Phallichthys amates

Merry widow livebearer
A male
A female
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cyprinodontiformes
Family: Poeciliidae
Genus: Phallichthys
Species:
P. amates
Binomial name
Phallichthys amates
Synonyms

Poeciliopsis isthmensis

Phallichthys amates, the merry widow or merry widow livebearer, is a livebearer fish from Central America, the largest and most widespread in its genus. Two subspecies range from Guatemala to Panama. Distinguishing features include the dark dorsal fin edge, a stripe through the eye, and an oversized male copulatory organ (gonopodium).