A guide on breeding The “Millionfish”
You just purchased guppies, and you notice Wanda’s been getting a little larger. You’re probably thinking uh-oh, my guppy is pregnant! What do I do now? If you have owned guppies, you have probably been in this position before, but for first time owners there are some things you are going to need to know.
Guppies (Poecilia reticulata), or otherwise known as the “Millionfish”, for how quick and easy it is to breed them, can give birth to as little as 5 or well over 100 babies, or fry. After these live-bearing fish give birth, the fry are free swimming within minutes.
Creating a home
It is better to have more than one tank when a female guppy is about to give birth, but if only one is available, there are many strategies to help keep fry safe from hungry guppies when they are born.
A fish net breeder is the most effective way of raising fry in my experiences. This cube shaped net on a plastic frame that hangs is able to share water of the aquarium. Fry can be placed in the breeder if you decide to leave the female in the aquarium to have her babies; you will just have to fish them out. These can be hung around the inside of the tank to house different age groups of fry as they grow until they are large enough to place in the main aquarium.
An aqua nursery is a plastic nursery that hangs on the side of the main aquarium and has 2 separate sections; when fry are born, they drop into the bottom section, and the female will stay in the top. In this bottom section there is a tube that the fry will swim into, and this will lead them into another chamber of the nursery. This tube will not fit the female; the fry will be safe in a separate chamber.
A 3-in-1 breeding trap is another plastic nursery that hangs on the side of the main aquarium and has 2 separate sections. The pregnant female is placed in the top portion of the 3-in-1 right before she is due, and when she has her babies, they will drop down through a slit that divides a top portion from a bottom. I have found this breeding trap to be ineffective when compared to the fish net breeder or the aqua nursery because if the female is left in the top portion for a few hours, the fry may begin to swim back up the slit and will be eaten.
If you choose not to separate a pregnant female or fry from the main aquarium, you can purchase baby fry hideouts – fake vegetation – that float on the surface or can be secured on the bottom of the tank so that fry can hide within. Using this method of not separating the fry from the adults will usually only save a portion of the newborns.
Avoid using tank dividers to divide fry from adults because the fry can fit through the openings in the dividers, and soon all of your fry will end up on the other side with the adults, eaten.
Choosing a safe filter
When fry are present, a sponge filter pumped by an air pump should be used so that they are not sucked into the filter. A powerful filter can pin guppies against the side of the filter inlet. Oxygen entering a sponge filter creates its own suction into the sponge and also oxygenates the water. By using this type of filter, suction is just strong enough to draw particles into the sponge, but does not harm fry. Once a week the sponge should be taken out and cleaned with fresh water by being squeezed and put back in. By having oxygen enter and exit the tube, the device creates a vacuum for particles. Oxygen leaves the tube and bubbles in the water to oxygenate the tank.
The food given to fry and adult guppies differ in consistency, but are similar in health aspects. Fry foods are high in protein for growth, and the consistency is almost a powder so that the fry can digest; for example, try Pure Aquatic Fry Food. Adult food is available as small pellets, super fine or flake food. For higher color clarity in fish, natural color-enhancing pigments can be given. Garlic is often included in fish foods to help eliminate infections while building the immune system. Garlic also attracts finicky fish to eat with garlic drops are placed with food into the tank.
Both fry and adults should be fed 2-3 times per day with amounts that your fish will consume within 2-3 minutes. Do not overfeed – this may kill them. Also, uneaten food will raise the nitrate levels in aquarium water.
Cleaning a tank with adults or fry
Vacuum the bottom of the tank to get debris once a week using an aquarium vacuuming tube. Get the flow of water through the tube started by siphoning the end. While running the tube across the bottom of the tank, be sure you do not suck any fry up.
Continuing to breed
If you are interested in continuing the breeding process, be sure you keep a healthy ratio of males and females. Females reach maturity at 3 months while males become mature at 2 months. Try not to exceed 1 male for every 3 females. Separate the female when she is ready to give birth if you choose this method, and return her immediately when she is done. Be aware that a female can give birth multiple times from only one insemination, even if a male is not present, because females can store sperm.
There are many variations of color, pattern and fin shape to consider when breeding your guppies. Males are much more vibrant and can have different tails such as the double swordtail, top or bottom sword tail, fan tail and veil tail. If you want solid blue tailed guppies with gray bodies, try to have blue tailed parents with gray bodies; gene distribution for fish matches that of people.
Breeding guppies can be a fun and rewarding endeavor; it is the gift that continues to give!
Kendra Jones is a student at York College of Pennsylvania, United States, majoring in both biology and professional writing. She has been a keeper of both freshwater and saltwater fish since 2003 and has been breeding guppies for the past ten years.