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Is It OK To Let Guppies Eat Their Fry?

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If you are growing guppies, you probably see that the parents have no mercy. They will eat their fry without hesitating. As this happened to me, I felt uncomfortable, as I wasn’t sure if it was ethical or reasonable. Fortunately, over the years, I gained some experience in this field.

It is considered OK to let guppies eat their fry, as this is what also happens in nature. Doing so won’t cause any harm to the adult fish or the water chemistry. Some people even consider guppy fry as feeder fish, which are grown for the purpose of feeding other fish.

As we move forward, I will elaborate on whether it is okay to let guppies eat their fry. Then, I’ll share some excellent tips on how to get rid of unwanted guppy fry without letting the parents eat them alive. In some cases, you’ll even be able to profit from it.

Still curious? Feel free to check my complete guide on guppy fry. There, I discussed how to care for guppy fry, what they eat, how often to feed them, their growth stages, and much more.

Is It OK To Let Guppies Eat Their Fry?

Well, the answer to this question depends on who you ask. This sounds like a simple question, but it has several dimensions that aquarists much consider before they reach a conclusion. They include the following:

1. It Also Happens In Nature

Some people argue that aquarists should allow adult guppies to eat their babies because the same thing happens in nature. And that is true; filial cannibalism is prevalent in nature.[1]

Adult fish will eat their offspring for no apparent reason. That includes live fry and eggs. Guppies are not unique in that regard. Some people argue that female guppies are genetically predisposed not to eat their fry.[2]

But if that were true, aquarists wouldn’t bother separating female guppies from their offspring. Many aquarists keep them separated for 6 to 8 weeks so that the mother won’t eat her fry.

Female guppies may spare their young ones shortly after giving birth to them. But that will change in the coming hours and days once the female recovers from the stress of labor. 

Some people blame this on stress. Stressful conditions in an aquarium can drive any creature to attack smaller, weaker fish, even if it gave birth to those fish. Others have attributed filial cannibalism to starvation.

But even if the tank has plenty of food, the guppies may respond to a perceived scarcity of resources by eating the fry to store energy. On occasion, the goal is to eliminate genetically weak offspring.[3] 

But the reason doesn’t matter. Ultimately, guppies in the wild will eat their fry in the absence of all these factors. Therefore, permitting the creatures to replicate this behavior in a tank makes sense.

2. You Will Control The Population

Guppies are beautiful creatures. However, some aquarists are hesitant to rear them because they breed too quickly. They can easily overwhelm your aquarium with babies.

You can interrupt their mating habits by keeping the males and females in separate tanks. You can also discourage breeding by limiting food supplies. Research has also shown that factors that threaten their survival can influence the breeding patterns of guppies. 

For instance, guppies that share their home with predators will devote a large chunk of their body weight to the development of their offspring.[4]

Even more fascinating are female guppies that extend their gestation periods in tanks with a limited food supply.[5] Therefore, you can prevent breeding in guppy tanks if you make a deliberate effort.

However, the methods mentioned above are time-consuming. If you barely have the time to feed your guppies, the notion of separating the genders and limiting the food supply won’t appeal to you.

You are better off introducing fish that eat guppy fry. They will control the guppy population on your behalf. Bettas are one example. They will appreciate the nutritional value of your guppy fry.[6]

If you have adult guppies in the tank, you don’t have to add bettas. The best way to increase your guppy population is to isolate pregnant females. Once they give birth, move the females back to the tank. 

Allow the babies to mature safely in a spawning container. But if you don’t want the guppy population to skyrocket, you can leave the mother in the main tank. This way, only 15% are expected to survive.

Once the female guppy gives birth, she will share the guppy fry with the other adult fish. The presence of predators in the main tank may also prevent the female guppy from giving birth in the first place. She may choose to reabsorb the fry.

3. Some People Treat Them As Feeder Fish

Have you heard of feeder fish? These are fish that aquarists rear for the express purpose of feeding other fish. The feeder fish are weaker and smaller than the fish they will feed. 

Feeder fish are attractive for several reasons:

  • First of all, feeder fish are live foods, and live foods are more nutritious than flakes and pellets, primarily if you feed the feeder fish well.
  • Secondly, feeder fish simplify mealtimes. The fish don’t require your presence to feed. They will help themselves to the feeder fish in the tank.
  • Feeder fish are the perfect alternative to automatic feeders. If you usually forget to feed your fish, feeder fish will solve this problem because the fish feed themselves. 

If you travel frequently, you can leave your fish alone, knowing that they have plenty of food in the water. They won’t starve.

Feeder fish are cost-effective, especially if you have species like Platies, Mollies, Ameca Splendens, Zebra Danios, and, most importantly, Guppies that reproduce rapidly. 

If you have a large tank with a sizable population of sexually mature fish, the babies they produce will feed the aquarium indefinitely.

You can rear fish with the intention of feeding them to other fish. But this process is time-consuming. It also requires significant resources, depending on the number of fish you want to feed.

If you can barely maintain one tank, a second feeder tank will stretch your patience to the breaking point. But you don’t have to bother with feeder tanks if you have guppies.

Just let them breed. Rather than removing the babies, allow the other fish to eat them, including the guppies. This is the cheaper option.

Is It Ethical To Let Adult Guppies Eat Their Fry?

The ethical considerations concern some aquarists. Is it right to allow one living creature to eat another living creature? Well, it depends. Some aquarists condemn this practice because it is cruel, while others disagree.

Proponents argue that allowing adult guppies to eat their babies is no different from feeding the adult guppies other small creatures such as bloodworms, earthworms, and shrimp.

Flakes and pellets are just as problematic. The companies that manufacture them know that fish require protein. Therefore, they must have killed animals at some point to secure the ingredients they needed to give flakes the protein content your fish need.[7]

Additionally, proponents will tell you that death for small fish like guppy fry is quick, no different from the experience of a worm when you kill it shortly before adding the creature’s remains to the water for a guppy to consume.

But opponents of this practice have a different perspective. First of all, no one can definitively prove that guppy fry don’t suffer when an adult fish eats them. 

Do the babies die immediately, or are they more likely to suffocate inside the adult’s stomach? What if the adult guppy bites pieces out of the baby instead of swallowing the fry whole? 

Many aquarists have suggested that fish don’t feel pain because they don’t have pain receptor nerve cells. 

However, recent scientific discoveries have disproven that hypothesis. Therefore, to these individuals, it is unacceptable to feed guppy fry to their adult counterparts.

What Else Can I Do With Unwanted Guppy Fry?

Letting guppies eat their fry isn’t the only way to get rid of them, as I have already shown here. In short, there are less crucial ways you can take. For example, you can sell the fry for profit.

Depending on the species, some stores will pay up to $5 per fry. You can also give the fry away for free. Many aquarists will be glad to get them. Try posting it on social media.

Either way, letting guppies eat their fry won’t do any harm. It doesn’t have any effect on the water chemistry or the parents’ health. This is how nature behaves, and like in most cases, there is nothing we need to do about it.

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Conclusions

You shouldn’t feel guilty if your guppies eat their fry. That also happens in nature. Like most other fish, guppies will eat whatever fits in their mouths, including their babies. But if you feel uncomfortable with it, there are some things you can do.

For example, you can sell the fry. Many aquarists take advantage of the breeding capabilities of guppies to make a profit. You can also give the fry for free to other fish keepers. You may even give the parents themselves and start a new generation of guppies.

References

  1. https://www.sciencedaily.com/releases/2016/02/160210111907.htm
  2. https://waterworldcraze.com/do-guppies-eat-baby-guppies/
  3. https://www.aquariumnexus.com/guppies-eat-their-fry/
  4. https://www.jstor.org/stable/2407978
  5. https://www.brown.edu/news/2017-10-11/guppies
  6. https://www.ultimatebettas.com/betta-fish-eat-guppy-fry/
  7. http://wetwebmedia.com/FWSubWebIndex/fdgfdrartneale.htm