Comprehensive Description
(
الإنجليزية
)
المقدمة من Smithsonian Contributions to Zoology
Potamorhina pristigaster (Steindachner)
Curimatus (Anodus) pristigaster Steindachner, 1876:73, pl. 68 [type-locality: Brazil: mouth of Rio Negro, Tefé].
Potamorhina pristigaster.—Cope, 1878:685 [Peruvian Amazon].—Eigenmann and Eigenmann, 1889:411 [Brazil: Teffe (= Tefé), Lake Hyanuary (= Januari)]; 1891:46 [reference].—Fowler, 1906:306 [Peruvian Amazon]; 1942:210 [reference]; 1945:119 [compilation]; 1950:299, fig. 377 [bibliography]; 1975:377 [reference].—Eigenmann, 1910:420 [reference].—Eigenmann and Allen, 1942:289 [Peru: Iquitos].—Fernandez-Yepez, 1948:32, fig. 12 [reference].—Marlier, 1968:25, 38 [Brazil: Lac Redondo; diet].—Smith, 1981:140 [Brazil: Itacoatiara; market fish].
Curimata (Potamorhina) pristigaster.—Géry, 1977:230 [Amazon, Rio Negro].
Potamorrhina pristigaster.—Braga and Azpelicueta, 1983: 148 [in key].
DIAGNOSIS.—A moderate-sized Potamorhina species reaching 214 mm SL. Potamorhina pristigaster is easily distinguished from the other members of the genus by its apomorphously transversely flattened or slightly concave prepelvic region, which is delimited laterally by distinct longitudinally aligned keels, and by its highly serrate postpelvic median keel. Neither character occurs in any other Potamorhina species.
DESCRIPTION.—Body moderately elongate, compressed. Dorsal profile of head concave, more so in juveniles. Dorsal profile of body distinctly convex to origin of rayed dorsal fin; straight and distinctly posterodorsally slanted at base of rayed dorsal fin, straight or slightly convex from insertion of last dorsal-fin ray to caudal peduncle. Dorsal surface of body with a median keel anterior to rayed dorsal fin, rounded posterior to fin. Ventral profile of body smoothly curved from tip of lower jaw to lower margin of caudal peduncle. Prepelvic region transversely flattened or slightly concave, with distinct longitudinal lateral keels that extend from behind vertical through insertion of pectoral fin to point of insertion of lateralmost pelvic-fin ray (see Steindachner, 1876, pl. 68). A prominent median keel between pelvic fin insertion and anus; keel margined by a series of distinctly serrate scales.
Greatest body depth at origin of rayed dorsal fin, depth 0.40–0.50 [0.45]; snout tip to origin of rayed dorsal fin 0.45–0.54 [0.53]; snout tip to origin of anal fin 0.76–0.81 [0.78]; snout tip to insertion of pelvic fin 0.50–0.58 [0.51]; snout tip to anus 0.72–0.80 [0.75]; origin of rayed dorsal fin to hypural joint 0.56–0.61 [0.60]. Rayed dorsal fin pointed, posterior margin concave, particularly in larger individuals; second unbranched and anterior branched rays filamentous, length of first branched ray 3.5–4.0 times length of ultimate dorsal-fin ray, reaches to adipose dorsal fin in some specimens. Pectoral fin pointed, length of pectoral fin 0.19–0.26 [0.20]; fin reaches distinctly beyond vertical through pectoral fin insertion in all but largest specimens examined, in which it extends only to vertical through fin insertion. Pelvic fin pointed, length of pelvic fin 0.18–0.24 [0.21]; fin reaches three-fifths to three-quarters distance to origin of anal fin in adults, slightly more posteriorly in smaller specimens. Anal fin emarginate, anteriormost rays twice length of ultimate ray. Adipose dorsal fin well developed. Caudal peduncle depth 0.11–0.12 [0.12].
Head distinctly pointed in profile, head length 0.31–0.38 [0.32]; jaws equal, mouth terminal; snout length 0.25–0.30 [0.27], nostrils of each side close together, anterior opening circular, posterior cresent-shaped; orbital diameter 0.22–0.28 [0.26]; adipose eyelid present, most highly developed anteriorly, particularly in larger specimens, with a vertically ovoid opening over middle of eye; postorbital portion of head elongate, length 0.49–0.54 [0.50]; gape width 0.28–0.34 [0.30]; interorbital width 0.40–0.47 [0.42].
Pored lateral line scales from supraleithrum to hypural joint 86 to 106 [102]; lateral line canals straight or diverge slightly dorsally and ventrally. Seven to 12 series of scales extend beyond hypural joint onto caudal fin base; 26 to 32 [29] scales in a transverse series from origin of rayed dorsal fin to lateral line, 22 to 28 [24] scales in a transverse series from lateral line to origin of anal fin. All scales distinctly ctenoid, those that form border of postpelvic median ridge flexed over ridge and with strongly developed, posteroventrally oriented ctenii.
Rayed dorsal-fin rays ii,9–10 [ii,9]; anal-fin rays ii,11–13 or iii,11–13 [iii,12]; pectoral-fin rays 14 to 17 [16]; pelvic-fin rays i,8–9 [i,8].
Total vertebrae 33 (15), 34 (4).
Color in Alcohol: Overall coloration silvery-yellow to silvery-brown, head and body with pigmentation more intense dorsally. Dark coloration of dorsal portion of head extends posteroventrally onto dorsal half of opercle. A distinct, small, round spot located midlaterally on posterior portion of caudal peduncle. All fins with scattered small chromatophores that outline fin rays.
DISTRIBUTION.—Rio Amazonas drainage basin (Figure 9).
MATERIAL EXAMINED.—80 specimens (53, 37.0–219.7).
BRAZIL. Pará: No specific locality, AMNH 12708, 1 (137.8). Rio Maycuru, NRM LAK 7129, 1 (148.2). Rio Tapajós at Santarem, MZUSP 3714, 1 (165.4). Amazonas: Tefé, NMW 66920, 1 (210.0; lectotype of Curimatus (Anodus) pristigaster); NMW 66921, 1 (202.0; paralectotype of Curimatus (Anodus) pristigaster); NMW 58205, 1 (206.0; paralectotype of Curimatus (Anodus) pristigaster); MCZ 20255, 4 (170.0–214.4); MNHN 09–122, 1. Rio Tefé, Supiâ-pucu, USNM 242146, 2. Rio Tefé, Mucura, USNM 242145, 2. Tabatinga (Sapurara), MNHN 09-168, 1. Vicinity of Manaus, USNM 228693, 3 (66.5–108.5; 1 cleared and counterstained for cartilage and bone). Mouth of Rio Negro, NMW 67046, 1 (161.3, paralectotype of Curimatus (Anodus) pristigaster). Manacapuru, BMNH 1925.10.28.60, 1 (196.0). Lake Hyanuary (= Januari), MCZ 19033, 12 (8, 135.0–201.5); MZUSP 6863, 5 (3, 107.1–126.8). Lago do Miguel, 20 km below Itacoatiara, MZUSP 13487–88, 2 (182.7–219.7). Igarape Jaraqui, MZUSP 6182, 2 (185.9–215.2). Lago Janauacá, MZUSP 21560, 7 (193.4–216.4). Mouth of Rio Purus, MZUSP 5948, 6 (5, 83.0–207.1). Lago Jacare, MZUSP 6454, 10. Maués, Igarape of Rio Marau, MZUSP 7322, 2. Roraima: Rio Branco, Xeriuini, USNM 242147, 1. Rio Branco, Marara, USNM 2573661, 1.
PERU. Peruvian Amazon, ANSP 21520–22, 3 (120.5–178.0). Loreto: Río Ampiyacu, USNM 228683, 1 (36.8); SU 64310, 1. Pevas, CAS-SU 36609, 1 (93.5). Iquitos, USNM 228700, 1 (148.0). Iquitos, Cocha Zegarra off Río Itaya, MZUSP 15234, 1 (178.3). Iquitos, Cocha Aguajal, MZUSP 15233, 1 (158.3). Ucayali: Pucallpa, Cashibococha, MZUSP uncat., 2 (106.0–119.5).
- الاقتباس الببليوغرافي
- Vari, Richard P. 1984. "Systematics of the Neotropical characiform genus Potamorhina (Pisces, Characiformes)." Smithsonian Contributions to Zoology. 1-36. https://doi.org/10.5479/si.00810282.400
这是一篇關於魚類的小作品。你可以通过编辑或修订扩充其内容。 