Guppy Fish Breeding and Fry Care
Ask any aquarist who has guppies whether it is just to have them or they breed them how to breed guppies, while chuckling they will tell you that if you have a male and a female in your tank congratulations your female is already pregnant. As strange as it may sound, guppies are exactly that easy to breed. They will breed in poor water quality and being underfed. The problem is if you have those conditions in your tank, the pregnant female may not survive to give birth, or she may terminate her pregnancy and you will not have fry, or the fry will not survive. Let’s take a look at how to ensure a healthy breeding, pregnancy and birth.
Water Quality
If you ever read forums to try to figure out what is going on in your tank or you are in any groups for aquariums or species related fish on facebook, the first thing anybody ALWAYS ask is your water parameters. The reason for this is because something as simple as your pH being off could cause several issues inside your tank with a very simple solution. Your water quality plays a huge role in the health and well-being of your fish just as the air we breathe in daily plays a huge role in the health and well-being of humans.
Guppies being as hardy as they are have a large area of parameters that they will do well in and thrive. Nitrites must ALWAYS be 0ppm are as close to that as possible. You may see small amounts from time to time in your tank as your tank may be going through mini cycle or just may need a water change. Nitrates should be under 40 ppm. Anything over that and you need to at least start with a water change. Your water hardness should be around 75-125 ppm, however they can survive in softer water just prefer those ranges. Alkalinity (KH) should be around 80-150 ppm and your pH 6.8-7.8 ppm.
Water temperature is important also. On average your water temperature for guppies should be somewhere between 72-78 degrees F. Towards the end of the pregnancy when your female is in labor having water temperature 77-79 degrees F will help her with labor pains by relaxing her stomach muscles.
Feeding
You should always be feeding your fish a well balanced diet even if you are not breeding them. It is more important to ensure they are having a well balanced diet when you are breeding them as being pregnant takes a great deal of effort and birthing takes a real toll on the body. The healthier the fish, the better the birth will go ensuring mom and fry are all healthy.
Generally you can feed your fish a high quality flake food
daily or twice a day. Guppies are omnivores meaning they eat meat and vegetables. A flake food that has meat and vegetables such as API Tropical Flakes will make sure that your fish are getting the proper nutrition with minimal effort on your part. This would be equivalent to a super chef salad for your fish load with everything. However, eating this daily even once a day will get boring and you should be mixing it up for them. Guppies will also eat bloodworms (frozen or freeze dried), brine shrimp (live or frozen), daphnia, cucumbers, zucchini, and lettuce. You may still feed flake food to them even with these additions, just will need a smaller portion as not all guppies will enjoy these particular snacks.
Pregnancy
Now that your female is pregnant, you wait. A female is pregnant generally for 28 days. They can go longer up to 31 if conditions are not right or they are stressed or unhealthy. During this time make sure that you are doing proper water changes and keeping their water parameters as close to constant as you can. Feeding is important also. To help keep stress down, make sure your female or females have areas to go in the tank to get away from other fish, especially the last week of their pregnancy when they really like to start hiding. It is also important to make sure you have 1 male to at least 3 females in your tank so that the male is not constantly aggravating your female and stressing her out.
During the pregnancy, you will notice your guppies stomach grow larger and larger. You will also notice her gravid spot (black area at the end of her stomach) growing larger. As the pregnancy progresses, you may notice that her gravid area will start to lighten up. As your female is getting closer to term, you may notice she may be a bit aggressive and grumpy with other fish. She may start nipping at them should they get too close to where she is, chase them across the tank or fight each other for several seconds. This is her area that she wants privacy in and is protecting it. A few days before your female gives birth you will start to notice that her round, plump belly will start to look more square. This is an indication that you will soon have fry in your tank. Within hours of delivery you may notice that your guppy will slow down on her eating or not eat at all. She may even come out of her hiding area, suck in the food and then spit it out a few times before going back and hide. This is common and no need to be alarm.
Labor and Birthing
As your guppy is going into labor you will start to notice her acting a bit strange but common for labor. Your female may start pacing the tank. Up and down on one wall or across the tank. She isn’t moving as fast as she had normally been. Your guppy may also be hanging out by the heater as the heat is helping to relax her stomach muscles. If you are watching close enough you may be able to see contraction in her stomach. As she is getting closer to delivery, you may also notice that she seems more tolerable of other fish in her area unless they are hitting her in her side. Your fish will notice hormone changes in other fishes. If you get your guppies as adults, chances are they know what the smell of a fish in labor is and will begin to hit your pregnant fish in the stomach in hopes of putting her into labor. Reason why is so that they can eat the fry. Yes, this is a real concern and happens often. You have three options on how to save as many fry as possible from each birth.
Option 1
Have a tank full of plants. Make sure that there is many areas where only tiny fry can hide in that no adults can get to. A female can possibly drop over 100 fry so the more small areas the better.
Option 2
This option and well as option 3 may be a bit trickier as it can cause stress in most females. You can get a birthing box that attaches to the tank. Once you suspect that she is in actual labor you can put her in this box. It is a two section box. You place the female in the top section. There is a slotted divider that the fry will fall down once born and hopefully stay in until your female is finished giving birth. Once she is done you can remove her from this box and put her back into the tank. However, you put her in there too soon it could cause her too much stress. Just keep a close eye on her in this box.
Option 3
You can have a smaller tanker setup and ready to go to act as a 
birthing area for her. This tank will be the same temperature and water parameters as the main tank and will be heavily planted with live or fake plants for the fry to hide in. You remove the female when she is done giving birth to the main tank and leave the fry. Once again being isolated in a tank alone could cause your female to stress out so it is important to keep an eye on her.
During actual birth, you will notice that your guppy will start moving backwards. Her tail will also start going up. If you are lucky enough to be seeing this, watch closely as you may start to see the birthing of several fish. Depending on how many fry your female is carrying will depend on how long she will be birthing. This can go on for several hours. Once she is done giving birth your female will be hungry and tired. She will need an area where she can rest for a day or two. This can be in a main tank hiding in plants.
Fry Care
My guppy gave birth! Now what?! First don’t panic, it’s just new born babies. Easier said than done right? Especially after reading everything. First, you need to decide just how important it is for all or most of your fry to stay alive. If you are ok with losing several to possible the entire batch, then you can leave them in your main tank with some plants for them to hide in. In this case, nature will take it’s course and it will be survival of the fittest in your tank. It is awful but that is nature. If you want to save as many as possible you have two options.
Option 1
Leave the fry in the main tank with as many small hiding spots as you can possible have. Just remember at feeding time to feed close to where the hiding spots are so that your fry to do not have to venture far away to eat and they do not have to fight the bigger fish for food. This should help you keep most of the batch alive. The bigger fish will eat anything that can fit in it’s mouth, so your fry are not safe without many hiding spots for 1-6 weeks.
Option 2
Have a separate fry tank that you can transfer the new fry into after birth. This fry tank does not have to have plants on anything on the bottom. It does need oxygen and a heater to keep them warm. Unless you are an experienced aquarist, a fish tank filter should be kept in this fish tank also.
Which ever method you choose, you need to make sure your guppies stay warm and are well feed. So, what do you feed this incredibly tiny fry? You can feed them the same flake food that you feed your adult guppies. Only, it needs to be in a powder form. You may also feed them freshly hatched baby brine shrimp or foods made especially for new fry. It is important to feed them at least three times a day. 4-6 would be optimal if you are capable of that many feedings. A fish stomach is about the size of their eyeballs. A new fry will grow quickly therefore needing to consume food more often than an adult guppy. No different than a human newborn needing to feed several times a day. It’s hard work growing up. After they are about a week to two weeks old depending on how fast they are growing, you can introduce frozen brine shrimp to them or daphnia. If you choose to give all of your fry a better chance at surviving by having them in a separate tank, you can introduce them back into the main tank when they are big enough to not fit in the adults mouths of any fish you have in your tank. This is generally 3-6 weeks depending on the conditions and feeding of your fry tank. When they are about 3 months old their colors should all be showing and are ready to start breeding themselves.
Check our articles about Guppy Tank Setup or Guppy Fish Care.