Family Polynemidae Rafinesque 1815 (Fig. 3M). Threadfins, Tassel-Fishes, Bobos; Bobos, Barbudos

Description: Body elongate, compressed; up to 46 cm in length; snout short, conical, translucent, overhangs mouth; mouth moderate, inferior, with bottom lip extending to front, but no top lip; tooth bands of top jaw touching in center; eyes large, longer than snout, with fatty cover, at front of head; preopercle serrated; scales rough; lateral line extends onto caudal fin; pectoral fin low on side, divided in two portions, the upper portion a normal fin, with 12–19 rays, the lower portion, under gills, with 3–16 long, free rays; two well separated dorsal fins, the first one with eight spines and the second one with one spine and 11–15 rays; pelvic fins well behind the pectoral fin base, under the first dorsal; anal fin base short, with three spines and 10–18 rays; caudal fin forked (Robertson & Allen 2015).

Distribution: Marine (often brackish), rarely freshwater; worldwide, all tropical and subtropical seas (Robertson & Allen 2015). One genus and three species in Nicaraguan freshwaters.