Comprehensive Description
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الإنجليزية
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المقدمة من Smithsonian Contributions to Zoology
Steindachnerina amazonica (Steindachner, 1911)
Curimatus elegans var. amazonica Steindachner, 1911:330 [type-locality: Brazil: Rio Tocantins].—Vari, 1989a, tables 2.3 [assignment to Steindachnerina].
Curimatus elegans amazonicus.—Fernández-Yépez, 1948:73 [reference].
Curimata elegans amazonica.—Fowler, 1950:282 [literature compilation].
Pseudocurimata elegans amazonicus.— Fowler, 1975:372 [reference].
DIAGNOSIS.—The multiple series of tabulate fleshy processes on the roof of the oral cavity, absence of a wide, flattened, prepelvic region of the body, presence of a dark spot on the basal portions of the middle rays of the dorsal fin, presence of a dark midlateral stripe on the body, and the possession of 36 to 41 lateral-line scales to the hypural joint, in combination, discriminate Steindachnerina amazonica from its congeners.
DESCRIPTION.—Body moderately elongate, somewhat compressed. Dorsal profile of head convex anteriorly, straight from vertical line through posterior nostril posteriorly to rear of head. Dorsal profile of body slightly convex from rear of head to origin of dorsal fin; straight and posteroventrally slanted at base of dorsal fin, straight from base of last dorsal-fin ray to caudal peduncle. Dorsal surface of body transversely rounded anteriorly, 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 obtusely flattened transversely proximate to pelvic-fin origin. Postpelvic region irregularly rounded.
Greatest depth of body 0.32–0.35 [0.32]; snout tip to origin of dorsal fin 0.47–0.53 [0.47]; snout tip to origin of anal fin 0.83–0.88 [0.84]; snout tip to insertion of pelvic fin 0.52–0.58 [0.52]; snout tip to anus 0.78–0.83 [0.78]; origin of dorsal fin to hypural joint 0.53–0.58 [0.56]. Dorsal-fin margin emarginate, more so in larger individuals in which anterior rays are somewhat lengthened; anteriormost rays two to two and three-quarters times length of ultimate ray. Pectoral-fin margin pointed; length of pectoral fin 0.18–0.23 [0.18], extends about two-thirds distance to vertical line through insertion of pelvic fin. Pelvic-fin margin pointed, length of pelvic fin 0.19–0.22 [0.22], reaches two-thirds to three-quarters distance to origin of anal fin. Caudal fin forked. Adipose fin well developed. Anal fin emarginate, anteriormost branched rays about two and one-half times length of ultimate ray. Caudal peduncle depth 0.12–0.14 [0.12].
Head obliquely pointed in profile, head length 0.26–0.30 [0.28]; upper jaw distinctly longer, mouth inferior; portion of buccopharyngeal complex on roof of oral cavity in adults consisting of multiple tabulate fleshy bodies; snout length 0.29–0.31 [0.30]; nostrils very close, anterior circular, posterior crescent-shaped, with aperture closed by thin flap of skin separating nares; orbital diameter 0.28–0.33 [0.28]; adipose eyelid present, more developed anteriorly, with broad vertically ovoid opening over center of eye; length of postorbital portion of head 0.42–0.46 [0.45]; gape width 0.23–0.26 [0.26]; interorbital width 0.38–0.44 [0.38].
Pored lateral-line scales to hypural joint 36 to 41 [40]; all scales of lateral line pored, canals in lateral-line scales straight; 3 to 5 series of scales extend beyond hypural joint onto caudal-fin base; 5½ to 6½ [6½] scales in transverse series from origin of dorsal fin to lateral line; 4½ to 5½ [5½] scales in transverse series from lateral line to origin of anal fin.
Dorsal-fin rays ii,9 or ii,10, 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) [iii,7]; pectoral-fin rays 13 or 14 [13]; pelvic-fin rays i,8 [i,8].
Total vertebrae 31 (1), 32 (7), 33 (2) [33].
COLOR IN ALCOHOL.—Overall coloration of specimens retaining guanine on scales silvery, darker on dorsal portions of head and body. An indistinct dark band extends along lateral line; band more prominent and wider posteriorly (Figure 58). Ground coloration of specimens lacking guanine on scales tan, darker dorsally (Figure 59). Dorsal midline with narrow stripe of dark pigmentation extending from rear of head to dorsal fin, and from rear of dorsal fin to adipose fin. Lateral line with series of spots of dark pigmentation along scales; spots merge posteriorly into midlateral longitudinal stripe; stripe wider posteriorly. Stripe terminates on caudal peduncle in smaller individuals, extends onto basal portion of middle rays of caudal fin in some larger specimens. Dorsal fin with patch of dark pigmentation on basal portion of membranes between branched rays three and five. Patch most intense in smaller individuals (Figure 59), less apparent in larger specimens examined (Figure 58). Difference possibly a consequence of differing lengths of time various specimens have been in preservative, but paralleling ontogenetic shift found in other species of Steindachnerina. Remainder of dorsal fin together with anal and caudal fins ranging from hyaline to dusky in various specimens. Some larger specimens with stripe of dark pigmentation on middle rays of caudal fin, stripe more prominent anteriorly. Paired fins hyaline.
DISTRIBUTION.—Rio Tocantins basin of eastern Brazil (Figure 60).
COMPARISONS.—Steindachnerina amazonica is the only member of the genus known from the Rio Tocantins basin. The southern tributaries of that system approximate the northern portions of upper Rio Paraná that has an endemic Steindachnerina species, S. insculpta, in its fauna. The upper reaches of the eastern tributaries of the Tocantins, in turn, lie close to the known range of S. notonota. Steindachnerina amazonica differs from both of those species in the possession of a distinct spot of dark pigmentation on the basal portions of the middle rays of the dorsal fin, whereas such pigmentation is absent in the other two forms.
DISTRIBUTION.—Rivers of northwestern tip of Guyana, Río Orinoco basin, foothill rivers of western portion of Amazon basin in Colombia, Brazil, Ecuador, Peru, and northern Bolivia (Figure 60). The limited ichthyological collecting that has been carried out to the south of the known range of Steindachnerina guentheri in Bolivia makes it difficult to determine even the general limits of the distribution of the species in that section of the continent. We can be somewhat more certain of the limits of the range of the species in northeastern South America. Although the freshwater fish fauna of Guyana has not been exhaustively collected, the relatively inclusive collecting efforts in the other river systems of Guyana, most notably the Essequibo system, have not revealed specimens of Steindachnerina guentheri, or indeed of any member of the genus. The known distribution of S. guentheri in Guyana is limited to a few small rivers whose mouths are associated with the delta of the Rio Orinoco. These drainages are, in contrast, quite separate from the major independent river systems in Guyana lying further to the south.
MATERIAL EXAMINED.—355 specimens (142, 29.5–111.3).
GUYANA. Essequibo: Issororo Rubber Plantation, FMNH 53647.1 (74.0, holotype of Curimatus issororoënsis, formerly CM 2119); FMNH 53651, 1 (69.1, paratype of Curimatus issororoënsis, formerly CM 2120); CAS 60625, 1 (73.5, paratype of Curimatus issororoënsis, formerly IU 12301). Morawhanna, FMNH 53650, 1 (61.9, holotype of Curimatus morawhannae, formerly CM 2122); FMNH 53649, 10 (30.3– 61.7, paratypes of Curimatus morawhannae, formerly CM 2121 in part, see “Remarks”); SU-CAS 21901, 2 (32.5–35.9, paratypes of Curimatus morawhannae, formerly IU 12303); BMNH 1911.10.31:479, 1 (42.6, paratype of Curimatus morawhannae, formerly IU 12303). Mora Passage, USNM 66142.2 (paratypes of Curimatus morawhannae); CAS 44222, 1 (32.1, paratype of Curimatus morawhannae, formerly IU 12302); BMNH 1917.11.2:7, 1 (43.9, paratype of Curimatus morawhannae). Middle Barama River, USNM 298094, 2 (1, 62.3). Watapoa, BMNH 1972.7.27:397-398, 2 (58.3–62.5). Aruau River, AMNH 14552, 2.
VENEZUELA. Territorio Federal Delta Amacuro: Small carlo at mouth of Caño Fiscal (~08°32′N, 61°02′W), USNM 235494, 25 (15, 40.8–55.4). Caño Paloma system (~08°28′N, 61°25′36″W), USNM 235504, 32 (10, 30.6–40.7). Caño Aragua system (~08°38′N 61°43′W), USNM 235512, 9. “Delta del Orinoco,” MBUCV uncat., 4 (37.3–53.4; formerly MAC 67360). Monagas: Río Caripe, Chorrereas near Caripito, MBUCV V-12402, 1 (68.3). Río Orinoco, Barrancas, Laguna El Guatero, USNM 235490, 13. Río Morichal Largo, El Silencio, below bridge from Maturin to Tremblador, MBUCV V-15259, 15. Río Morichal Largo, El Salto, MBUCV V-15260, 2. Amoatequi: Río Uruspia, Río Tigre basin, near San Tomé, USNM 298033, 6 (60.3–81.7). Bolivar: Laguna on south side of Isla Isabella (~08°18′43″N, 65°56′52″W), USNM 235478, 6. Apure: Caño Léon, 14 km S of El Piñal (San Camilo), MBUCV uncat, 11 (3, 80.0–87.9, formerly MAC 23–15). San Fernando de Apure, USNM 258091, 12.
COLOMBIA. Meta: Villavicencio, Quebrada Cramalote, FMNH 55143, 1 (93.3, holotype of Curimatus metae, formerly CM 3844); CAS 60585, 2 (50.9–89.8, paratypes of Curimatus metae, formerly IU 15023). Barrigón, USNM 83632, 9 (55.5–77.6, formerly IU 15022, in part); CAS 60586, 3 (81.5–111.3, formerly IU 15022, in part); USNM 298031, 6 (52.3–88.8, formerly IU 15022, in part). Río Ocoa, approximately 15 km E of Villavicencio, NRM SIL/1988014.3141, 14. Caño Union, tributary to Río Ocoa, where crossed by Villavicencio to Acacias Road, NRM SIL/1988013.319, 3. Laguna Santa Clara, Río Ocoa system, 5 km S of Villavicencio, NRM SIL/1988026.3134, 4. Río Upia, Guaricaramo, USNM 94284, 1 (82.0).
ECUADOR. Napo: Río Payamino at Puerto Coca, USNM 298157, 1 (49.0). Pastaza: Río Villano, Villano, USNM 164051, 2 (62.2–85.6).
PERU. Loreto: Yurimaguas, CAS 63052, 1 (64.7, lectotype of Curimata robustula, formerly IU 15830, in part); CAS 63053, 7 (49.0–67.4, paralectotypes of Curimata robustula, formerly IU 15830, in part). Río Ucayali system, Quebrada Carahuayate, km 20 along road from Jenaro Herrera to Colonia Angamos, NRM SOK/ 1983347.3733, 1 (80.7). Río Yavari system, Colonia Angamos, NRM SOK/1984305.4043, 1 (37.9). Río Corrientes system. Teniente Lopez, NRM SOK/ 1986312.4689, 45. Amazonas: Río Kayamasa, 41 km upstream from Caterpiza, LACM 41856–3, 2 (1, 89.5). Ucayali: Quebrada Pecheria, IVITA station, 60 km from Pucallpa along Pucallpa to Huanuco road, USNM 261475, 1 (88.0). IVITA station, AMNH 35684, 1 (73.0); AMNH uncat, 1. Río Neshuyo, km 60 on Pucallpa to Huanuco Road, USNM 261409, 3 (63.1–78.6); USNM 298034, 3 (1, 77.4); USNM 298038, 4; USNM 298300, 5. Río Ucayali basin, stream on Pucallpa to Tournavista road, GC, 2 (1, 54.5). Huanuco: Quebrada Ayamira, Río Pachitea system, BMNH 1969.11.18:1, 1 (63.2); USNM 220347, 1 (29.5); USNM 204599, 1 (64.4). Río Pachitea system, pool l km upstream of Tournavista, NRM SOK/3460, 3 (2, 57.4–64.7). Río Yamushimas, Rfo Pachitea system, USNM 298035, 4 (48.4–78.4). Cajamarca: Río Marañon basin, tributary to Río Tabaconas, 52 km N of Jaen, ROM uncat, 2; ROM uncat., 5. San Martin: Moyabamba, Río Yuracyacu system, USNM 298156, 2; USNM 298036, 6. Madre de Dios: Río Tambopata system, Quebrada San Roque at km 11 on Puerto Maldonado to Cuzco road, NRM SOK/1983325.3736, 1 (75.7). Stream entering Río Tambopata 500 m downstream of Inn on Tambopata Reserve (~12°49′35″S, 69°17′30″W), USNM 263977, 5 (4, 65.0– 86.9). Stream in Reserva Natural de Tambopata (~12°50′30″S, 69°17′30″W), USNM 263978, 4 (3, 80.5–89.7). Parque Nacional Manú, Pakitza, USNM 295254, 2. Río Madre de Dios, 10 km downstream of junction of Río Tambopata and Río Madre de Dios, USNM 263979, 4.
BRAZIL. Amazonas: Tabatinga, MCZ 20245, 1 (57.1, holotype of Curimatus güntheri).
BOLIVIA. La Paz: Huachi, junction of Río Bopi and Río Cochabamba, UMMZ 66511, 11 (48.5–73.4, formerly IU 17137, in part); USNM 298160, 4 (64.0–72.5, formerly IU 17137, in part). Cochabamba: Río Chapare, between Todos Santos and mouth, MZUSP 278221, 4 (2, 45.4–47.3). Río Chapare, above Todos Santos, GC, 1 (66.1). Río Chapare, Todos Santos, ANSP 68911–14, 5. Streams in region of Todos Santos, GC, 1 (51.3). Río Chapare, GC, 1 (75.7).
- الاقتباس الببليوغرافي
- Vari, Richard P. 1991. "Systematics of the neotropical characiform genus Steindachnerina Fowler (Pisces: Ostariophysi)." Smithsonian Contributions to Zoology. 1-118. https://doi.org/10.5479/si.00810282.507
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