Comprehensive Description
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добавил Smithsonian Contributions to Zoology
Psectrogaster essequibensis (Günther)
Curimatus ciliatus.—Kner, 1859a:143 [in part; Río Guaporé].—Eigenmann. 1912:268 [Curimatus essequibensis Günther, 1864, placed into synonymy of Anodus ciliatus Müller and Troschel, 1845; references in part, only C. essequibensis citations; all listed specimens, British Guiana (= Guyana): Rupununi, Rockstone, Crab Falls, Warraputa, Konawaruk].
Curimatus essequibensis Günther, 1864:291 [type locality: Essequibo].—Eigenmann 1910:422 [reference]; 1912:268 [placed as a synonym of Anodus ciliatus Müller and Troschel, 1845].—Fernández-Yépez, 1948:73 [as probable synonym of Anodus (= Hamatichthys) ciliatus].—Vari, 1989, tables 2, 3 [phylogenetic relationships].
Psectrogaster ciliata.—Eigenmann and Eigenmann, 1889b:413 [references in part, Kner, 1859a citation].
Curimata essequibensis.—Géry, 1977:230 [as possible synonym of Curimata ciliata].
Psectrogaster essequibensis.—Ortega and Vari, 1986:11 [Peru, Amazon basin; common name].
DIAGNOSIS.—The possession of a transversely flattened prepelvic region with enlarged scales distinguishes Psectrogaster essequibensis from all other members of the genus with the exception of P. falcata. Psectrogaster essequibensis can be separated from that species in having 39 to 49 lateral line scales to the hypural joint in contrast to 54 to 62 in P. falcata. Similarly the presence of 7 to 10 scales below the lateral line to the origin of the anal fin in P. essequibensis separates that species from P. falcata, which has 10 to 13 scales in that series.
DESCRIPTION.—Body moderately elongate, somewhat compressed, slightly convex from rear of head to origin of rayed dorsal fin, convexity more pronounced in larger specimens; profile of body straight and posteroventrally slanted at base of rayed dorsal fin, gently convex from base of last dorsal-fin ray to caudal peduncle. Dorsal surface of body with an indistinct median keel anterior to rayed dorsal fin, smoothly rounded transversely posterior to fin. Ventral profile of body gently curved from tip of lower jaw to caudal peduncle. Prepelvic region flattened, bordered laterally by distinct, nearly right, angle in body wall; angle extends approximately from vertical through origin of pectoral fin to origin of pelvic fin. Flattened prepelvic region with distinct median series of enlarged scales, scales immediately lateral to median series similarly enlarged and conform in shape to lateral angles of prepelvic body wall. Distinct median keel extends from origin of pelvic fin to anus. Secondary obtuse flexure in postpelvic body wall located approximately 2 scale rows dorsal of ventral midline on each side of body.
Greatest body depth at origin of rayed dorsal fin, depth 0.39–0.49 [0.44]; snout tip to origin of rayed dorsal fin 0.48–0.54 [0.51]; snout tip to origin of anal fin 0.79–0.85 [0.82]; snout tip to origin of pelvic fin 0.55–0.61 [0.56]; snout tip to anus 0.76–0.83 [0.77]; origin of rayed dorsal fin to hypural joint 0.54–0.60 [0.58]. Rayed dorsal fin pointed, first branched ray longest, anteriormost rays 2.5–3.5 times length of ultimate ray. Pectoral fin pointed; length of pectoral fin 0.18–0.22 [0.19], extends two-thirds distance to vertical through origin of pelvic fin. Pelvic fin pointed, length of pelvic fin 0.18–0.23, reaches three-quarters of distance to origin of anal fin. Caudal fin forked. Adipose fin well developed. Anal fin emarginate, anterior branched rays over twice length of ultimate ray. Caudal peduncle depth 0.11–0.13 [0.12].
Head profile distinctly pointed, head length 0.31–0.36 [0.33]; jaws equal, mouth terminal; snout length 0.26–0.32 [0.28]; nostrils of each side of head very close, anterior circular, posterior crescent shaped with aperture closed by thin flap of skin that separates nares; orbital diameter 0.26–0.33 [0.28]; adipose eyelid moderately developed, with a vertically ovate opening over center of eye; length of postorbital portion of head 0.41–0.48 [0.46]; gape width 0.28–0.34 [0.33]; interorbital width 0.42–0.49 [0.47].
Pored lateral line scales from supracleithrum to hypural joint 39 to 49 [49]; all scales of lateral line pored, canals in lateral line scales straight; 3 to 7 series of scales extend beyond hypural joint onto caudal fin base; 10 to 15 [13] scales in a transverse series from origin of rayed dorsal fin to lateral line, 7 to 10 [9] scales in a transverse series from the lateral line to origin of anal fin; scales very weakly ctenoid.
Dorsal-fin rays ii,9 [ii,9]; anal-fin rays ii,8–10 [ii,10]; pectoral-fin rays 14 to 16 [15]; pelvic-fin rays i,8–10 [i,9].
Total vertebrae 30 (19).
COLOR IN ALCOHOL.—Specimens that retain guanine on scales golden or silvery golden, overall pigmentation more intense on dorsal portions of head and body. Specimens lacking guanine on scales tan or brownish. No notable pigmentation pattern on head, body or fins. Series of small chromatophores outline fin rays, most notably along distal portions and margins of caudal, anal, and rayed dorsal fins.
DISTRIBUTION.—Essequibo River of Guyana and Rio Amazonas drainage systems (Figure 7).
DISTRIBUTION.—Eastern portions of Rio Amazonas drainage basin (Figure 9).
MATERIAL EXAMINED.—852 specimens (63, 83.0–167.5).
BRAZIL. Pará: Rio Xingu, MCZ 20340, 1 (167.5, lectotype of Curimatus falcatus); MCZ 60393, 2 (138.5–139.5, paralectotypes of Curimatus falcatus, out of MCZ 20340). Rio Xingu, Belo Monte, edge of river, USNM 268043, 29 (10, 122.2–144.0); AMNH 55628, 3 (127.2–137.2); MCZ 61405, 3 (132.8–138.4); MZUSP 32280, 483. Gurupa, MCZ 20189, 1 (135.0, paralectotype of Curimatus falcatus). Rio Jamanxim above Bebal, MZUSP 25474, 1 (126.0). Rio Tapajós, Maloquinha, MZUSP 21399, 1 (126.7). Rio Tapajós, Maloquinha near Itaituba, MZUSP 21899, 5 (99.2–118.3, 1 specimen cleared and counterstained for cartilage and bone). Rio Tapajós, Barreirinha, MZUSP 21409, 1 (125.8). Rio Tapajós, Itaituba, edge of river channel, USNM 268402, 25 (10, 115.3–141.3); USNM 268401, 50 (10, 83.0–101.6); MCZ 61404, 5 (93.8–111.8); AMNH 55627, 5 (91.7–100.1); BMNH 1984.11.8:1–5, 5 (96.2–103.0); MZUSP 32278, 226. Rio Tapajós, So Luís, MZUSP 32279, 6.
Psectrogaster ciliata (Müller and Troschel)
Anodus ciliatus Müller and Troschel, 1845:25, pl. 4, fig. 4 [type locality: British Guiana (= Guyana), Essequibo River]; 1848:633 [reference].—Vari, 1989, tables 2, 3 [phylogenetic relationships],
Curimatus ciliatus.—? Valenciennes (in Cuvier and Valenciennes), 1849:15 [Rio Amazon].—? Castelnau, 1855:58 [Amazon].—Günther, 1864:292 [copied].—Eigenmann, 1912:268 [British Guiana (= Guyana); references in part, not C. essequibensis, C. cyprinoides, or C. rutiloides citations; not Río Paraná or Río Paraguay citations; none of listed specimens.] [Not Perugia, 1891:639.]
Psectrogaster ciliata.—Eigenmann and Eigenmann, 1889b:413 [reference in part, not Kner 1859 citation; not specimens from Coary (= Coari)].—1891:46 [reference].
Psectrogaster ciliatus.—Eigenmann, 1910:420 [reference].—Cockerell, 1914:94 [scale anatomy]. [Not Fowler, 1906:305; Bertoni, 1914:10; 1939:54.]
Curimata ciliata.—Eigenmann and Allen, 1942:295 [references in part, not Fowler, 1940a citation].—Fowler, 1942:207 [references in part, only Anodus ciliatus citation]; 1945:115 [in part, as Fowler, 1942]; 1950:279 [references in part, not C. ciliata or C. ciliatus citations, not figure 339].—Géry, 1977:230 [in key; in part, not synonymy of Curimata essequibensis (Müller and Troschel) or C. isognatha Eigenmann and Eigenmann]. [Not Fowler, 1940a; Ringuelet and Aramburu, 1961:36.]
Hamatichthys ciliatus.—Femández-Yépez, 1948:33, fig. 13 [designation as type species of Hamatichthys].—Ringuelet, Aramburu, and Aramburu, 1967:197 [reference in part, Amazon records].—Ringuelet, 1975:61 [in part, Amazonia].—Fowler, 1975:377 [reference]. [Not Lopez, et al., 1987:20.]
DIAGNOSIS.—Psectrogaster ciliata is a moderate sized member of the genus achieving 130 mm SL. The transversely rounded prepelvic region with moderate sized scales distinguishes P. ciliata from P. essequibensis and P. falcata in which that area is distinctly flattened and bears enlarged scales. Similarly the unpigmented base of the middle rays of the caudal fin, and the possession of a non-serrate margin on the postpelvic median keel in Psectrogaster ciliata separates that species from P. rhomboides, P. amazonica, and P. curviventris, which are characterized by a patch of pigmentation at the base of the middle rays of the caudal fin and a distinctly serrate postpelvic median keel. The absence of either a distinct pigmentation blotch on the lower lobe of the caudal fin, or a series of narrow stripes on the body separates P. ciliata from P. rutiloides, which posesses such a spot, and from P. saguiru, which has faint dark longitudinal striping on the body. The body depth of 0.42–54 of SL in P. ciliata further distinquishes that species from both P. saguiru (0.37–0.42) (Figure 10) and P. rutiloides (0.35–0.42) (Figure 11).
DESCRIPTION.—Body relatively deep, compressed. Dorsal profile of head straight. Dorsal profile of body smoothly convex from rear of head to origin of rayed dorsal fin; slightly convex and posteroventrally slanted at base of rayed dorsal fin, gently convex from base of last dorsal-fin ray to caudal peduncle. Dorsal body surface with an indistinct median keel anterior to rayed dorsal fin, smoothly rounded posterior to fin. Ventral profile of body gently curved from tip of lower jaw to caudal peduncle. Prepelvic region transversely rounded, with very slight indication of lateral angles in body wall immediately anterior to origin of pelvic fins. A distinct median keel posterior to origin of pelvic fin.
Greatest body depth at origin of rayed dorsal fin, depth 0.42–0.54 [0.46]; snout tip to origin of rayed dorsal fin 0.50–0.57 [0.52]; snout tip to origin of anal fin 0.82–0.88 [0.82]; snout tip to origin of pelvic fin 0.54–0.60 [0.55]; snout tip to anus 0.78–0.85 [0.80]; origin of rayed dorsal fin to hypural joint 0.54–0.60 [0.59]. Rayed dorsal fin pointed, anteriormost branched rays 2.5–3.3 times length of ultimate ray. Pectoral fin pointed; length of pectoral fin 0.19–0.24 [0.21], extends three-quarters of distance to vertical through origin of pelvic fin. Pelvic fin pointed, length of pelvic fin 0.18–0.24 [0.19], reaches two-thirds to three-quarters of distance to origin of anal fin. Caudal fin forked. Adipose fin well developed. Anal fin emarginate, anteriormost branched rays approximately twice length of ultimate ray. Caudal peduncle depth 0.12–0.14 [0.12].
. Head profile distinctly pointed, head length 0.30–0.37 [0.32]; jaws equal, mouth terminal; snout length 0.26–0.32 [0.28]; nostrils of each side of head very close, anterior circular, posterior cresent shaped with aperture closed by thin flap of skin that separates nares; orbital diameter 0.26–0.34 [0.28]; adipose eyelid moderately developed, with a ovoid, vertically aligned opening over middle of eye; length of postorbital portion of head 0.41–0.47 [0.46]; gape width 0.28–0.33 [0.31]; interorbital width 0.43–0.48 [0.44].
Pored lateral line scales from supracleithrum to hypural joint 42 to 50 [49]; all scales of lateral line pored, canals in lateral line scales straight; 4 to 8 series of scales extend beyond hypural joint onto caudal fin base; 12 to 16 [14] scales in a transverse series from origin of rayed dorsal fin to lateral line; 8 to 11 [10] scales in a transverse series from the lateral line to origin of anal fin.
Dorsal-fin rays ii,9–10 or iii,9 [ii,9]; anal-fin rays ii,7–8 or iii,7–8 [ii,7]; pectoral-fin rays 13 to 16 [15]; pelvic-fin rays i,8 [i,8].
Total vertebrae 30 (39), 31 (1).
COLOR IN LIFE.—Overall life coloration of specimens from Rio Orinoco (pers. observ.) bright silver, somewhat darker on dorsal portions of head and body. Fins hyaline.
COLOR IN ALCOHOL.—Specimens that retain guanine on scales with an overall golden coloration. Specimens that lack guanine on scales tan or brownish. No pronounced pigmentation pattern on head, body, or fins; overall head and body pigmentation more intense on dorsal portions of head and body. Dark chromatophores more developed along scale margins, particularly dorsal of lateral line. Fin rays outlined by series of dark chromatophores.
DISTRIBUTION.—Essequibo River of Guyana, Río Orinoco drainage basin, Rio Branco, central portion of Rio Amazonas system (Figure 9).
- библиографски навод
- Vari, Richard P. 1991. "Systematics of the neotropical characiform genus Psectrogaster Eigenmann and Eigenmann (Pisces:Characiformes) Richard P. Vari." Smithsonian Contributions to Zoology. 1-43. https://doi.org/10.5479/si.00810282.481
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