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Do Pregnant Guppies Stay At The Top? Is It Normal Behavior?

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Raising a pregnant guppy is pretty exciting. However, it also comes with a little bit of stress. I remember how confused I felt when I saw that my pregnant guppy was consistently swimming at the top of the tank. Fortunately, as time passed, I gained some experience in this field.

Pregnant guppies tend to stay at the top of the tank when in labor. Swimming at the top allows them to deliver their fry in a peaceful environment, with as little harassment as possible. However, pregnant guppies may also swim at the top when they are looking for food or potentially sick.

As we move forward, I will elaborate on why pregnant guppies tend to swim at the top. I will also mention in which cases it may indicate that the fish is sick. Then, I’ll discuss what you, as an aquarist, should do when your pregnant guppy refuses to leave the upper sections.

Still curious? Feel free to check my complete guide on pregnant guppy fish. There, I discussed how to care for pregnant guppies, how long they remain pregnant, how to identify signs of pregnancy, and a lot more.

Do Pregnant Guppies Stay At The Top?

If you have male and female guppies in the same tank, the male fish will inseminate its female counterpart within days. Once conception occurs, the pregnant guppy’s behavior will change, but in ways that make sense.

For instance, pregnant fish will either hide from their tankmates or lash out at any creature that invades their breeding space. 

But what about swimming at the top? Should pregnant guppies swim at the top? Surprisingly, this behavior is usually expected. 

However, the reasons compel a pregnant guppy to swim at the top vary. They include:

1. Your Guppy Is In Labor

A pregnant livebearer will manifest certain unmistakable signs, including a darkening and expanding gravid spot, swollen belly, loss of appetite, and more. 

The creatures have a gestation period of 21 to 31 days, but that range is wide. You cannot determine a guppy’s due date using the gestation period. Fortunately, guppies will manifest specific symptoms shortly before they go into labor.

The most prominent are a black gravid spot, box shape, and the visibility of the offspring’s eyes through the guppy’s belly. One other notable sign is the guppy’s swimming behavior. 

The guppy will hover at the top when it is going to give birth. This is as good a time as any to move the female to a breeding tank if you have one. The guppy will most likely give birth near the top.

But that doesn’t mean she will stay at the top. The guppy may drop a few babies, swim around for a while, and then drop some more fry. Depending on the creature’s temperament, it may eat the fry it just dropped. 

Though, the birthing process is so stressful for some guppies that they don’t have the strength to hunt for or eat their offspring so soon after giving birth to them.

2. The Guppy Is Trying To Hide

When a fish doesn’t feel safe in the aquarium, it will hide behind the plants and decorations. If the tank doesn’t have enough plants and decorations, the fish will hang out at the bottom or near the top. You also see this in overcrowded tanks.

Pregnant guppies are more vulnerable than non-pregnant guppies. Unfortunately, males are enthusiastic breeders. They start by chasing the females around the tank before extending the gonopodium and using it to inject sperm into the female’s anal vent.[1]

A healthy female can withstand the attention of a male guppy. If you don’t have enough females, the male fish may harass the few females in the aquarium to death. 

But for the most part, a healthy female will survive a male’s sexual advances. Yet, the same cannot be said for a pregnant female. Male fish will continue to harass the females despite their pregnancies. 

A pregnant female that doesn’t have hiding places will hang out at the bottom or the top in the hopes of avoiding the attention of the male guppy. 

3. Your Pregnant Guppy Is Tired

Pregnant fish prefer to stay out of sight partly because of how weak and lethargic they become as the pregnancy progresses. During the final stages of the pregnancy, a pregnant guppy may stop moving altogether.

People expect these creatures to hover quietly and silently behind plants, pots, or filters until they give birth. But the guppy may choose to lie still at the bottom or hover at the top. 

Sick guppies are equally lethargic. They don’t have the strength to swim. Therefore, if they find a comfortable spot near the top, they may become dormant.

Keep an eye out for signs of diseases and infections. For instance, ich produces white spots that cover the fish’s skin. Velvet produces gold-colored dots. 

Fin rot destroys the guppy’s fins and tail. A fish with columnaris will develop patches of fungus around the mouth. Dropsy causes bloating.[2]

If you have any doubts regarding the guppy’s condition, talk to a vet. They can determine whether the guppy’s lethargy came from the pregnancy or diseases and infections. 

If the pregnancy is responsible for the lethargy, you can leave the guppy alone. But if it has an illness, the vet can recommend an appropriate treatment. Diseases can lead to abortions and premature labor.

4. Your Aquarium Features Floating Plants

Do you have floating plants like hornwort in the aquarium? Pregnant guppies will hide behind any barrier that makes them feel safe. If they feel safe while hanging around the plants at the top, they will swim at the top.

You can expect the same behavior if you have filters near the surface. Pregnant guppies have a reputation for hanging around or hiding behind filters. They are more likely to drop fry while at the top if they have hiding places in those sections of the tank.

5. The Guppy Is Merely Sleeping

Guppies sleep, even though they don’t have eyelids. Like other aquarium fish, they become less active during these rest periods. This allows the creatures to stand out because they are usually very active.

They typically slumber at night when you switch the lights off. At that point, they will either hover in place, moving slowly and sluggishly or lie motionless at the bottom.[3] 

While people expect the creatures to sleep on the substrate, they can also float at the top. It depends on the guppy’s preference. Either way, pregnant guppies require sleep. 

If they only hover at the top when the lights go off, and if they are motionless during this period, you can dismiss their behavior as a sign of sleep.

6. Your Guppy Is Looking For Food

Pregnant guppies will eventually lose their appetite. But that doesn’t mean they will stop eating altogether. You have to continue adding food just in case the fish decides to eat.

A pregnant guppy may frequent the surface because it wants to eat the food you just sprinkled at the top, or the creature tells you to feed it.

Healthy, non-pregnant guppies do the same thing. They cannot verbally communicate their need for food to you. But they know that the food always comes from the top, so they will let you know that they want food by hovering at the surface.[4]

What Should I Do With Pregnant Guppies Swimming At The Top?

Generally, you shouldn’t do anything. If you determined that your guppy is pregnant, and it keeps floating at the top, it is probably going to give birth. At this point, the fish is highly vulnerable, so you shouldn’t make any drastic changes.

I also suggest that you avoid breeding boxes at this stage. However, you may consider placing an aquarium divider. This will allow the fry to swim to the other side of the tank without being eaten.

You may also measure the water parameters to ensure they are suitable for pregnant guppies:[5]

  • Temperature: 77-79° F (25-26° C) 
  • pH: 7.0-7.6 
  • Hardness: 7-12dGH 
  • Ammonia & nitrites: 0 ppm 
  • Nitrates: <20 ppm

To measure the pH, nitrates, nitrites, and ammonia, I personally use the API Water Test Kit (link to Amazon). This bundle is highly accurate and easy to use. It also lasts for eight hundred measures, making it highly cost-effective.

If your tank requires a water change, do it gently. Conduct several small water changes instead of a single large one. Make sure that you spread them across the entire week. Drastic changes will stress your pregnant guppy more than the inadequate water parameters.

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Conclusions

You shouldn’t panic if your pregnant guppy is swimming at the top. If you can’t find any signs of diseases or infections, it is likely that your pregnant guppy feels more secure up there. The behavior should stop after they give birth. 

Generally, I suggest that you avoid making any drastic changes at this point. You may consider placing an aquarium divider to ensure the fry won’t be eaten. You can also test the water parameters. However, if they are wrong, make small and gradual water changes.

References

  1. https://fishtankadvisor.com/pregnant-guppy/
  2. https://guppyexpert.com/guppy-diseases-parasites-remedies/
  3. https://jaljeev.com/do-guppies-sleep/
  4. https://www.itsanimal.com/what-causes-my-guppies-to-swim-at-the-top-of-the-tank-9-reasons/
  5. https://fishtankadvisor.com/pregnant-guppy/