Female Guppy Behavior Before Giving Birth

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As an aquarist, understanding a female guppy’s typical behavior before giving birth is crucial. Normally, like all fish, guppies are active, social, and have consistent eating and swimming habits. They’ll actively interact with their tank mates, swim comfortably around the tank, and show a healthy appetite. Changes in these behaviors often signal a pregnant guppy about to give birth, which we’ll explore further in this article.

What Changes Can You Observe in the Anatomy of a Pregnant Guppy?

When a female guppy is pregnant, several noticeable anatomical changes occur. As the eggs develop inside her, her belly will expand and become rounder. The color can also fluctuate, tending towards a darker shade. Perhaps the most recognizable sign is the appearance of a gravid spot – a darkened area near the guppy’s anal vent, indicative of pregnancy.

As she nears delivery, this spot may become more pronounced. These changes are largely due to the physical accommodation and protection of the developing embryos. Therefore, understanding these changes is vital to monitor the guppy’s health and predict the delivery time.

What is the Gravid Spot and Why is it Important?

The gravid spot is a unique physical trait observable in pregnant female guppies. It’s a darkly pigmented area located near the guppy’s anal vent, often becoming darker and more prominent as the guppy nears delivery.

This spot is essentially the developing embryos within the guppy’s body, visible due to the female’s semi-transparent skin. It’s an essential factor in determining if your female guppy is pregnant and how close she may be to birthing.

The darkening of the gravid spot, along with a change in its size, can be critical clues that your guppy is nearing delivery, thus enabling appropriate preparations.


How does the physical appearance of a female guppy change as she nears delivery?

As a female guppy approaches delivery, several changes can occur in her physical appearance. One of the most noticeable changes is in her stomach, which becomes increasingly larger and more rounded.

Typically, the female’s belly acquires a dark, almost black coloration due to the developed embryos inside her, often referred to as the ‘gravid spot’. In some cases, an examination from the side can even reveal the eyes of the fry within the mother’s transparent tummy. Furthermore, the pregnant guppy may also exhibit a ‘boxy’ appearance, where her body becomes square.


What Behavioral Changes Can You Expect in Pregnant Guppies?

As female guppies approach the birthing phase, they exhibit numerous behavioral shifts, reflecting their physiological alterations and gearing towards a smooth birthing process. These changes typically involve modifications in their social interactions, movements, dietary habits, and breathing patterns.

Additionally, pregnant guppies strongly tend to isolate themselves from the rest of the group, showcasing obvious restlessness and preference for calm, secluded spaces. These behaviors represent an instinctual drive to protect their offspring amidst the dense and diverse ecology of an aquarium.

How Do Social Interactions and Isolation Patterns Shift?

Guppies in general are highly social creatures. They typically enjoy the company of their peers, swimming and interacting within their shoal. However, as a female guppy approaches her birthing period, you may observe a stark shift in this natural social tendency.

The upcoming delivery triggers behavioral changes that compel the female guppy to isolate herself from the rest of the community. This is a defense mechanism intended to protect her and her offspring from potential threats in the vulnerable period of delivery. Isolation allows the female guppy to find a quiet, secure location to give birth and safeguard her fry.

How Do Movement and Swimming Patterns Alter During Pregnancy?

The standard swimming behaviors of guppies generally present smooth, unhurried movements. However, during pregnancy, the swimming patterns of a female guppy may change significantly. You may notice erratic swimming actions or excessive darting around the tank, generally due to discomfort caused by the growing embryos.

Female guppies in the late stages of pregnancy often show noticeable restlessness, frequently resulting from the need to find an appropriate safe spot for delivery. The presence of larger embryos also contributes to this restful behavior, as they limit the internal space the female guppy used to navigate freely before pregnancy.

How Do Dietary Habits Change in Pregnant Guppies?

Guppies are omnivorous under normal conditions, showing keen interest on a wide menu, encompassing plant matter, invertebrates, and even fish flakes. However, the dietary habits of pregnant guppies shift as they approach the birthing period. You might notice an unexpected indifference to food, sometimes entirely refusing to eat before giving birth.

This unusual behavior stems from the internal pressure of growing fry reducing her stomach’s capacity. Maintaining excellent water quality during this phase is essential. Poor quality or contaminated water can stress the pregnant guppy, exacerbate her dietary issues, and potentially harm both the mother and unborn fry.

What Breathing and Physical Signs Indicate Impending Birth?

As the birth of a guppy approaches, there are distinct signs in her breathing and physical movement that you should watch out for. Typically, a healthy guppy’s breathing rate is around 60 breaths per minute. A pregnant guppy nearing birth may exhibit an increased breathing rate, which serves as an exciting sign indicating that birth is imminent.

Furthermore, physical contractions, evident in the undulating movement of the guppy’s body, can often be seen too. These contractions suggest that she is trying to push out the fry – a key sign that the birthing process is underway. 

Why Do Pregnant Guppies Isolate and How Can You Facilitate This?

Isolation in pregnant guppies is triggered by a natural survival instinct when birth approaches. The guppy chooses a safe and quiet spot, usually in densely planted corners of the tank, to avoid predators and stressful stimuli while giving birth.

As an aquarist, facilitating this act of isolation involves providing an environment that caters to this instinctive need for safety. Introduce sufficient hiding spots like plants or breeding caves into your tank. Moreover, maintaining a peaceful aquarium community with non-aggressive species and monitoring water quality contributes to a safe environment for your pregnant guppy to give birth.

How Should You Prepare for the Birth of Guppy Fry?

As your female guppy approaches birth, careful planning is needed to ensure the survival and well-being of the guppy fry. There are specific steps you should take as your pregnant guppy manifests the behaviors and physical changes indicating impending birth.

These preparation steps not only focus on facilitating the birthing process for the pregnant guppy but also prioritize the protection of the newborn fry in the aquarium. From setting up a separate birthing tank to strategizing ways to shield the fry from potential threats, each stage requires thoughtful consideration and action.

Why Consider Setting up a Separate Birthing Tank?

Creating a separate birthing tank is an important aspect of successful guppy breeding. The main advantage lies in its ability to provide a safe space for the mother guppy to give birth without stress or interference. It also offers immediate protection for the newborn fry from potential threats, including predation by adult guppies in the main tank.

An ideal birthing tank should include a heater, a gentle filter, appropriate lighting, and several hiding spots for newborns. It’s essential to maintain clean water and stable temperature, simulating the conditions in their natural habitat. Considering these aspects can greatly improve the survival rate of guppy fry and optimize the health of the pregnant female.

How Can You Protect Newborn Fry in the Aquarium?

After the guppy has given birth, your primary concern becomes the security of the newborn fry from natural predators within the tank. Adult guppies, along with other larger fish varieties, can potentially prey on the fry. Therefore, providing a sanctuary becomes an aquarist’s key responsibility.

You can safeguard the fry by separating them, using a tank divider or introducing them into a separate tank. Providing plenty of hiding places using plants and small caves is another effective measure. Feeding larger fish adequately might also help to discourage them from preying on tiny fry. Observing these mandates ensures the successful upbringing of newborn fry in the aquarium.

How Should You Feed and Care for Newborn Fry?

Once the female guppy fills her birthing duties, your attention should shift towards caring for the newborn fry. Survival of younger ones relies heavily on your caregiving strategies. Fry are extremely small and fragile, requiring a specific feeding pattern.

Initially, live foods like Infusoria or artificial foods such as high-quality fry food are ideal. Remember to feed the fry multiple times in a day but in small portions to avoid overfeeding.

You also need to maintain optimal water conditions. Frequent water changes, keeping a check on the temperature, and ensuring a stress-free environment are key. Furthermore, providing adequate hiding spots, employing fry-trap, or using a separate fry tank can protect the young ones from potential predators.

Updated: October 19, 2023
Questions & Answers
  1. Can i just keep the baby guppies in the tank with other fish ( i have five guppies including the mother, a glass fish and one tetris) when they are born or is that too risky??

    1. avatar

      Hey Avy, you can keep the babies in the mains tank, but the chances are high to get eaten. If you don’t want to risk it, I recommend using a breeding box.

      1. Ginger Green

        Hi I have a guppy that has seemed to be huge for at least 2 weeks now I think she may have had 1 to 2 fry that got eaten and then stopped giving birth but that was over a week ago but she still looks pregnant everytime I move her to a breeder box or smaller tank she lays on bottom and I never see any results is this natural

        1. avatar

          If a female guppy can’t give birth to all fry within 2-3 days, she will die. In this case, I think that she already gave birth to all fry, and you are stressing her without reason.
          Usually, after female guppies give birth, they will get smaller in size, but right after that they will start developing the new fry. Sometimes there is no noticeable change in their size after giving birth.
          I think that all the fry were eaten. Wait a couple more weeks and she will deliver again for sure.

  2. Hi our female guppy is in active labor but it looks like her insides are coming out. Only 1 fish so far and she keeps flipping upside down is this normal?

    1. avatar

      When guppies turn upside down, it is a sign of a problem. This is not normal at all.
      Sometimes female guppies have complications at giving birth (just like humans). In fact one female can die to high stress experienced during labor. This is sad, but it happens.

  3. I have kept the female guppy in a separate bowl already because I cannot understand when she’s due. She’s quite round now. If I keep her there for a few days will it be stressful for her? The bowl is quite big.

    1. avatar

      If the bowl is big enough, it will be ok. I usually do the same when don’t have enough aquariums for new fry. I put the females in 1 gallon containers for 2-3 days with an air stone.

  4. Jan Marie

    Thank you very much very informative and helpful. I love my guppies

  5. Help! My other guppies are following and seem to be attacking my female that had recently gave birth. They think she is a food dispenser. What can I do to help her other than keep her in a separate container?

    1. avatar

      A breeding box could be a good solution for the female guppy while giving birth. This way you could save the fry and also keep her separated without setting up a new tank. I don’t think that the other guppies are attacking here, however the males probably are chasing her, because they want to breed. This can be really stressful for the female, and often can result in the death of the female guppy.

  6. Hi I have my female guppy in breeding box and the female is changing up and down the bottom side to side kind off nose down. Is this sign off Labor

    1. avatar

      She is probably stressed because of the tight space. It not necessary a sign that she is in labor.

  7. Hello! I have a female that is very big but I don’t see that her gravid spot is very dark.. could it be there is something else going on? She seems to be spending a lot of time either at the top or hiding behind some of the plants in the tank. She has been bigger than our other female since the day we got her and i believe she dropped some fry about 5 weeks ago but she never really slimed back down. I did send an email on the contact page with a photo. The top of her back looks to have a slight curve in it. Thanks for any help

    1. avatar

      Hey Jenn. I’ve got your email. From the picture you sent the female guppy look fine to me.
      Though, it is a common thing in female guppies to have difficulties while giving birth. It is also common for female guppies to die after giving birth. If she dropped only 5 fry few days ago, maybe the other fry are stuck in here stomach. I don’t see any sign of disease on the picture you sent, so I think it could be a complication while giving birth. Hope she will release the rest of the fry and will survive.

  8. This article is really well done. Thank you!

    A question: at what age can I put the fry in a tank with substrate?

    1. avatar

      Hey Kelly! You can put the newborn guppy fry in a tank with substrate right after they are born. I recommend using a sand or fine gravel substrate for fry, which can be vacuumed easily.
      Most guppy breeders keep guppy fry in a bare bottom tank, because it is easier to clean, though I like to keep a sand substrate with my guppies.

  9. Hi, is it alright if I have 3 pregnant guppies in a tank but with no coverage yet. they seem to be really still too unlike the other fishes. Is it normal?

    1. avatar

      You can keep guppies without coverage, however the fry will not survive. Your female guppies may be ready to give birth, that is why they are staying still.

  10. stanley Rolle

    I see the shape on the fish so i take it she is in labour. Last Time my fish had fry, i first saw many then only one and no bodies floating. Now I know what happened. The female is staying very still most times and so I will relocate her to another tank. Hope it cause no stress. This article has been most helpful. I am grateful

  11. Shankar

    My guppy have bend back Spain is this guppy will give birth…please tell me about this.

    1. avatar

      Guppies with bent back can also give birth to fry. Though the chances to give birth to deformed spine fry is very high. I would not breed guppies with such genetic problems.

  12. Jess Parkyn

    My guppy has been pregnant for over a month and is getting followed by 2 fishes is this causing stress and does that mean she won’t give birth until relaxed

    1. avatar

      Stress can be dangerous for pregnant female guppy, especially if she is due. You can separate here in a bowl or a breeding box to reduce stress.

  13. My female dropped only 3 fry in the breeder box then stopped. She is still squared with a gravid spot. I put her back in the main tank after 24 hours as there was no further progression. The fry are still in the breeder box and doing well.
    There are dividers in the breeder box, so I can put her back in if she will continue to drop. It’s been 3 days now and nothing.
    She has been pooping non stop though, is this a sign to put her back? Or do you think she’s absorbing the rest of the fry?

    1. avatar

      When female guppies are young, they do indeed give birth to only a few fry. This is totally normal. Their body might also look the same after giving birth.
      Though, if an older female drops only 3 fry, and she looks like never gave birth, then it might be a problem. This can also be deadly, because there might be some complications. Try to not put here through more stress. Just leave here alone and hope she will drop the rest of the fry too. You can add more live plants into your tank to give the fry some hiding space.

  14. hi I just got my guppy two weeks ago and now are pregnant, I was wondering when I could sale them. I already have way too many.

    1. avatar

      You can ask your local pet store if they are willing to buy your fish, or you can try to sell them online – maybe this will be much faster.

  15. oh and do yo know if I put my guppy back in after she give birth, will the other guppies chase her and stress her out.

    1. avatar

      Female guppies are chased by males all the time, especially after they give birth, because the males can “smell” the hormones the female releases. It can be stressful, but if you keep a 1 to 3 male to female ratio, all females should be fine.

    1. avatar

      Keeping multiple pregnant guppies in the same breeding box depends on the size of the breeding box and type. Usually most breeding boxes are made for one fish only.
      Also consider the fact they might eat each-other’s fry.

    1. avatar

      This breeding box is small, though I think it is enough to keep a female guppy fish for couple of hours in it. I wouldn’t keep a guppy in this box for more than a day. It can be stressful to be enclosed in such a tiny space for too long.

      1. I have one female guppy in a tank with an angel fish, a beta fish, a Bala shark and a loach. There was an endler in the tank until August. I found three fry in December and after moving them out I found an older endler fry. I moved it out too as the loach wanted to eat it. She is pregnant again. What are the chances the fry will survive when the father is an endler and how long can she keep becoming pregnant when she has had no males in the tank with her since August?

        1. avatar

          If you cross breed endler guppies with fancy guppies, there is a really high chance that the fry will survive, although their genetics will change. You can’t really know what traits the offspring will have, but the chances of surviving are really good.
          A female guppy can be pregnant for months after mating. So she can give birth to fry 5-6 times after mating with a male.

  16. Danielle

    My female guppy fish keeps attacking the males. She has a lump on her belly but no gravid spot. Should I move her to another bowl

    1. avatar

      Is she only attacking the males when you approach the tank or all the time? Maybe she is just becomes territorial when you are feeding them, so she can get more food. Usually female guppies do not attack the males. Male guppies can fight between each other, but females do not fight usually.

  17. Laura Hutchinson

    I have 4 females all ready to give birth any day now but only one birthing box is there anything else I can use so there not all in 9ne and stressed

    1. avatar

      If you don’t have enough live plants, you can make a guppy breeding mop from acrylic yarn (buy from Amazon). There are lots of tutorials online on how you can make these spawning mops. These are great if you are running a bigger breeding operation, because the breeding mops are reusable.

  18. I’ve separated my pregnant guppy into the isolation box in the tank and from the other two male guppies in my tank. She is just laying under the plant and doesn’t move around much while the two males are like standing guard right next to the box at the top. None of them are swimming around. They have been doing this for a couple of days. Is this normal?

    1. avatar

      This is normal. Please consider, that one female to 2 males ratio is not the best. You should have 3 females to one male ratio. Probably your female is stressed out by the two males.

  19. Abel Ayres

    My female guppy is sitting in the top of the tank and it looks like she has a hole in her gravid spot no fry and she is following the male i am worried because she was pregnant but the male died and I got a new male do you think this caused her stress she has not had any fry but has been pregnant for weeks help!(you should call you self a guppspert in stead of guppy expert.

    1. avatar

      It takes usually 4 weeks for a female guppy, to give birth again. Sometimes the gestation period can take up to 30-35 days, so just be patient. She might be stressed, because the male is stress here out. You should keep a 3 females to 1 male ration, in order to avoid stress in female guppies.

  20. Margaret Petersen

    How can I tell when my mama guppy is done birthing her babies? I don’t want her to start eating them. She’s in a birthing net thingy with a divider with slots that I thought the babies would drop down through but, the little stinkers are staying in the top portion with mama! There are about 15 of them. She still looks very full. My first guppy babies.

    1. avatar

      It is not easy to tell when a female guppy finished giving birth. 15 fry sound good, but there should be more coming, especially if the female looks still big. Once her belly gets flat, it is done and you can remove her from the breeding box.

    1. avatar

      This is a normal behavior among guppies. This is part of their breeding ritual. They wont hurt each other, don’t worry about it.

  21. Hi, i have two pregnant female guppies and this is my first time breeding them. I am not sure how far along they are since I’ve e picked them up a week ago. I was wondering when would be the best time to start putting the separator in the breeding box for the fry so that they don’t get eaten.

    1. avatar

      It is really hard to tell when a female will give birth, when you don’t know the mating date or the prior date of giving birth.
      I suggest that you watch the female behavior. When the female gets inactive, sits at the bottom of the tank or hides between plants or other decoration, most likely she will drop the fry very soon. Also watch the belly of the female. When it becomes more like a square, she is ready to give birth.

  22. Courtney

    I got two male guppies a week ago. It is a new aquarium and I know that can throw things off. I don’t see the black spot on the back of the belly but he is laying on the bottom of the tank with a big appetite. Wondering if he may be a she and it’s pregnant.

    1. avatar

      Adult male and female guppies can be easily distinguished from each other, but there breeds, in which female guppies are also very colored.
      Probably your guppy is laying at the bottom, because the water parameters are not right. In a new tank, which is not cycled yet, there could be ammonia spikes, which will affect your guppies.
      Ammonia poisoning can make a guppy lay at the bottom of the tank. Do a 20% water change and monitor your fish. Hope, all gets back to normal.

      1. Courtney

        So I did this and added an air pump. He is still laying at the bottom and gulping for air. The other guppy is loving the bubbles 😍

  23. Katy Moreno

    Can I wait to put my little Prego into the breeder box until I see her start popping out fry? Or will that stress her too much?

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