Scientifically known as Xiphophorus maculates, these orange and black platys also go by Mickey Mouse platy, southern platy and moonfish. Males of this species are significantly smaller than the females; males reaching up to 1 ½ inches and females 2 ½ inches. They begin to breed at a young age of only a few months old, and then never seem to stop. The female can produce a new batch of babies about every month. Like other platys, Mickey Mouse fish breed easily. The female only needs to mate with a male once to give birth for several months in a row.
Calculate the age of your fish if possible. If you know your Mickey Mouse fish are over the age of 5 months then you know they are old enough to breed.
Determine if you have a male and female Mickey Mouse fish. If your fish are adults, based on age, and there is a significant size different then you likely have a male and female. If you have a male and female adult Mickey Mouse fish, the female is likely pregnant, or will be soon.
Watch the female for a growing belly. She will produce about 50 babies with each birth--she will be noticeably pregnant within a week or two of fertilization.
Look carefully at the female's belly if she is growing rounder. At first, you may see what look like dots inside her belly--these are the eggs. Toward birth, you may see the fry moving around inside the mom.