Sick pregnant platy?

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Aquarium Advice Newbie
Feb 7, 2023
Hello I made an account on here just so I can ask for advice on this because my internet searches have gotten me nowhere.

On the 28th of december of 2022 I bought 4 platies, one of which was pregnant already. They settled into the tank just fine, eating and acting healthy. Now of course the pregnant platy over time got bigger and bigger and everyday I checked on her to see if she had given birth yet. But no such luck. The longer this went on, the more concerned I grew..I looked up what the normal pregnancy term for a platy was and found out it was about 28 to 30 days. Well she passed that milestone a few weeks ago and still no babies and she looks increasingly uncomfortable. She is very bloated but her scales still lay flat and her anus (?) is looking very swolen. She has a dark pink spot near her vent that I think is the mass of babies, i think i can even see a few eyes but i feel like it doesnt look like it should. She also often has trouble passing poop which i figured was because the babies were pressing on her guts so I have tried two times to fast the all the fish for 24 hours. Doesn't really seem to help her. She also has been hanging around the floating plants more often lately and also has been rubbing herself against plants and decorations and having spurts of erractic swimming lately. The other fish and shrimp are acting fine and also are not harassing her. Here are some photos I took of her yesterday:


Water parameters:
Temperature: 24 degrees celsius
Ph: ~8
Gh: between 7 and 14
KH:~10? (I use a test strip so it's hard to precisely say)
Ammonia: Dont have a test for that but the other fish seem fine?
Nitrates: 10 ppm
Nitrite: 0 ppm

Tank size: 125 Liters, 81cm x 36 cm x 48 cm
Tank set up time: I first set it up on 22 november 2022 and I added the first fish (5 corydoras and one juvenile bristlenose pleco) on the 16th of december. Haven't had any nitrite spikes in all the time ive had this tank.

Filter: Juwel Bioflow M

7 panda corydoras
10 Lambchop rasboras
1 bristlenose pleco (~6 cm at the moment? not fully grown yet)
4 Platy fish (1 male and 3 females)
6 amano shrimp
~15 cherry shrimp
5 assasin snails
a huge amount of pest snails

Last waterchange was actually yesterday and it was a 10 percent waterchange. I didn't have any nitrites or anything but I thought it might help her feel better. I typically do them every 2-3 weeks tho i probably could go longer because my water parameters are stable

I have recently added an airstone to the opposite corner of the filter to hopefully add more oxygen to the tank in case that was the problem.

I feed my fish Oase Organix color in granulate form, it used to be duplarin colour S but I felt like it didn't have very high quality ingredients so I stopped feeding that like 3 weeks ago? I feed my corys tropical supervit tablets b for bottom feeders and Oase Organix Snack sticks which i mention because my platys like to nibble on their food also. My pleco gets half an organix veggievore algea wafer from time to time but its mostly the snails that eat that. I also fed them bloodworms yesterday after fasting them on sunday to see if some high protein food would help and i think i saw her briefly bleeding a bit from her anus that night??? I check on my fish after the lights go off with a flashlight from time to time so thats how i noticed. The other fish didnt go after her tho.

So yeah I think thats about all the info I have..I hope you guys can help me :(
Hi and welcome to the forum :)

She could be having issues giving birth or just a long labour. It can be longer than a month if the water is cooler or she might hold onto them longer if she is stressed.

She could have intestinal worms and most common livebearers from Asia do have intestinal worms, (see below for treating fish for worms).

Don't reduce feeding or fast gravid (pregnant) fish. They need all the nutrients they can get.

Don't move her either. Just give her lots of plants to hide in and keep any annoying fish away from her.

You should do a decent size (50-75%) water change every week, or at least every 2 weeks. The water might not have nitrates but fish live in a soup of microscopic organisms that continue to build up in numbers. If you don't do regular water changes, the fish can become weaker and get sick from the pathogens in the water.


Intestinal Worms like tapeworm and threadworms cause the fish to lose weight, continue eating and swimming normally, and do a stringy white poop. Fish can do this for months and not be too badly affected. In some cases, fish with a bad worm infestation will actually gain weight and get fat and look like a pregnant guppy. This is due to the huge number of worms inside the fish.

Livebearers like guppies, mollies, swordtails & platies are regularly infected with gill flukes and intestinal worms. If the fish are eating well but do a stringy white poop, then worms is the most likely cause.

You can use Praziquantel to treat tapeworm and gill flukes. And use Levamisole to treat thread/ round worms. If you can't find these medications, look for Flubendazole, which treats both lots of worms.

In the UK look for:
eSHa gdex contains praziquantel that treats tapeworm and gill flukes.
eSHa-ndx contains levamisole and treats thread/ round worms.
NT Labs Anti-fluke and Wormer contains flubendazole.
Kusuri wormer plus (contains flubendazole) - sold mainly for discus, comes as a powder which is quite hard to dose in smaller tanks
Sera nematol (contains emamectin)

Remove carbon from filters before treatment and increase aeration/ surface turbulence to maximise oxygen levels in the water.

You treat the fish once a week for 4 weeks. The first treatment will kill any worms in the fish. The second, third and forth treatments kill any baby worms that hatch from eggs inside the fish's digestive tract.

Treat every fish tank in the house at the same time to prevent cross contamination.

You do a 75% water change and complete gravel clean 24-48 hours after treatment. Clean the filter 24 hours after treatment too.

Do not use the 2 medications together. If you want to treat both medications in a short space of time, use Praziquantel on day one. Do a 75% water change and gravel clean the substrate on day 2 & 3. Treat the tank with Levamisole on day 4 and do a 75% water change and gravel clean on day 5, 6 & 7 and then start with Praziquantel again on day 8.

The water changes will remove most of the medication so you don't overdose the fish the next time you treat them. The gravel cleaning will suck out any worms and eggs that have been expelled by the fish. Repeating the treatment for 3-4 doses at weekly intervals will kill any worms that hatch from eggs. At the end of the treatment you will have healthier fish.
Thanks for the advice! I ordered some HS Aqua dewormer tablets, they should arrive tomorrow. I only hope that they will be shrimp safe as I don't have a second tank to transfer the shrimp to and also they would be very hard to catch. As for waterchanges I have heard that it's best to leave established tanks alone as much as possible but I suppose I could do bigger water changes when I do them. maybe not 75 percent tho, i feel like that would stress out the fish unnesesarily (how do you even spell that)
Any idea what the ingredients are in the HS Aqua dewormer tablets?
You only need Levamisole for thread worms, which are the most common worms found in fish.

Praziquantel to treat tapeworm

Flubendazole does all worms but I think it also kills snails and shrimp.


You need to do water changes regularly even if the water tests are good. There are lots of things in water that we can't test for and they need to be removed as well.

You do water changes for a number of reasons.
1) to reduce nutrients like ammonia, nitrite & nitrate.
2) to dilute disease organisms in the water.
3) to keep the pH, KH and GH stable.
4) to dilute nitric acid produced by fish food and waste breaking down.
5) to dilute stress chemicals (pheromones/ allomones) released by the fish.
6) to dilute un-used plant fertiliser so you don't overdose the fish when you add more.
7) to remove fish waste and other rotting organic matter.

Fish live in a soup of microscopic organisms including bacteria, fungus, viruses, protozoans, worms, flukes and various other things that make your skin crawl. Doing a big water change and gravel cleaning the substrate on a regular basis will dilute these organisms and reduce their numbers in the water, thus making it a safer and healthier environment for the fish.

If you do a 25% water change each week you leave behind 75% of the bad stuff in the water.
If you do a 50% water change each week you leave behind 50% of the bad stuff in the water.
If you do a 75% water change each week you leave behind 25% of the bad stuff in the water.

Imagine living in your house with no windows, doors, toilet, bathroom or anything. You eat and poop in the environment and have no clean air. Eventually you end up living in your own filth, which would probably be made worse by you throwing up due to the smell. You would get sick very quickly and probably die unless someone came to clean up regularly and open the place up to let in fresh air.

Fish live in their own waste. Their tank and filter is full of fish poop. The water they breath is filtered through fish poop. Cleaning filters, gravel and doing big regular water changes, removes a lot of this poop and harmful micro-organisms, and makes the environment cleaner and healthier for the fish.

Whilst you might not have ammonia, nitrite or nitrate problems, the number of micro-organisms in your tank will be growing exponentially due to lack of water changes and this will eventually cause problems to the fish. At the very least, water changes should be done to dilute disease organisms.
Sadly it appears the HS aqua dewormer I ordered isnt shrimp safe so i went to my local fishstore to ask about shrimpsafe dewormer. He said he didnt have any but maybe esha2000 general cure will help. I think that's actually a good thing to try first since I dont actually know for sure if it is worms. I did a 50 percent waterchange and cleaned the filter when i got home (found a lot of snail poop under a piece of driftwood so i took care of that), fished out my assasin snails since they can't handle this medication very well (they are in a temporary hold plastic tank that already has a bunch of pest snails. since the medication period is 3 days and the pest snails have been in there fine like a week I hope they will be alright) and just now i added the normal first day dose for the medication. I am also going to order the esha medications you mentioned online just to be safe in the future. I do have medication that i cant use now but oh well you learn through making mistakes. Maybe I can trade it or give it to someone local who doesnt have shrimp or snails and can use it. we will see what happens. I also had a look at my other female platy that has been acting weird and it appears her anal region is also injured but I can't see it well. Hopefully this general cure will take care of any infections
The esha 2000 general cure contains copper and that will kill shrimp and snails.

It also contains ethacridine lactate, which is used for abortions so I'm not sure how well the baby fish will do.

It contains methyl orange, which is a pH indicator. I can only assume they added that so the chemical appears as a colour in the water.

It contains proflavine, which is a disinfectant.

Personally I would be careful using any of this in a tank with gravid fish or baby fish.
Weird that their website says that its safe for shrimp then..its late now and tank lights are off so I will see what it looks like in the morning..Can't do another waterchange now. Hope I wont have any dead shrimp.
Update! Just checked my tank with a flashlight and while the shrimp seem fine so far, I can see lil thin worms poking out of my pregnant platy now! So she does have worms! I have already ordered the esha dewormer (both ndx and gdx) which should be getting here on saturday. can't take pictures of the worms now because its too dark but man, what evil lil buggers attacking my platies like that.

I really hope I am still on time to save them..The orange platy that seems the most affected has a pretty big injury on her anal region
Copper will kill any invertebrates in an aquarium. This includes things like shrimp, snails, starfish, corals, sea anemones, etc.

If she has hair like worms sticking out her butt, they are thread worms and you only need to treat for that. If you can cancel the other medication (used for tapeworm) it will save you some money.
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