Poecilia sphenops

Poecilia sphenops is a species of fish, of the genus Poecilia, known under the common name molly; to distinguish it from its congeners, it is sometimes called short-finned molly or common molly. They inhabit fresh water streams, coastal brackish, and marine waters from Mexico to Colombia. The wild-type fishes are dull, silvery in color. The molly can produce fertile hybrids with many Poecilia species, most importantly the sailfin molly. The male mollies generally tend to be mildly aggressive.

Mollies rank as one of the most popular feeder fish due to high growth rate, birth size, reproduction, and brood number.