Species: Poecilia velifera, Sailfin molly, Yucatan molly

Poecilia velifera (Regan, 1914)

Yucatan molly

Head and body moderately robust, moderately compressed at rear; head depressed; front nostril not tubular; covering of eye not continuous with skin of head; mouth small, at front, slightly oblique, lower jaw slightly projecting, top jaw protractile; jaw teeth consist of an outer row of large backward curved teeth with expanded tips, and several rows of small pointed teeth; 1 dorsal fin with long base, its origin before pelvic origin, 16-20 rays, fin enlarged in both sexes, high and sail-like in male; pelvic origin well behind pectoral base, near anal fin; tip of pelvic fin of males swollen, elongate; pectorals high on flank, 5th ray not scalloped in male; anal fin 9, origin well behind dorsal fin origin in both sexes; 3rd anal ray unbranched; anal fin modified in male to form an elongate sex organ, that organ relatively short, with straight tip that has small spines & a fleshy palp; tail base relatively narrow; tail fin rounded, without elongate sword; scales smooth and relatively large; 26-27 lateral scales, 20 around tail base.