Platy fish belong to the genus Xiphophorus, which includes two species: the southern platy and the variable platy. Generally, variable platy fish is slightly larger than southern platy fish.
These two species have been interbred so much that they are difficult to distinguish and have created many size varieties.
I keep many varieties of platies, and the largest size platy I’ve ever had was 2.4 inches long. But I’ve seen much larger platies in fish exhibitions.
The average size of an adult platy fish is 2-3 inches in length and 0.4 inches in width, but this can vary depending on their sex, genetics, diet, water quality, temperature, and living conditions. Female platy fish tend to be larger than males, reaching up to 3 inches, while males only reach up to 2 inches long.
To ensure optimal growth for your platies, you must provide them with a healthy environment and a balanced diet.
Platy fish require a tank of at least 10 gallons of water for every 1 inch of fish. This means a tank of adult platy fish should have around 20 – 30 gallons of water.
A well-balanced diet with high-quality foods will help your platy fish grow healthy to its maximum size.
Platy fish are livebearers, meaning they give birth to live young instead of laying eggs. So female platies look much bigger than their normal size when pregnant. They often breed, producing 8-30 fry (baby fish) at a time.