, with diffuse, dusky dorsal and ventral regions.

COLORATION IN LIFE.—(Based upon a photo of what is apparently a specimen in an aquarium published in Planquette et al. (1996:133) that was identified by those authors as Prochilodus reticulatus. See comments under “Remarks,” below, concerning that identification). Overall coloration silvery, more so on ventral portions of head and body, somewhat more dusky dorsally, particularly on dorsal portion of head. Dark pigmentation along scale margins forming irregular horizontal stripes along ventral portions of body. Pelvic fin, distal portions of anal fin, and posterior margin of lower lobe of caudal fin with reddish cast. Upper portion of operculum yellowish. According to Lasso et al. (1990:151), P. rubrotaeniatus is light brown with a yellowish coloration in life.

DISTRIBUTION.—Examined specimens of Prochilodus rubrotaeniatus originated in the Rio Branco and Rio Marauiá basins, Brazil, and in coastal rivers of Guyana, Suriname, and French Guiana (Figure 52, diamonds). Mago-Leccia (1972:57), Lasso et al. (1990:151), Williams and Winemiller (1998:281), and Machado-Allison et al. (2000:17) also reported the species as occurring in Venezuela in the Río Cuyuni and Río Caroni basins.

COMMON NAME.—Curimatá (Brazil), Bocachica de Guianas (Venezuela); coulitata, courimata, colmata, coumata, koulimata, koumata (French Guiana); koonoomatta, alumassee (Suriname).

COMPARISONS.—The combination of differences in pigmentation and various meristic features unequivocally discriminate Prochilodus rubrotaeniatus from all of its congeners with the exception of P. nigricans. Prochilodus rubrotaeniatus and P. nigricans have allopatric distributions (Figure 52) and apparently inhabit different water types (black and clear waters versus white waters, respectively). Furthermore, the two species have minimal overlap in the number of horizontal rows of scales around the caudal peduncle (Figure 54), differ modally in the number of horizontal rows of scales between the pelvic-fin insertion and lateral line (Figure 55), and differ in the number of lateral-line scales (Figure 56). The two nominal forms are consequently herein recognized as distinct species.

MATERIAL EXAMINED.—130 specimens (32, 69.9–320.8 mm SL; partial meristic data taken from 40 additional specimens).

BRAZIL. Amazonas: Rio Marauiá, beach at Cachoeira do Bicho-Açu (0°20′S, 65°20′W), USNM 233849, 1 (1, 107.7) [1R]. Roraima: Rio Mucajaí, S of Boa Vista, MZUSP 20722, 2 (2, 101.5–126.4).

GUYANA. Essequibo: quiet water area in stream with sandy bottom, Rupununi River, BMNH 1972.7.27:424–426, 3 (1, 217.0–288.0). Kasuero Karanambo, Pirara Stop-off, along margin of Takatu River (Rio Amazonas basin), BMNH 1972.7.27:428–430, 3 (1, 164.4–227.6) [1R]. Kbo, Rupununi River (Essequibo River basin), BMNH 1972.7.27:431–434, 4 (1, 109.2–214.5) [1R]. Cajuero, Rupununi River, BMNH 1972.7.27: 420–423, 4 (2, 72.2–78.9). Pond 3 mi [4.8 km] N of Yapukarri, Rupununi River, MCZ 48543, 1 (1, 120.9) [1R]. Small pond 5 mi [8 km] N of Manari Ranch, MCZ 48542, 1 (1, 106.8) [1R]. Rockstone, Essequibo River, AMNH 14436, 1 (1, 99.2) [1R]. Sandbar in Rockstone, Essequibo River, CAS 59314 (formerly IU 12254), 3 (1, 195.6–222.3) [1R]. Essequibo River, BMNH uncatalogued, 1 (1, 173.3) [1R]; MNHN 6266, 1 (280.4). Sandbar along N shore of Cuyuni River, directly W of Caouri (Caowry) Creek, AMNH 72138, 4 (1, 144.0–177.2) [1R]. Sandbar along N shore of Cuyuni River, immediately upriver of Caouri (Caowry) Creek, AMNH 72138, 4 (143.9–174.3); AMNH 73004, 1 (1, 103.4) [1R]. Creek near Penal Settlement, Mazaruni River, BMNH 1934.9.12:348–350, 3 (3, 110.7–320.8). Manari River, Manari Ranch, near Lethem, CAS 16068, 1 (100.0) [1R]. Maripicru Creek, branch of Ireng River, FMNH 53597, 1 (1, 236.2, holotype of Prochilodus maripicru, formerly CM 2066) [1R]. Inexact Locality: Sandbar in Maxiprica, CAS 59315, 1 (1, 165.5) [1R].

FRENCH GUIANA. Cayenne: Fleuve Oyapock, Rapides Trois Sauts (2°15′N, 52°53′W), MNHN 1981–398, 1 (1, 120.9).

SURINAME. Marowijne: Litani and Oelemari Rivers, AMNH 16405, 1 (1, 302.1) [1R]. Nickerie: N shore tributary to Sisa Creek, approximately 700 m upriver of crossing of road between Amotopo and Camp Geology (3°42′N, 57°42′W, USNM 225384, 8 (1, 72.1–90.8) [1R]. Stream at km 212 along road from Amotopo to Camp Geology, in Machine Park (3°50′N, 57°34′W), USNM 225418, 1 (1, 141.3) [1R]. Kamp Kreek, 100 m N of turnoff to Camp Geology (44°9′N, 057°28′W), USNM 225385, 14 (1, 76.1–91.3) [1R]. Corantjin River at km 180, side channel of main river along Surinamese shore (5°08′N, 57°18′W), USNM 225419, 27 (4, 69.9–150.4). Pool in front of Camp Hydro (3°42′N, 57°58′W), AMNH 54936, 4 (79.0–122.6); USNM 225322, 1 (1, 91.2) [1R]. Streams entering Corantjin River at approximately km 385, slightly N of Tiger Falls (4°00′N, 58°02′W), USNM 225323, 1 (1, 81.0) [1R]. Corantijn River, BMNH 1981.6.9:814–815, 2 (1, 102.5–105.0). Kapoeri Creek, approximately 7 km from junction with Corantijn River, AMNH 45770, 13 (77.6–107.8). Stream near Camp Avanavero, approximately 3 mi (4.8 km) downstream of De Vis Falls, AMNH 54845, 17 (89.0–108.6).