Family Ophichthidae Günther 1870 (Fig. 2H). Snake Eels, Finless Eels, Ridgefin Eels, Worm Eels, Sailfin Eels, Sand Eels, Spoon-Nose Eels, Viper Eels; Anguilas Culebra, Serpentones, Tiesos

Description: Body elongate, eel-shaped, more or less rounded in cross section; up to 250 cm in length; eyes usually small, situated just above the mouth; snout pointed or nearly so, and frequently overhangs the lower jaw; nostrils widely separated, the anterior nostril normally tubular, the posterior nostril usually within or piercing the upper lip; gill openings on mid-side to underneath the body; gill pouch expanded and reinforced by rays; scales absent; pectoral fins present or absent; tail finless and pointed or conspicuous and confluent with the dorsal and anal fins (Robertson & Allen 2015, Nelson et al. 2016). Distribution: Marine, continental shelf, rarely in midwater, some species in or occasionally entering freshwater; coastal areas of tropical to warm temperate oceans (Nelson et al. 2016). One genus and two species in Nicaraguan freshwaters.