# Anyone know what’s wrong with my Sterbai Cory?



## MissInked (Sep 8, 2021)

A few days ago I noticed 1 of my 4 Sterbai Corydora’s looked really fat and was kinda swimming near the bottom a little weird, like it’s having a bit of trouble swimming cuz it’s so chunky. It’s been a few days and it hasn’t gotten any better (or any worse) so I’m no longer thinking maybe it’s egg bound and it seems to still be eating I think (all 4 are pretty skittish). I had just done a water change 2 days before I notice this and my tank has been consistently stable for over a year after switching to a soil substrate which caused an ammonia spike. I am having a bit of an issue with algae so maybe that could have something to do with it??

Water parameters are:
PH: 6.8
Am: 0
No2: 0
No3: 5.0ppm
KH: 53.7
GH: 143.2
CA: 100.

If anyone has an idea of what’s wrong and what if anything I can do to fix it would be greatly appreciated, it’s not pineconing so I’m thinking maybe constipated? I’ve never had a constipated fish before so not really sure if that’s what it is. .


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## EDGE (Aug 24, 2010)

female with eggs + full stomach. Corydoras usually don't get constipated. They can expel extra food via the back end from the stomach. I fed mine 3 to 4 times a day at one point for conditioning but was causing problem for pleco. Currently at 2 times a day with less food so the pleco don't over eat.



https://www.tropicalaquarium.co.za/threads/fat-cory-catfish.32427/


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## MissInked (Sep 8, 2021)

So it’s been 5 days, I did a 30% water change on New Years Day with water 2 degrees cooler which in the past has caused my Cory’s to spawn but in this case it didn’t and my Cory still looks fat and uncomfortable. . Maybe she’s not full of eggs? She should’ve laid them by now no?


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## EDGE (Aug 24, 2010)

Try asking on a catfish forum. been 20 years since I had sterbai and bred them. I had mine in 80 to 82f water and did daily water change. sterbai is one that like a bit warmer water.

Do you have a lot of water current? They get sluggish if there isn't enough current. I use a 530 gph wavemaker in a 20g high to keep them active.


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## MissInked (Sep 8, 2021)

Current is low, I have a sponge filter in the back corner of each side of the tank, both are for up to 70 Gallons but I have the air pump on a lower setting as to not create too many large bubbles.

I have at least 2 males in the tank but I’m pretty sure she’s the only female out of the 4 I have. 3/4 have always been together, I bought 4 of them 2 years ago and they had spawned on 2 occasions when I did a water change with cooler water but I switched my tank from a gravel substrate to a soil one with a 2” cap of gravel and sand because I wanted more live plants which caused a crazy ammonia spike (I didn’t know better at the time) and killed the female I had so I bought another single Sterbai hoping it was a female because I was pretty sure the other 3 I had were male and looks like I was right at picking the largest one they had. They haven’t spawned since the substrate change but she was still a lot smaller than the other 3 until recently as I’ve had her for a year.

PH is already on the low side at 6.8 so I don’t really want to lower it anymore, it’s usually around 7.2-7.4 since I’ve had the tank going for 3 years now.


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## EDGE (Aug 24, 2010)

There are different triggers for different Corydoras species. Some don't need triggers and others can be quite finicky.

pH drop, cooler water. atmospheric pressure from rain storm, etc. As an example, You don't want the parameter of the pH to be lower in the tank, but the water change pH to be lower than the tank water as a trigger and then let the pH go back up - kind of like how we do cooler water change as a trigger, pH can do the same.

when there is a rainstorm in the forest, blackwater get flushed out from the peaty river / bog and raise in pH momentarily in that area and white water can be mixed with blackwater to lower pH from the blackwater run off.

There is an article online for breeding Corydoras pulcher. Probably the only one in documentation as they do not spawn easily. He did a water change with 6.5 pH and his tank parameter is at 7.2. they spawn right on the bottom of the tank where the sand were blown away by the current of the filter. - I can't read German. I typed in the google translator to see what the article say.

Just saying, sometime cories take more than cool water change to trigger into spawning.

Do you remember what the pH was in the setup when they spawn? and the pH from the water change? Was the water change with straight tap water? GVRD water had a pH increase sometime in Summer of 2021 when they added more cabonate buffering to reduce pipe corrosion.

Was the Sterbai in a different tank? Just a bit confused because the tank has been running for 3 years, but got the sterbai 2 years ago. Swap the tank from gravel to soil and then they died? The tank has been running for a year with soil? Is the current system at 6.8 pH because of the soil or acid buffer?


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## MissInked (Sep 8, 2021)

I remembered today that I triggered them to spawn by doing a water change with cooler water and pouring it in through a cup with holes in the bottom to simulate rain as I read somewhere that this had worked for someone else’s Sterbai Cory’s as it makes them think it’s the rainy season which is when they generally spawn. I don’t know what the PH of the water was that I did the change with last time they spawned, I just used tap water with water conditioner and added Nutrafin Cycle like I usually do. I’ve only had the soil substrate for a year but I had the tank going for 2 years before that with gravel and sand substrate which killed one of my four Sterbai Cory’s and was pretty sure it was my only female too. The Sterbai spawned in this same tank just when it had the different substrate.


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## EDGE (Aug 24, 2010)

The female is normal with the chunky body. Some of my males look similar without the width of the female

Male









Female (for reference, the PVC pipe in the photo is 1.5"; 1.9" Outer Diameter)









If the Cories are getting fed twice a day, I would be more worry about flat / sunken stomach than a round stomach. Either they are not eating or there is some parasite / worms sucking the nutrients from them.


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