Information on Breeding Live Bearing Fish
Live bearers have the unique trait of caring the eggs inside them till they hatch then giving birth to live fry. This means that there is no need to find ways to protect the eggs from predators. However once the fry have been born their lives are threatened right away by their own mother who almost always develops an appetite for her babies and will try to eat them right after giving birth. There are 2 good options to choose from to protect the fry from the mother at birth. One option is to use a commercial breeding trap. Breeding traps are special containers with 2 or more sections that are divided by slotted v shaped divider that allows the fry to fall through in to a separate section from the mother. The other option is to provide several plants ne rocks in the tank that can act as hiding places for the fry when they are born. Providing the hiding places is better for the mother as it will cause less stress on her but some fry might not find a hiding place quick enough so usually less fry are saved when using plants over a commercial breeding trap.
Raising the fry is not very difficult. When they are first born they should be separated from the adults to protect them. They can be fed crushed flakes, baby brine shrimp and commercial fry foods. Once the live bearing fry have grown large enough that they won't fit into the mouths of the adults they can be placed in the tank with the adults. Wait at least 4 weeks before considering placing them back in the tank with the adults.
Guppies will typically give birth to between 24 and 48 fry depending on the size of the mother. The gestation period is usually about 28 days. When they are about ready to give birth the female guppy will be very large and will have a black spot close to her anal fin. This black spot is called the gravid spot. Selective breeding of fancy guppies can produce a wide range of color variations.
Platys will typically give birth to between 30 and 60 fry depending on the size of the mother. The gestation period is usually between 5 and 5 weeks. When they are about ready to give birth the female platy will be very large and will also have a black spot close to her anal fin similar to guppies. Selective breeding of platys is a good way to produce vibrant color variations.
A large female molly is able to give birth to around 80 fry while smaller females may give birth to 40 or less fry. The normal gestation period for a molly is between 5 and 6 weeks. On lighter colored mollies a gravid spot will be visible close to the anal fin when they are ready to give birth. The gravid spot is not visible on black mollies so only the size of the molly can be used to predict when she is almost ready to give birth. Mixing different colors of mollies can produce unique color variations.
A large female swordtail can give birth to around 80 fry while smaller females may give birth to 40 or less fry. The normal gestation period for a swordtail is between 5 and 6 weeks. On lighter colored swordtails black spot or gravid spot may be visible close to the anal fin when they are ready to give birth. The gravid spot will not be able to be seen on black swordtails so only the size of the swordtail can be an indicator as to when she is almost ready to give birth. Mixing different colors of swordtails can produce unique color variations.