Eastern Mosquitofish
Gambusia holbrooki
Southern Platyfish
Xiphophorus maculatus
About
The Southern Platyfish is a small, tough livebearer, meaning females give birth to live young instead of laying eggs. It comes from slow-moving canals, ditches, and warm springs from Veracruz, Mexico, to northern Belize. But aquarium releases have carried it far beyond that range, from Hawaii to Puerto Rico.
Also known as: platy, southern platy, green lantern platy, moonfish, gold twinbar platy
How to tell it apart
Many Xiphophorus fish, including its close relative the green swordtail, have a dark stripe running along the side of the body. Wild Southern Platyfish do not have this stripe. That is the clearest way to tell a plain wild fish from its striped relatives.
Appearance
Wild Southern Platyfish are plain and dull in colour. Males have a slightly more pointed tail fin than females. A male's anal fin has changed into a narrow, rod-shaped part used for breeding, while the female's anal fin stays fan-shaped. Breeders have made many bright aquarium colour forms, including orange, red, yellow, and black and white, but these are not how the fish looks in the wild.
Did you know?
The Southern Platyfish has three different sex chromosomes, W, X, and Y, instead of the usual two. This gives it one of the most complex sex systems known in any fish.
Log it in Into the Blue
Describe what you saw and we name it, then keep every species you find in your Oceandex.
