Pimelodus punctatus

Pimelodus punctatus (Meek & Hildebrand, 1913)

Megalonema punctatum Meek & Hildebrand, 1913: 77. Type locality: Río Tuyra, Boca de Cupe, Panamá. Holotype: FMNH 7577. Paratypes: USNM 78279 (2).

Megalonema robustum Meek & Hildebrand, 1913: 78. Type locality: Río Tuyra, Marriganti, Panamá. Holotype: FMNH 7578 (Ferraris, 2007).

Diagnosis. Pimelodus punctatus differs from P. coprophagus in having the predorsal length less than 38% SL (35.1–38.0% SL vs. 39.0–42.7% SL) and head length less than 27.0% SL (23.1–26.5% SL vs. 27.1–30.7% SL); it differs from P. yuma n. sp. in having a smaller interorbital width (26.0–32.9% HL vs. 36.2–42.8% HL) (Fig. 11) and a wider mouth (36.0–41.1% HL vs. 27.7–34.9% HL); it differs from P. blochii in having a predorsal length less than 38.0% SL (35.1–38.0% SL vs. 38.1–41.6% SL); it differs from P. grosskopfii and P. crypticus n. sp. in having a shorter adipose fin (17.6–20.9% SL vs. 23.4–28.8% SL) and a greater adipose-dorsal distance (15.1–19.4% SL vs. 9.2–14.9% SL). Additionally, it differs from P. blochii, P. crypticus, and P. yuma in having dark spots along the body (vs. without dark spots or stripes).

Description. N=45. Morphometric data presented in Table 2. Body deeper than wide; roof of cranium ornamented with smooth, small (but visible) granules and striations. Eye diameter less than interorbital width. Snout convex, projected beyond mandibular symphysis. Mouth subterminal, when closed, 3/4 of premaxillary tooth patch exposed, those teeth conical, small and narrow. Fontanel opened from mesethmoids to frontals, terminating at vertical through posterior third of eye. Maxillary barbels reach bases of middle caudal-fin rays; inner mental barbels reach pectoral-fin bases, outer mental barbels reach almost to pelvic-fin bases.

Dorsal fin lepidotrichia II,6; the first a spinelet narrow and angular, spine strong, slightly curved and sharppointed. Adipose fin short, its margin rectangular, anterior apex at vertical through middle of anal-fin base. Pectoral fin I,9–10; spine strong, sharp-pointed and forming slight arc. Pelvic fins i,5; with first branched ray longest, inserted at vertical immediately posterior to base of last dorsal-fin ray. Anal fin iv,8; first branched ray longest. Caudal fin i,15,i; forked, lobes pointed, dorsal lobe longer than ventral.

Lateral line complete, extending beyond caudal-fin base half way out middle caudal-fin rays. Cleithral process extensive, strong, triangular, posterodorsal margin convex and ventral margin straight. Apparently without sexual dimorphism.

Color in alcohol. (Fig. 10) Body tan, head and dorsal region slightly darker; lateral line without stripe or color that highlight it, ventral region light tan. Some individuals without spots; those that show pigmentation have small dark spots uniformly distributed, also covering head, but not the fins. When no spots present, the dorsal spine has dark spot at base. All fins yellow, lighter distally, margins of dorsal fin black; ventral lobe of caudal fin without dark diffuse band. Upper margin of adipose fin hyaline; dorsal surface of maxillary barbels tan.

Distribution. Present in the Tuyra and Chagres Rivers in Panamá, and the Atrato and Baudó Rivers in Colombia (Fig. 4).