Eating their Young.. Are Livebearers Cannibals?

Author: Delilah from If you are looking for a simple answer, then yes, guppies are cannibals. Adult guppies eat baby guppies, and all guppies will take bites out of immobile or dead guppies they may encounter.

So since adult guppies eat babies, you may be wondering how to keep an adult mother guppy fish from eating her young during delivery. In most cases, you do not need to do anything, because nature has done a great job of ensuring the survival of the guppy species. You see, when a pregnant guppy goes into labor her brain releases a chemical that tells her that she is not hungry.


This way, even though there may be baby guppy fry swimming right in front of her, she will not eat them. All wild guppies have this response during labor. However, as guppies have been taken out of their wild habitat and bred in fish tanks, they have lost their natural environment. In the wild, nature ensures that only the strong and best suited survive.

When it comes to fancy guppies, it is not terribly uncommon to find a female that actually does eat her babies- all of them- just seconds after they are born. Female guppies that eat their babies have a genetic defect. Their brains do not release the hunger- controlling chemical when they go into labor. The reason this strange un- natural behavior can be found in fancy guppies is that human intervention can usually save some baby guppy fish from being eaten, through the use of breeding traps or simply netting the babies shortly after birth. Unfortunately though, some of those baby fish grow up with the same disorder their mother had, and will eat their babies too when they grow up.

You see, in nature if a female has the genetic disorder where she eats her babies, the babies will get eaten and will not survive to carry on the genetic disorder. This is nature’s way of ensuring that the guppies that live to adulthood are the heartiest specimens they can be.

So if you have a female fancy guppy fish that you are using in your breeding program and you find she starts snacking on her babies, you might maybe give her a second chance if she is an amazingly beautiful female, but if she eats her babies again you should not use her as a breeder fish anymore. Doing so would not only diminish the number of baby guppies you get, but would ensure that her genetic disorder is carried along in your breeding line of guppies.

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Posted by Andria H:
I was so freaked out by just seeing and witnessing my precious guppies eat their own young.. It somewhat changed how I think about my fish haha. This was kind of a cool story to read though. glad someone added some value on this topic without hiding behind the pretty frosting. My mom thought there was maybe something wrong with only my fish but it turns out that is not the case. Keeping them well fed with good food really helps too.