Why Do Guppies Eat Their Babies? How To Prevent It?

why do guppies eat their babies?
Guppies are popular among aquarists owing to their attractive colors, alluring looks, low maintenance, and facile to care. They are prolific and breed readily; if you are a guppy owner, you for sure know that they are not good parents and are infamous for eating their offspring. You might have seen the mother guppy devouring on fry just after giving birth! Why do guppies eat their babies?
If you wish to breed guppies and have a big guppy community, then you would want to know why do guppies eat their babies? How to prevent guppies from eating their babies?
In the wild, despite being eaten by their parents and the other species, guppies thrive. However, in a confined space such as an aquarium and a garden pond, the hobbyists need to adopt some means to protect the young from their parents and other species. Of course, there are ways to prevent or reduce the chance of all the guppy fry from eaten by their parents; before going into detail about the prevention, let us find out why do guppies eat their babies!

Why do guppies eat their babies?

Although guppies are a peaceful species and easy to look after, when the guppies begin to reproduce, things get a bit nasty and even horrific for a novice hobbyist and some experienced hobbyists.

Most of us believe that all the animals are protective of their offspring, or at least we don’t expect the parents to eat their offspring most of all by the mother; with such notion, we get perplexed and horrified when we witness the mother devouring her babies.

Most animals are protective about their babies; however, some animal species such as lizards, snakes, even cuckoos desert their eggs unceremoniously and crawl away or fly away or swim away. However, some species take one step further by eating their babies.


Filial Cannibalism


Do guppies die after giving birth

The propensity of animals to eat their offspring is called “filial cannibalism.” Parental care is an essential trait that increases the chances of offspring survival and the fitness; according to the conventional human mind, nurturing, guarding, grooming, etc., are the ways to protect one’s offspring.
However, abandoning offspring and filial cannibalism is also a form of parental care, not cruel nor a perversion; cruelty or perversion comes with the mind. Therefore, it is associated with humans, not animals.
Over-population threatens offspring survival due to the spread of infections and limited resources; hence, the parent ensures the genetically strong offspring gets the chance to survive, which is a form of tough love.
All said and done, the purpose of all living creatures is to reproduce their offspring so that the species continues to exists; it is purely existential. The exceptions are the humans; the purpose goes beyond the continuation of the species survival; we have the possibilities to rise above and go beyond this mere three-dimensional existence; whether we are utilizing this opportunity or not is entirely another scene! I guess here we have gone off the topic!
Now, coming back to the subject of why do guppies eat their babies, a female guppy can give birth to up to 200 free-swimming juveniles in a matter of few hours. All the newborns are not fully developed; most of them are premature, underdeveloped, unhealthy, or stillborn. To provide an optimum supply of oxygen and nutrition to the healthy specimens, the mother guppy and the other adult members eat the weak and unhealthy babies.
For example, Panda often gives birth to twins; she will choose the strong cub and abandon the other. The principal food of Panda is Bamboo; it eats tons of it to derive nutrition, it cannot produce enough milk to support both the cubs; in case she chooses to feed both the cubs equally, neither of them will stand a chance to grow up to be fit and strong Panda, most probably, they both will die. Abandoning one offspring to supply nutrition to the healthy and strong offspring is an ultimate form of tough love.
Similarly, the mother guppy by consuming the weaker offspring gives a chance to the healthy guppies to survive.

Stress – a cause why guppies eat their babies:

Some scientists say stress is also a reason why do guppies eat their babies. Filial cannibalism occurs in response to the stress created during pregnancy and labor, and by consuming its offspring, the mother guppy enhances its self-preservation instinct. Even so, it’s not a sufficient reason why do guppies eat their babies, as the guppies living in a peaceful condition still devour their newborns. I would give the benefit to its genetic memory.

To maximize reproductive success:

Parents consuming their offspring maximize their lifetime reproductive success rate; consuming their babies replenishes their fat storage and individual fitness. It is called parental investment theory is a mechanism by which the parents gain energy and nutrients to reinvest into the future reproduction, ultimately increasing the net productivity rate in species continuation.

How to prevent guppies from eating their babies?

There are different ways of preventing guppies from eating their babies; one thing common in all the methods is adapting the technique of separating the babies from the adult guppies.

Moving the pregnant guppy to a breeding tank

The best method to prevent the adult guppies from eating the baby guppies is to prepare a separate breeding tank and move the pregnant guppy into it. Baby guppies are palatable to their parents and all the other adult members in the habitat, including the other adult guppies and the other species living in the tank if it is a community tank. 

This scenario lowers the chances of baby guppies’ survival rate. By merely separating the pregnant guppy into another tank increase the chances of babies’ survival rate. You can further increase the survival rate by preparing the breeding tank appropriately.

Water Parameters

The primary factor to address in a breeding tank is establishing appropriate water parameters conducive to baby guppies; a temperature range of 77 to 79°F (25 to 26°C) with water pH 6.8 to 7.8 and water hardness 8-12dGH. The ammonia and nitrites should be 0 ppm and nitrates maximum 10 ppm. Running a fishless cycle is an essential part of the breeding tank setup.

Clean water

A filtration system is essential to keep the water clean; you can use a simple sponge filter with an air stone. Despite the filter, you will have to clean the tank regularly and do a regular partial water change to keep the water parameters in check. 


Guppy fish needs 12 hours of light and 12 hours of darkness. Lack of light or dim light will result in unhealthy stock; baby guppies with insufficient light develop deformities. By simply mounting 30 to 40 watts fluorescent lamp or LED lights above the breeding tank would suffice. Most LED lights come with a timer so that you wouldn’t miss out on the time duration.

Plants for the breeding tank

Though some hobbyists prefer to have a bare breeding tank, it is wise to have some floating plants, preferably mosses such as java moss, which shelters the newborns and protects them from their mother guppy. 

Moreover, java moss is home to infusoria, the first fry food. For the first few days, fry nourish themselves from infusoria and the planktons; hence, it is crucial to have plenty of mosses floating in the fry tank; you may also supplement it with homemade or commercial infusoria.


You would need to feed right for Guppy fry to grow healthy and study.

Guppy fry needs infusoria and artemia such as brine shrimp, daphnia, etc., to grow healthily and wholly; supplementing high-quality commercial fry food will significantly help.


Related Readings:

Do Guppies need a filter?

How many guppies per gallon?

Can guppies live in cold water? What is the ideal water temperature for Guppies?

Creating a lot of hiding space


Another way to protect the guppy babies from their parents without investing in a separate breeding tank is to provide plenty of hiding spots for your guppy fry. You can do this by planting sufficient live aquarium plants, incorporating decoratives such as driftwood, caves, tubes, rocks, swirls, etc.

Guppies are viviparous, not egg layers; they give birth to free-swimming babies; hence they are not as vulnerable; they can quickly locate a secure spot and elude the adult members in the habitat.

Live aquarium plants, rocks, and other decoratives ensure guppy fry enough cover to dodge from the adult guppies and other species. 

Aquarium plants are ideal as they are the home to Infusoria, the first fry food; hence, along with providing shelter, they nourish the fry to grow healthy.

Live plants keep the water well oxygenated and clean by absorbing nitrates and other toxins from the water.

Breeding net or box

Placing pregnant guppy when she is about to give birth; the gestation period of guppy fish is around 25 days (21 to 30 days). 

It is better to move her to the breeding box only when she is about to give birth; staying in a confined environment will stress the mother guppy leading to some birth complications; eventually, the mother guppy might die. Also, the mere act of moving her to the breeding box can stress the mother guppy; a stressed guppy may deliver many unborn babies, deformed and under-developed fry, etc.

A guppy can give birth to up to 200 babies; however, generally, it can range from 20 to 50 babies in a home aquarium environment; she delivers one at a time in succession with pauses between the group of babies; the labor may last for few hours depending on the condition of the mother guppy; however, if she is stressed it can stretch to even days.


You would want to remove the mother guppy from the breeding box and supply her with a nutritious diet to recover from the labor. Otherwise, she will devour on her newborns to replenish herself of nutrition in preparation for the subsequent reproduction.

It is safe to introduce the baby guppies into the main tank when they are large enough to not fit into the mouth of adult guppies or other inhabitants in the tank; it will be about six weeks by them.

Why do guppies eat their babies? – Final thoughts:

Irrespective of why do guppies eat their babies, every guppy breeder should accept nature’s way and prepare to adopt an appropriate method to protect the guppy babies from the adult members depending on the budget, time, and space availability.

As guppies do not have any maternal instinct, or at least according to the human acumen, it is entirely up to you to protect the baby guppies if you intend to build your guppy stock.

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