Family Poeciliidae Bonaparte 1831 (Fig. 4G). Livebearers, Poeciliids; Olominas, Aluminas, Bobitas, Chimbolas, Pepescas

Description: Body elongate to moderately deep; up to 20 cm in length, usually less than 10 cm; mouth short, wide, terminal to superior; predorsal profile usually straight; lateral line reduced to a series of individual pits alongside of the body; pectoral fins high on the sides of the body; pelvic fins originate behind pectoral fin base, under pectoral fin rays; males of most species have a gonopodium (an elongated structure composed primarily from the 3rd–5th anal rays), which facilitates internal fertilization caudal fin usually rounded (Robertson & Allen 2015, Nelson et al. 2016, Angulo et al. 2021). Distribution: Freshwater and brackish water; eastern USA to South America and Africa (including Madagascar) (Nelson et al. 2016). Eleven genus and twenty-one species in Nicaraguan freshwaters.