Breeding tropical fish can be a lot of fun. Try your luck at breeding livebearers such as guppies or swordtails.
Breeder Box or Breeder Net
5 or 10 gallon tank for the baby fish or a tank divider that you can use for your main tank.
A pair - 1 female and 1 male
Two of the more popular tropical fish for beginners has to be Guppies and Swordtails. Guppies and Swordtails are livebearers which means that their babies come out swimming. Like most livebearers, there is not much to getting your guppies or swordtails to breed. If you have a male and a female then you will eventually have a pregnant female. The gestation period for livebearers is usually 28 days but can range from 20 to 40 days.
Place the male and female in the same tank together and they will soon mate. You are probably asking, how can I tell when the female is pregnant? When a female guppy is pregnant she will develop a dark triangular shaped gravid spot near her anal vent. This will get larger and darker as the pregnancy progresses. While you are waiting on the female to develop the babies it's time to make sure you are prepared for the delivery. We use plastic breeder boxes and always have without any problems. A breeder box is a small box plastic box about 4 inches long by 3 inches wide and 4 inches deep.
There is a removable "V" shaped trap in it which serves to separate the mother from the babies. When the mother fish has babies they fall through the slot in the "V" into the bottom of the box. After the mother is finished having babies, you can remove the "V" trap and the mother so that they babies have more room to grow. Some people have had bad experiences with breeder boxes and now only use a breeder net. It is also a good idea to purchase some real or plastic breeding grass for the top of the aquarium. The breeding grass is just in case the mother gives birth before you have a chance to put her in the breeder box. The young babies instinctively will swim to the top of the aquarium and the breeder grass provides a great hiding place so they won't get eaten by the bigger fish in your tank.