The red platy is the default platy in shops, so it is the easiest form in the group to find. It is a good first fish for a peaceful community tank.
Did you know
The red platy's pigment cell is a modified yellow one. Work on Xiphophorus describes a xantho-erythrophore, a xanthophore in which the red pteridine pigment erythropterin sits alongside the yellow carotenoids lutein and zeaxanthin. The red and yellow forms are closer relatives than they look.
Caring for the red platy
Red platies are peaceful and mix easily with other calm community fish. Keep a small group, with more females than males to ease the pressure on the females, in 10 gal (38 L) or more. A planted tank with open swimming space suits them, and they stay mostly in the middle of the tank.
They are hardy and forgiving. Keep the water neutral to slightly alkaline, at 68 to 79°F (20 to 26°C) and a pH of 6.8 to 8.0. They tolerate harder water well. Feed a varied diet built on flakes with some algae or vegetable content, plus occasional frozen treats.
Females grow a bit larger than males. Red platies bear live young rather than laying eggs, and they breed readily. A female can store sperm and produce several broods from one mating.
Good to know
The red platy's color runs from orange-red to a deep brick. Suppliers add prefixes like Coral or Dark Red with no agreed standard behind them. Judge a batch by how evenly the red carries into the fins, since faded or patchy tails are common in bulk stock. Breeders report that a red line kept away from other colors comes close to breeding true. Even then, intensity varies between siblings in one drop of fry. They also report that crossing red into a patterned line breaks up the solid look in the next generation.
In the wild
The red platy is a breeding line, not a wild pattern. Wild southern platies are drab, and the saturated red is the result of generations of selection in farms and hobby tanks. Trade platies also carry blood from other Xiphophorus species, so a red shop platy is usually a hybrid rather than a pure southern platy. No single breeder or date is on record for the line.
Weekly picks
Tank mates
The red platy is a peaceful, social species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.
2.8 in (7 cm)15 gal (55 L)68–79°F (20–26°C)
2 in (5 cm)16 gal (60 L)68–79°F (20–26°C)
4.1 in (10.5 cm)29 gal (110 L)73–82°F (23–28°C)
2.8 in (7 cm)24 gal (90 L)68–81°F (20–27°C)
5.9 in (15 cm)20 gal (76 L)68–82°F (20–28°C)
3.5 in (9 cm)29 gal (110 L)68–79°F (20–26°C)