- Differentiation with similar species:
- Poecilia latipinna: dorsal fin with 12-14 spiny radiums; extended, with aspect of sail . Size: 9-10 cm long.
- Poecilia velifera (Yucatan molly): dorsal fin major than P. latipinna: 18-19 spiny radiums; extended, with aspect of fan. Size: 12-14 cm long.
- Look: the sailfin is only in the male, the females have smaller dorsal fins.