Curimata cisandina (Allen 1942)

Curimata cisandina (Allen)

Curimatus macrops.—Eigenmann and Eigenmann, 1889:429 [in part, two non-type specimens from San Paolo (= São Paulo de Olivença)].

Curimatus simulatus.—Eigenmann and Eigenmann, 1889:430 [in part, specimens cited as distinctive from Fonteboa (= Fonte Boa), Brazil].

Psectrogaster cisandinus Allen, in Eigenmann and Allen, 1942:290, pl. 14: fig. 3 [type locality: Peru, Iquitos].—Fowler, 1945:120 [copied]; 1950:301, fig. 362 [reference].

Camposella cisandina.—Fernández-Yépez, 1948:61 [assignment to Camposella].—Fowler, 1975:367 [reference].

Lambepiedra alleni Fernández-Yépez, 1948:62, fig. 33 [type locality: Peru: Lago Cashiboya; designation as type species of Lambepiedra].

Curimata cisandina.—Géry, 1977b:230 [in key].—Ortega and Vari, 1986:11 [Peru; common name].—Vari, 1989, tables 2, 3 [phylogenetic relationships].

DIAGNOSIS.—The combination of 10 to 12 branched anal fin rays, and 45 to 52 pored lateral-line scales to the hypural joint distinguishes Curimata cisandina from all members of this genus with the exception of C. aspera and C. cerasina. Curimata cisandina is separable from those species in having an interorbital width 0.40–0.45 of SL, and most typically 31 vertebrae. In C. aspera and C. cerasina the interorbital widths are 0.46 of HL or greater, and the vertebral count is typically 32 or 33, rarely 31. Curimata cisandina also differs from C. aspera and C. cerasina in numerous internal characters (see “Synapomorphy List and Phylogenetic Reconstruction”).

DESCRIPTION.—Body moderately elongate and compressed. Dorsal profile of head straight or very slightly concave. Dorsal profile of body distinctly convex from rear of head to origin of rayed dorsal fin, more so in larger specimens; straight or somewhat convex and posteroventrally slanted at base of dorsal fin, convex from base of last dorsal-fin ray to caudal peduncle, particularly in larger specimens. Dorsal surface of body with 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, more convex posteriorly. Prepelvic region flattened, margined laterally by distinct, nearly right, angles in body wall; prepelvic region with median series of enlarged scales flanked on each side by series of enlarged scales that conform in shape to lateral angles of body. Distinct median keel posterior to pelvic fin insertion with secondary obtuse angle in body wall about two scales dorsal of ventral midline on each side of postpelvic portion of body.

Greatest body depth at origin of rayed dorsal fin, depth 0.38–0.44 [0.42]; snout tip to origin of rayed dorsal fin 0.50–0.54 [0.51]; snout tip to origin of anal fin 0.78–0.83 [0.79]; snout tip to origin of pelvic fin 0.50–0.58 [0.52]; snout tip to anus 0.75–0.79 [0.76]; origin of rayed dorsal fin to hypural joint 0.55–0.59 [0.57]. Rayed dorsal fin pointed, less so with increasing age; anteriormost rays 3.7–4.7 times length of ultimate ray. Pectoral fin pointed; length of pectoral fin 0.20–0.23, extends to or slightly beyond vertical through origin of pelvic fin. Pelvic fin pointed, length of pelvic fin 0.22–0.27, reaches approximately two-thirds to three-quarters distance to origin of anal fin. Caudal fin forked. Adipose fin well developed. Anal fin emarginate, anteriormost branched rays twice length of ultimate ray. Caudal peduncle depth 0.11–0.13 [0.12].

Head distinctly pointed, head length 0.31–0.37 [0.31]; upper jaw longer; mouth inferior; lower jaw triangular in ventral view; snout length 0.30–0.35 [0.34]; 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 0.30–0.35 [0.31]; adipose eyelid present, with vertically ovoid opening over center of eye; length of postorbital portion of head 0.36–0.41 [0.38]; gape width 0.24–0.31 [0.30]; interorbital width 0.40–0.45 [0.42].

Pored lateral-line scales from supracleithrum to hypural joint 44 to 52 [49]; all scales of lateral-line pored, canals in scales straight; 4 to 8 series of scales extend beyond hypural joint onto caudal fin base; 12 to 15 [15] scales in transverse series from origin of rayed dorsal fin to lateral line, 7 to 9 [9] scales in transverse series from lateral line to origin of anal fin; scale margins slightly ctenoid, more so ventrally.

Dorsal-fin rays ii,9 [ii,9]; anal-fin rays ii,10–12 or iii,10 [ii,12]; pectoral-fin rays 14 to 16 [14]; pelvic-fin rays i,8–9 [i,8].

Total vertebrae 30 (1), 31 (58), 32 (1).

COLOR IN LIFE.—Overall coloration bright silvery, median and paired fins with slight reddish tint.

COLOR IN ALCOHOL.—Overall coloration of specimens retaining guanine on scales golden or silvery golden, darker on dorsal portions of head and body. Specimens lacking guanine on scales tannish-brown to brown. Middorsal line quite dark from rear of rayed dorsal fin to upper portion of caudal peduncle. Anterior margin and distal portions of rayed dorsal fin dusky.

DISTRIBUTION.—Rio Branco and Rio Solimões (Figure 37).

COMMON NAME.—Peru: Julilla (Ortega and Vari, 1986:11).

MATERIAL EXAMINED.—85 specimens (42, 55.5–121.5)

BRAZIL. Roraima: Rio Branco, USNM 267323, 1. Rio Branco at Bem Querrer, USNM 267352, 28 (15, 55.5–71.4); NMW 68862, 1. Rio Uraraicoera, opposite Ilha de Maraca, USNM 267956, 4 (112.7–127.9); MZUSP 32256, 10. Rio Branco, Marara, MZUSP 28723, 6. Amazonas: Ilha da Marchantaria, USNM 229171, 2 (84.9–89.2). USNM 267328, 1 (86.2). Fonteboa (= Fonte Boa), MCZ 60886, 3 (103.5–113.8, paralectotypes of Curimatus simulatus; out of MCZ 20198); MZUSP 21032, 4 (98.2–107.2). Rio Solimões near mouth of Rio Jutai, MZUSP 20991, 1 (97.8); MZUSP 21015, 2 (98.8–99.0). Vicinity of Manaus, MZUSP 28722, 4 (2, 81.4–98.3). San Paolo (= Saõ Paulo de Olivença), MCZ 20221, 3. Hyavary (= Rio Javari), MCZ 20233, 1.

PERU. Loreto: Iquitos, Río Nanay, USNM 167803 (formerly IU 17851), 2 (89.3–89.7, paratypes of Psectrogaster cisandinus); USNM 167834 (formerly IU 17850), 1 (121.5, holotype of Psectrogaster cisandinus). Río Nanay near Llanchama Cocha, NRM SOK/1984324.4055, 1. Río Nanay near Quebrada Agua Negra, NRM SOK/1984326.4044, 3. Río Itaya, lower portions, USNM 280425, 1. Lago Cashiboya (near Contamana), USNM 167805 (formerly IU 17851 in part, paratype of Psectrogaster cisandinus), 1 (84.5); CAS 57144, 1 (80.9, holotype of Lambepiedra alleni, paratype of Psectrogaster cisandinus, formerly IU 17851). Ucayali: Río Yavari, near Petropolis, USNM 261437, 1. Río Ucayali, Masisea, USNM 261483, 2 (87.2–97.4). Masisea, USNM 261472, 1 (113.7).