Species: Poecilia vivipara, Southern Molly

Poecilia vivipara Bloch & Schneider, 1801

Southern 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, with 1-3 points; 1 dorsal fin with short base, its origin behind pelvic origin, 7-9 rays, elongate 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 8-10, origin at or a little before (female) to a little before (male) dorsal fin origin; 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; 24-27 lateral scale rows; scales around tail base 16.

Yellowish grey-brown above; yellowish to white below, belly and cheeks silvery white; usually with a large black spot (bigger and more obvious in small fish), bounded at front and rear by pale areas on upper part of side of body under or a little before origin of dorsal fin in both sexes; dorsal fin usually with 1-2 conspicuous black stripes or line of spots near its base, outer part of fin yellowish in male; tail fin with yellow base and dark edge, often a pair of blackish spots at upper and lower base of fin, those spreading along its margins. Juveniles with long dark stripes on sides.

Reaches 7.2 cm.

Hypersaline lagoons to salt, brackish and (rarely) fresh water.

Depth range: 0-2 m.

Venezuela to Argentina; introduced to Puerto Rico and Martinique.