There are many reasons for you wanting to know more about breeding guppies. It might be that your guppies are already breeding in your aquarium, you might want to breed some guppies for profit or get a special looking guppy strain in your aquarium to show off.
In this article we will go over all the basics involved with breeding guppies, from identifying males and females, the perfect breeding conditions, the different methods, how to care for your new baby guppy fry and touch upon some health and disease related parts.
Is my guppy male of female?
There are a number of physical characteristics to easily differentiate male and female guppies from each other. For example Size, color, fins and body shape.
Size
Male and female guppies are different in size. Typically male guppies are smaller and more slender than the female guppies. On average the females measure around 2 to 3 inches (5 to 7.5cm) and the males measure 1 to 2 inches (2.5 to 5cm).The size difference between male and female guppies can differ per strain or variety. Therefor size can work as a good indicator, but we need to look at more than just the size.
Body shape
We can also use the body shape to find the difference between male and female guppies. Male guppies will have a longer and and much more slender body shape. When we take a look at female guppies, we will find that they are more round and plump. This will especially be true when the female is carrying eggs as this will make her even more round and plump.
Fins
Another indicator to find out if your guppy is male or female are the fins. The fins between male and female guppies differ in size, with the males having longer en more detailed fins. This is true for the dorsal fin (found on the back / top of the fish), anal fin as well as their tail.
The anal fin, also known as cloacal fin, is located near the back end of the body, close to the tail. If you look at the tail, the anal fin is right next to it, on the underside of the body. On a male guppy the anal fin will have a long and narrow tube with a slightly pointy end. This is called the gonopodium and is used by the male to impregnate the female guppy.
Color
It can be very difficult to determine if a guppy is male or female based on color alone. This means we must use color as a factor together with the other characteristics. In general male guppies have brighter and more intense colors than females. This is especially true for the tail fins.
Gravid spot
The gravid spot can only be found on female guppies. When you’ve found the anal fin on your guppy, you are already close to finding the gravid spot, or lack thereof. The gravid spot is a darker spot just above and to the front of the anal fin. When a female guppy is pregnant, this spot will become more prominent. The gravid spot will not disappear on a female guppy, not even after giving birth, but it might be harder to spot for the untrained eye. Using the other indicators will be a good way to train your eye and make it easier to find the gravid spot. Since it will also be an indicator to see if your guppy is pregnant.
Behavior
Male and female guppies will display different type of behavior in your aquarium. As an example, male guppies will show more aggressive behavior, especially towards other males as they compete for mating opportunities and defend their territory. One should keep in mind though, that each fish has their own personality and their behavior will change depending on their age and social environment.
When you see a male guppy bending its tail and ‘twitching’ it means he is dancing and trying to impress a female. By bending its tail and quickly shaking it, he is trying to impress the female. He does this to show her how colorful and attractive his tail is.
While the guppy is doing its dancing routine, he will also move around. First of all to try and get the females attention, but also to keep an eye out for other males. If another male decides to get close, the dancing male tends to get aggressive. This can lead to chasing, fin nipping and even physical fights if the intruder doesn’t want to back off.
Female guppies in general are more relaxed, and spend more time resting and conversing energy. This is especially true when they are pregnant, as a lot of energy is needed for the babies growing inside her and later giving birth to the guppy fry.
Why do guppies eat their fry?
Countless studies have been conducted on why guppies eat their fry, and some of the given reasons are stress, limited food, and sorting the weak or to replenish their own energy. Another reason would be overcrowding, where the parent is afraid it will get outcompeted by its own fry.
However, a definitive answer has not been given, as guppies in the wild are generally not seen to eat their own fry. Female guppies have been seen to display motherly behavior by trying to hide their young in plants and other structures to protect them from potential predators like bigger fish, birds, insects and crustaceans.
Guppy life cycle
The guppy life cycle can be divided up into multiple stages. From developing as an egg inside the mother, being born as fry, becoming a juvenile, teenager and growing into adulthood.
Gestation period
After the mother guppy is impregnated, the eggs will develop inside her. This is called the gestation period. The eggs will develop into live, free swimming fish in around 28 days. During this time the mother will grow in size and can have trouble swimming.
Since guppies are, unlike most fish, live bearers, they will give live birth to free swimming fish. The mother gives birth to one baby fish at a time, depending on the number of fry, this can take up to a day.
Fry
The young, very small, baby guppies are referred to as fry. The fry are born with an yolk sac on their bellies which they will use as food for the first couple of days. They are also still developing their organs and tissues.
Juvenile
The next stage of a guppies live is called the Juvenile stage. Once the fry are moving into the juvenile stage, they will grow and develop at a much faster rate. They will become more active and curious, and start to explore their environment. During this period, you can also start to identify their biological sex.
Teenager
From around the 2nd to 3rd month, the guppies will become sexually mature and turn into teenagers. The guppies will also start to resemble adult guppies. The guppy will continue to grow and its colors will become much more vibrant and distinctive.The will also start to display more mature behavior for example, males will start pursuing and courting the females. Females can also become pregnant around this time.
Adulthood
Guppies will reach adulthood around the six month period. The fins might still grow a little bit bigger, but the body will not grow anymore. How long the guppy still live from here on out, depends on their genetics, diet and conditions in the tank.
Breeding methods
Actually breeding guppies is not difficult at all. There is a running joke among aquarists that all you need to do is add water. Of course we don’t want out guppies to be stressed out or have no place to hide from the male that will be continuously harass her.
Community / Colony breeding
When you don’t have a lot of space or money to setup a lot of different tanks, community, or colony breeding will be the best approach for you. This means you will have one larger aquarium in which the adults will live and the babies will grow up. This method will result in less guppies, but is a good way to get started and fund the expansion of your breeding operation.
With this kind of setup, it is important to have quite some algae and thickly grown plants and/or moss. Since the adults guppies will pray on the fry, the plants and moss will provide way for them to escape. The plants and moss will also serve the female guppies as a place to rest and get away from the males. The algae will also float as particles trough the water and function as a food source. On top of that, the plants and algae will help filter your water.
Guppy fry will need to be fed frequently, multiple times per day. You also need to make sure it is a small food that can easily be eaten by the fry. The food should also spread throughout the tank, so that the fry wont have to leave their hiding places. making sure your fry get a good amount of food is important for growing healthy fish. As an additional benefit, it will also keep the adults fuller, and as a result they will prey less on the fry.
If you are using any other filter than a sponge filter, it is important to cover the filter intake with either a sponge or something like a stocking. This will prevent the baby fry from getting sucked up by the filter and ending up in the propeller, because lets be honest, that would be horrible!
Selective guppy breeding
To do selective or separate breeding you will need at least 3 to 5 tanks. You will need at least two tanks to keep the females and males separated from each other. Then it depends on how fast and big you want to go. On the smallest range of 3 tanks, your third tank will function as a breeding and growout tank.
The breeding tank, as its name implies, will be used to house a male and female guppy, or breeding pair. As soon as the male has successfully impregnated the female, he should be place back into the male tank. The female should be placed back into the female tank after she is completely done giving birth.
The breeding tank tank also requires something, for example, acrylic yarn that functions as a hiding spot for the fry some the mother fish can not pray on them. After about a week to two weeks you can remove the yarn from the aquarium. This will allow you to take a good look at all the baby new guppies you got!
If you only have a third tank, it is important to also get a breeder box or any other way to divide the tank. While the fry are growing and are moving into the juvenile stage, it is important to start separating the males and females from each other. If you are unsure about a certain guppy, it is better to move it in with the males. This way you wont accidentally end up with all your new females being impregnated by their brother.
If you have more tanks, you can repeat this process faster. Otherwise you will have to wait until the guppies have grown big enough so they can join with the other adults or be sold for profit.
Caring for fry
Caring for the fry is a very important aspect of breeding guppies and will require some attention.
You will need to feed the fry small foods, like crushed up flakes, baby brine shrimp or similar kind of small foods. You should lower the amount of food compared to what you feed the adults, but feed them approximately 4 to 6 times per day. By feeding the fry multiple times per day, you will increase their growth rate.
When the fry are very young, you can also feed them boiled egg as a very nutritious food. You can do this by boiling the egg for up to 10 minutes until it is hard boiled. Let it cool down and peel the egg. Take out the egg yolk and crumble it into small pieces. You can use a fork or just do it with your hands. When feeding egg yolk for the first time, make sure to try and just add a little bit to the tank. This way you can check if your fry will eat it.
As there is a high chance of overfeeding it is also important to keep a close eye on your water parameters. The guppy fry are very sensitive to changes in the water quality. So it is important to do very frequent, small water changes to keep the ammonia, nitrate and nitrite in check.
Guppy fry also need warmer temperatures as the adults can tolerate and to thrive they need a stable temperature. So its best to use a heater, even if the location where you live provides a temperature within the guppy range.