Sailfin Molly

Physical Characteristics

Features a deep, compressed body with a very large, sail-like dorsal fin in males that has 13-15 rays. Coloration is typically greenish-gray with rows of small spots forming stripes along the sides. They possess a broad, fan-shaped caudal fin and upward-pointing mouths for surface feeding.

Habitat & Distribution

Native to coastal waters of North and Central America, from North Carolina to the Yucatan Peninsula. They inhabit freshwater streams, ponds, and marshes, but are highly adaptable to brackish and even hypersaline coastal environments such as salt marshes and estuaries.

Size & Weight

Typically ranges from 2 to 4 inches (5 to 10 cm) in length, though wild specimens can occasionally reach up to 6 inches (15 cm). They are very lightweight, usually weighing only a few grams.

Similar Looking Species

The Mexican Molly (Poecilia sphenops) and the Yucatan Molly (Poecilia velifera). The Yucatan Molly is distinguished by a higher ray count (18-19) in its even larger dorsal fin.

Ecological Role

Acts as an omnivore, primarily consuming algae and small invertebrates. They serve as an important prey source for larger fish and wading birds. Currently listed as Least Concern by the IUCN, they are prolific breeders and very hardy in various water conditions.

Identified on: 12/26/2025

Mode: Standard