Cyphocharax gouldingi Vari 1992

Cyphocharax gouldingi

DIAGNOSIS.—Cyphocharax gouldingi is distinguished from its congeners by the combination of 30 to 33 lateral-line scales to the hypural joint, the completely pored laterosensory canal system on the body, the 31 or 32, typically 31 vertebrae, the relative body depth (0.38–0.42 of SL), the relative depth of the caudal peduncle (0.12–0.14 of SL), the relative length of the postorbital portion of the head (0.34–0.40 of HL), the relative length of the head (0.27–0.31 of SL), the relative width of the orbit (0.32–0.38 of HL), the absence of multiple series of longitudinal dark stripes or small dark spots in longitudinal rows on the body, the absence of a discrete patch of dark pigmentation on the dorsal fin, the presence of a rotund patch of dark pigmentation about one-half the diameter of the orbit on the midlateral surface of the caudal peduncle not preceded by 4 or 5 large midlateral dark spots on the body, the absence of a stripe of dark pigmentation across the middle rays of the caudal fin in moderate to large-sized specimens, the lack of a reticulate pattern on the body in adults, and the possession of 9 branched dorsal-fin rays.

Cyphocharax gouldingi is very similar in morphometric and meristic features to C. helleri and C. microcephalus that also occur in the Guianas and adjoining areas. Cyphocharax gouldingi and C. helleri are sympatric at least in the Rio Cupixi system of Amapá state, Brazil. The two species are readily distinguished by the series of dark horizontal stripes along the lateral surface of the body in C. helleri that are absent in C. gouldingi (compare Figures 17 and 81). Cyphocharax gouldingi and C. microcephalus which have allopatric distributions, differ in the relative length of the postorbital portion of the head (0.34–0.40 of HL in C. gouldingi versus 0.42–0.47 in C. microcephalus) and in the absence in C. microcephalus of the large rotund spot of dark pigmentation on the midlateral surface of the caudal peduncle that occurs in C. gouldingi. They also differ, but less discretely, in the relative depth of the caudal peduncle (0.12–0.14 of SL in C. gouldingi versus 0.14–0.16 in C. microcephalus).

DESCRIPTION.—Body moderately elongate, somewhat compressed laterally. Dorsal profile of head slightly convex from tip of snout to vertical line through posterior nares, straight or very slightly convex from that line to tip of supraoccipital spine. Dorsal profile of body smoothly convex from tip of supraoccipital spine to origin of dorsal fin; straight and posteroventrally slanted at base of dorsal fin, straight or gently convex from base of last dorsal-fin ray to caudal peduncle. Dorsal surface of body with indistinct median keel immediately anterior to dorsal fin, smoothly rounded transversely posterior to fin. Ventral profile of body gently curved from tip of lower jaw to caudal peduncle. Prepelvic region transversely flattened, with obtuse lateral keels proximate to origin of pelvic fins, with irregular median series of scales. Median scale series proximate to origin of pelvic fins flanked on each side by series of scales that conform in shape to obtuse lateral angles of body wall. Scales of prepelvic region approximately of same size as on adjoining ventrolateral portions of body. Obtuse median keel posterior to pelvic-fin origin. Secondary obtuse keel on each side of postpelvic portion of body one scale dorsal of ventral midline.

Greatest body depth at origin of dorsal fin, depth 0.38–0.42 [0.42]; snout tip to origin of dorsal fin 0.50–0.54 [0.54]; snout tip to origin of anal fin 0.82–0.88 [0.87]; snout tip to origin of pelvic fin 0.55–0.59 [0.59]; snout tip to anus 0.79–0.84 [0.84]; origin of dorsal fin to hypural joint 0.55–0.60 [0.57]. Distal margin of dorsal fin straight or with anterior rays slightly longer; anterior branched rays two and three-quarters to slightly over three times length of ultimate ray. Pectoral fin pointed in profile; length of pectoral fin 0.20–0.25 [0.23], extends approximately to vertical line through origin of dorsal fin, about three-quarters of distance to origin of pelvic fin. Pelvic fin pointed in profile; length of pelvic fin 0.21–0.26 [0.24], reaches to or falls slightly short of anus. Caudal fin forked. Adipose fin well developed. Anal fin emarginate, last unbranched and first branched rays about two and one-half times length of ultimate ray. Least depth of caudal peduncle 0.12–0.14 [0.12].

Head somewhat pointed anteriorly in lateral profile; head length 0.27–0.31 [0.31]; upper jaw longer than lower, mouth subterminal; snout length 0.27–0.32 [0.28]; nares of each side very close, anterior circular, posterior crescent-shaped with aperture partially closed by thin flap of skin separating nares; orbital diameter 0.32–0.38 [0.36]; adipose eyelid present, more developed anteriorly, with vertically ovoid opening over center of eye; length of postorbital portion of head 0.34–0.40 [0.36]; gape width 0.22–0.28 [0.25]; interorbital width 0.41–0.46 [0.42].

Pored lateral-line scales from supracleithrum to hypural joint 30 to 33 [31]; all scales of lateral line pored, canals in lateral-line scales straight; 3 or 4 series of pored scales extends beyond hypural joint onto caudal-fin base; 5 to 6 (6 rare) [5] scales in transverse series from origin of dorsal fin to lateral line; 4 or 5 (5 rare) [4] scales in transverse series from lateral line to origin of anal fin.

Dorsal-fin rays ii,9 or iii,9 (when three unbranched rays present, first very short) [iii,9]; anal-fin rays ii,7 or iii,7 (when three unbranched rays present, first very short) [ii,7J; pectoral-fin rays 13 to 16 [16]; pelvic-fin rays i,8 or i,9 (i,9 in one specimen) [i,8].

Total vertebrae 31 (33), 32 (1).

COLOR IN ALCOHOL.—All specimens in type series retaining some guanine on scales, somewhat silvery to golden, darker on dorsal portions of head and body. Upper lip, snout, dorsal portion of opercle, and dorsal surface of head dark; head otherwise without distinct dark pigmentation. Scales on dorsal and dorsolateral surfaces of body outlined by varyingly developed darker pigmentation. Deep-lying midlateral stripe extending approximately from vertical line through origin of dorsal fin to caudal peduncle; stripe masked to varying degrees in specimens retaining guanine on midlateral surface of body. Dark rotund spot of dark pigmentation on midlateral surface of caudal peduncle; intensity of dark pigmentation in spot varies among individuals. Less intense fields of small dark chromatophores extending from dorsal and ventral margins of midlateral spot to dorsal and ventral margins of caudal peduncle; that secondary pigmentation absent in some individuals, most notably larger specimens from the Rio Capim system of northeastern Pará state in Brazil (MZUSP 20800). Dorsal and caudal fins dusky, with fin rays outlined by series of small dark chromatophores. Adipose and anal fin hyaline to dusky, latter fin with fin rays outlined by dark chromatophores when dusky. Pectoral and pelvic fins hyaline.

DISTRIBUTION.—Rivers of state of Amapá, and Rio Capim, Rio Tocantins, and lower Rio Xingu in state of Pará, Brazil (Figure 80).

ETYMOLOGY.—Named after Dr. Michael Goulding, collector of the type series, who has contributed greatly to our knowledge of the life history of many Amazonian species, and whose collecting efforts have resulted in large series of valuable specimens.

TYPE MATERIAL EXAMINED.—27 specimens (27, 62.3–86.9).

HOLOTYPE.—BRAZIL. Amapá: Rio Cupixi, along road to Serra Navio, mouth of rainforest stream (approx. 0°40′N, 51°40′W), collected by M. Goulding et al., Jan 1984; MZUSP 41762, 1 (86.7).

PARATYPES.—BRAZIL. Amapá: Rio Cupixi, along road to Serra Navio, mouth of rainforest stream (approx. 0°40′N, 51°40′W), collected by M. Goulding et al., Jan 1984, 26 specimens collected with holotype: USNM 268010, 13 (62.3–85.0; 1 specimen cleared and counterstained for cartilage and bone); MZUSP 41763, 13 (63.8–86.9).

NON-TYPE MATERIAL EXAMINED.—236 specimens (57, 47.3–112.2).

BRAZIL. Amapá: Rio Cupixi, along road to Serra do Navio, river channel (approx. 0°40′N, 51°40′W), USNM 267999, 10 (5, 76.8–84.3). Rio Cupixi, along road to Serra Navio, mouth of rainforest stream (approx. 0°40′N, 51°40′W), USNM 267998, 12 (8, 70.8–85.4). Rio Amapá, Cachoeira Grande, forest pool (approx. 2°10′N, 51°0′W), USNM 268006, 15 (7, 70.7–112.2). Pará: Rio Itacaiuna, Seira dos Carajás, Igarapé do Pojuca (approx. 5°30′S, 50°30′W), USNM 268009, 10 (5, 72.3–87.3); USNM 267992, 48 (10, 100.2–108.2). Rio Itacaiunas, Cachoeira Carreira Comprida (approx. 5°30′S, 50°30′W), USNM 268003, 4. Rio Xingu, Belo Monte, rocky pool (approx. 3°10′S, 51°50′W), USNM 268004, 25 (10, 47.3–56.6). Rio Apeú, Boa Vista, Município de Castanhal (Rio Capim system), MCZ 46114, 96 (6, 59.7–66.7); USNM 314608, 6 (58.3–69.7). Igarapé Apeú, Boa Vista, MZUSP 20800, 10.

Cyphocharax gillii (Eigenmann and Kennedy)

Curimatus gillii Eigenmann and Kennedy, 1903:510 llype locality: Paraguay: Arroyo Tremintina).—Vari, 1989a, tables 2, 3 [assigned to Cyphocharax].

Curimatus gilli.—Eigenmann, 1910:421 [reference].—Bertoni, 1914:9 [Paraguay].

Curimatella rehni Fowler, 1932:343, fig. [type locality: Brazil: Malo Grosso, Descalvados]; 1950:297, fig. 358 [literature compilation].—Ringuelet, 1975:72 (Río Paraguay system].—Vari, 1989a, tables 2, 3 [assigned to Cyphocharax]. [New synonymy.]

Curimata gillii.—Pearson, 1937:109 [Paraguay].—Fowler, 1950:285 [literature compilation].—Ringuelet, 1975:72 [Río Paraguay system].—Géry et al., 1987:416, fig. 35 [in part, specimens from Paraguay: Concepcion, Laguna Negra, Estancia Laguna Negra; Riacho Postillon; not specimens from marécages (swamps) N of Coronel Oviedo].

Curimata gilli.—Bertoni, 1939:54 [Paraguay].

Apolinarella rehni.—Fernández-Yépez, 1948:22 [assignment to Apolinarella].—Fowler, 1975:363 [reference].

Rivasella gilli.—Fernández-Yépez, 1948:57 [assignment to Rivasella].

Rivasella gillii.—Fowler, 1975:374 [reference].

Cyphocharax cf. gillii.—Venere and Galetti, 1989:20, 21 [Brazil: Mato Grosso, Rio Paraguay basin, Rio Bento Gomes near Poconé; cytotaxonomy].

DIAGNOSIS.—Cyphocharax gillii can be distinguished from its congeners by the combination of 28 to 33 lateral-line scales to the hypural joint, the development of the pores along the entire lateral line in all but juveniles, the 29 to 31, typically 30 vertebrae, the relative body depth (0.36–0.45 of SL), the relative depth of the caudal peduncle (0.13–0.15 of SL), the relative length of the postorbital portion of head (0.36–0.42 of HL), the relative length of the head (0.28–0.33 of SL), the relative width of the orbit (0.30–0.37 of HL), the absence of multiple series of longitudinal dark stripes or small dark spots in longitudinal rows on the body, the absence of a discrete patch of dark pigmentation on the dorsal fin, the presence of a rotund patch of dark pigmentation about equal in size to diameter of the orbit on the midlateral surface of the caudal peduncle with an irregular border reaching to the dorsal and ventral margins of the caudal peduncle in juveniles, the absence of 4 or 5 large midlateral dark spots on the body, the absence of a stripe of dark pigmentation across the middle rays of the caudal fin in moderate to large-sized specimens, the lack of a reticulate pattern on the body in adults, and the possession of 9 branched dorsal-fin rays.

Among the curimatids known from the Río Paraguay basin Cyphocharax gillii can be most easily confused with C. spilotus which has a broad distribution in that system. The two species can, however, be distinguished by the 9 branched dorsal fin rays of C. gillii contrary to the 10 to 12 branched fin rays in C. spilotus. Cyphocharax gillii has 29 to 31 vertebrae with 91% of the 107 radiographed specimens having 29 or 30 vertebrae. Cyphocharax spilotus has 30 to 32 vertebrae, a range partially overlapping that of C. gillii; however, in C. spilotus 87% of the 72 radiographed specimens have 31 or 32 vertebrae. Finally, the spot of dark pigmentation on the midlateral surface of the caudal peduncle is rounded in C. gillii and typically horizontally elongate in C. spilotus, although somewhat diffuse in the largest examined specimens of the latter species.

DESCRIPTION.—Body moderately elongate, somewhat compressed laterally at all sizes. Dorsal profile of head convex from tip of upper lip to vertical line through anterior nostril, straight or very slightly convex from that line to tip of supraoccipital spine. Dorsal profile of body smoothly curved from tip of supraoccipital spine to origin of dorsal fin; nearly straight and posteroventrally slanted at base of dorsal fin, gently convex from base of last dorsal-fin ray to caudal peduncle. Dorsal surface of body with indistinct median keel anterior to dorsal fin, smoothly rounded transversely posterior to fin. Ventral profile of body gently curved from tip of lower jaw to caudal peduncle. Prepelvic region somewhat flattened transversely, without discrete median series of scales. Obtuse median keel posterior to pelvic-fin origin. Secondary obtuse keel on each side of postpelvic portion of body one scale dorsal of ventral midline.

Greatest body depth at origin of dorsal fin, depth 0.36–0.45 [0.38]; snout tip to origin of dorsal fin 0.50–0.54 [0.53]; snout tip to origin of anal fin 0.82–0.87 [0.83]; snout tip to origin of pelvic fin 0.53–0.59 [0.57]; snout tip to anus 0.76–0.81 [0.80]; origin of dorsal fin to hypural joint 0.54–0.61 [0.56]. Distal margin of dorsal fin slightly convex; last unbranched and first branched rays two and three-quarters to three times length of ultimate ray. Pectoral fin pointed in profile; length of pectoral fin 0.20–0.23, extending about two-thirds distance to vertical line through origin of pelvic fin. Margin of pelvic fin pointed; length of pelvic fin 0.23–0.26, reaching about two-thirds distance to origin of anal fin. Caudal fin forked, lobes pointed. Adipose fin well developed. Anal fin emarginate. Least depth of caudal peduncle 0.13–0.15.

Head profile pointed overall, rounded anteriorly; head length 0.28–0.33 [0.30]; upper jaw slightly longer than lower, mouth slightly subterminal; snout length 0.27–0.32 [0.31]; nostrils of each side very close, anterior circular, posterior crescent- shaped with aperture closed by thin flap of skin separating nares; orbital diameter 0.30–0.37 [0.32]; adipose eyelid present but only moderately developed, with nearly rotund opening over center of eye; length of postorbital portion of head 0.36–0.42 [0.39]; gape width 0.21–0.27 [0.24]; interorbital width 0.42–0.48 [0.43].

Pored lateral-line scales from supracleithrum to hypural joint 28 to 33 [30]; all scales of lateral line pored in specimens above 27 mm SL, smaller specimens with pores developed to varying degrees along lateral line, canals in pored lateral-line scales straight; 2 to 4 series of pored scales extending beyond hypural joint onto caudal-fin base; 5 to 6 [5] scales in transverse series from origin of dorsal fin to lateral line; 4 or 5 [4] scales in transverse series from lateral line to origin of anal fin.

Dorsal-fin rays ii,9 or iii,9 (iii,9 rare; when three unbranched rays present, first very short) [ii,9]; anal-fin rays ii,7 or iii,7 (iii,7 rare; when three unbranched rays present, first very short) [ii,7]; pectoral-fin rays 13 to 15; pelvic-fin rays i,8 [i,8].

Total vertebrae 29 (5), 30 (92), 31 (10).

COLOR IN LIFE.—Photographs in Sazima (1988) show that the fish in life is silvery with a dark spot obvious on the midlateral surface of caudal peduncle.

COLOR IN ALCOHOL.—Specimens retaining guanine on scales silvery overall. Overall coloration of specimens lacking guanine on scales tan, darker on snout, dorsal portions of head and dorsal surface of body. Deep-lying dark stripe extending along lateral surface of body from supracleithrum to caudal peduncle; expanded on lateral surface of peduncle into a triangular spot. Streak more obvious and discrete in specimens under 35 mm SL, less noticeable anteriorly and more diffuse posteriorly in larger specimens. Spot of dark pigmentation about size of orbit formed by large series of small chromatophores overlying deeper situated spot on caudal peduncle. Spot of surface pigmentation rotund, or slightly triangular anteriorly. Margin of spot not distinct, with less dense field of chromatophores extending dorsal and ventral of central spot to dorsal and ventral margins of caudal peduncle. Dorsal, caudal, and anal fins somewhat dusky, more so in larger specimens; pectoral and pelvic fins hyaline.


DISTRIBUTION.—Rio Paraguay system in Brazil and Paraguay (Figure 80).

KARYOTYPE.—Venere and Galetti (1989:19–21) reported 2n = 54 chromosomes in the species.

ECOLOGY.—Sazima (1986:55) reported that Cyphocharax gillii (cited as Curimata spilura) swims near the bottom when feeding, and scoops up and ingests portions of the substrate containing food items including diatoms, desmids, and epiphytic filamentous algae. In a later paper Sazima (1988:191) noted that some members of the species defended territories that included submerged grassy plants with algal cover. Such territories were defended by chases, nips, strikes, and mouth fighting. Individuals protecting territories would attack their own image in mirrors. Other individuals of Cyphocharax gillii in the same region did not protect territories, but rather formed schools of up to 30 individuals. Sazima and Pellegrini Caramaschi (1989:326) noted that contrary to some other curimatids, the species “visually inspects the substrate, takes successive mouthfuls from the substrate and rarely spits out part of the sediment,” with the predominant dietary item being filamentous algae. Géry et al. (1987:418) reported that C. gillii typically inhabits small streams or regions of weak currents in adjoining swampy areas. In rivers it is usually captured along the banks.

DISTRIBUTION.—Central and western portions of the Rio Amazonas basin (Figure 92).

GEOGRAPHIC VARIATION.—The population samples of this species from the upper portions of the Rio Madeira system in Peru and Bolivia differ slightly from available samples of the species from the central portions of the Amazon basin and from those originating to the north along the Andean piedmont. The average relative length of the postorbital portion of the head in the Rio Madeira populations (0.38–0.44 of HL) tends to be proportionally somewhat less than for the population samples from the other portions of the species range (0.40–0.46 of HL), albeit with pronounced overlap in ranges. The Rio Madeira samples also tend to have darker pigmentation than do many specimens from Peru and central portions of the Amazon basin. Such dark pigmentation does occur in some population samples from those latter areas, and may simply reflect different water types from which the samples were taken. These differences consequently do not serve to discriminate the populations as recognizable species.

MATERIAL EXAMINED.—314 specimens (90, 23.3–89.9).

BRAZIL. Amazonas: Iça (= Rio Içá (tributary of Rio Solimões) near Brazilian-Colombian border), MCZ 92961, 1 (70.7, lectotype of Curimatus spiluropsis; formerly MCZ 20218, in part); MCZ 20216, 20218, 27408, 5 (3, 47.6–approx. 55; type and non-type lots intermingled, paralectotypes of Curimatus spiluropsis); USNM 120403, 2 (51.3–53.8, paralectotypes of Curimatus spiluropsis; out of intermingled lots MCZ 20216, 20218, 27408). Lake Hyanuary (= Paraná do Janauari), MCZ 20268, 25 (5, 48.9–67.5). Paraná da Ilha de Marchantaria, USNM 309297, 1 (48.0). Ilha de Marchantaria, Camaleao, USNM 309292, 2. São José, Lago do Castanho, Janauacá, USNM 229183, 2 (61.6–73.0); USNM 311130, 1 (49.3). Lago Janauari, USNM 309296, 1 (63.4); USNM 309294, 2 (48.4–49.5; 1 specimen cleared and counterstained for cartilage and bone); USNM 311132, 42 (10, 39.7–46.8). Lago Janauari, near its outflow channel, USNM 229182, 4 (43.3–63.4). Lago Terra Preta, Janauari, USNM 311124, 2 (36.4–41.3). Acre: Río Tarauacá, Tarauacá, Lago da Esperanca, USNM 268012, 15 (9, 59.2–80.2). Mato Grosso: Rio Guaporé basin, Rio Alegre, approx. 3 km from Vila Bela da Santíssima Trindade, MZUSP 37474, 1. Rio Guaporé system, Vila Bela da Santíssima Trindade, MZUSP 37767, 23. Rondônia: Rio Madeira, Porto Velho, MZUSP 20675, 9.

PERU. Loreto: Río Marañon, Nauta, ANSP 21424, 1 (holotype of Curimatus stigmaturus;, specimen in poor condition, not possible to determine SL); ANSP 21425–21427, 3 (paratypes of Curimatus stigmaturus; specimens in poor condition, not possible to determine SL). Río Ucayali system, isolated pool at left bank of Quebrada Carahuayate, at km 20 on road from Jenaro Herrera to Colonia Angamos, NRM 26542, 32 (10, 52.0–75.0). Río Corrientes system, Teniente Lopez, pools on right bank, opposite OXY Camp, NRM 26576, 2 (46.8–65.8). Río Nanay system, Quebrada Correntillo, 20 km from Iquitos on road from Iquitos to Puerto Aimendra, NRM 26544, 1 (61.3). Yaguas Yacu, CAS-SU 60541, 1; USNM 311123, 10. Río Ucayali, Contamana, ANSP 68670, 1 (58.7, holotype of Curimatoides ucayalensis). Ucayali: Pucallpa, Cashibococha, MZUSP 26305, 6. Río Ucayali system, Masisea, Lobococha, USNM 311100, 5 (53.1–76.9). Madre de Dios: Reserva Natural de Tambopata (approx. 12°50′30″S, 69°17′30″W), USNM 263973, 2 (46.5–65.5). Reserva Natural de Tambopata, Laguna Chica (approx. 12°50′30″S, 69°17′30″W), USNM 263980, 8 (7, 39.4–89.9). Reserva Natural de Tambopata, Laguna Cocococha, approx. 5.1 km E of Explorer's Inn (approx. 12°49′S, 69°17′30″W), USNM 263974, 4. Reserva Natural de Tambopata, stream entering Río Tambopata from S bank, approx. 500 m downstream of Explorer's Inn boat-landing (approx. 12°49′35″S, 69°17′30″W), USNM 263976, 1. Río Tambopata system, quebrada and roadside pools at km 14 along road from Puerto Maldonado to Cuzco, NRM 26543, 1 (56.0).

ECUADOR. Napo: Río Chespirito, below the bridge on the road to Tarapoa, USNM 311318, 2 (72.5–86.0). Laguna Añangococha (0°32′S, 76°26.7′W), USNM 311324, 2 (66.0–69.7).

BOLIVIA. Beni: Río Beni, Cachuela Esperanza, CAS 63049, 1 (23.3, lectotype of Curimata (Hemicurimata) esperanzae; formerly IU 17281, in part); CAS 63050, 5 (paralectotypes of Curimata (Hemicurimata) esperanzae; formerly IU 17281, in part). Borrow-pit by road approx. 1.5 km W of crossing of Río Matos, 45 airkm E of San Borja (approx. 14°56′S, 66°17′W), USNM 305335, 75 (10, 39.2–72.5). Río Mamore, Laguna Santa Rosa, USNM 278565, 3. Río Itenez (= Guaporé), at confluence of Río Itenez and Río Machupo, USNM 278560, 5 (3, 39.3–52.5). Provincia Ballivia, marsh channel draining Lago Normandia, approx. 1 km N of lake, 40 airkm E of San Borja (approx. 14°55′S, 66°18′W), USNM 305404, 5.