I can't tell which pathogen or problem is affecting these corydoras, and I don't know how to proceed. Any help or advice is appreciated

[rebe]

I've been quarantining these corys for about a month now, and I still have concerns about them. I'm listing the details and attaching photos in the hopes that some of you may have some ideas or insights into what is going on. I'm not sure if I should try raising the temperature to 30C for two weeks, or to try worming them. Maybe they're overweight?
This issue is only with the corys in the tank and not the rasboras, but since it's an issue with most if not all of the corydoras, I don't think that it's a growth or tumour.
I'm grateful for your help in threads about various issues I've had with this group of fish so far!

Problems:

• Bloated, swollen abdomen
• Flicking/rolling into the substrate

Background:

• 105L quarantine tank (75x35x40cm)
• Sand, plants, filter, heater (25C), airstone
• 10 corydoras (originally 14) purchased 29 days ago (March 3rd)
• QT tank mates: 9 hengels rasboras and a few bladder snails
• 9 degrees GH, 0ppm Ammonia and Nitrite, 7ppm Nitrate (tap water level)
• Fed six days a week, close to 50% frozen and live food diet.
  • (Bug bites and Oase Organix, frozen bloodworm, daphnia, mysis and artemia, and live BBS)
• Weekly water changes of 50-60%

Relevant notes:

• I finished removing the last of the salt from the tank a few days ago, after treating with salt for saprolegnia fungus. I used the higher dose of salt that Colin recommended (2 heaped tablespoons of salt per 20 litres.)
• After fasting them for two days, I fed boiled and de-shelled peas in case the issue was digestive like constipation. No improvement after 12+ hours
• When I got these fish, some of their barbels were quite badly eroded but they seem much better now. Some of them have completely normal barbels.

 

[AdoraBelle Dearheart]

Husbandry and water all sounds brilliant, as I expected when I saw it was you! Definitely keep them and the other fish in QT until you're completely happy that they're good.

Man, panda cories seem pretty weak lately... I think they might be being mass produced, I know I had no luck when I tried them despite trying hard...

Some of the females are looking pretty chunky, and you're conditioning them well with that feeding.... have you noticed any spawning behaviour? Chasing each other around?

I honestly don't know, but I'd probably worm them, to be on the safe side, if they're store bought, possibly mass farmed, then it wouldn't hurt to worm them, and might resolve it. It's clearly not water quality producing the flicking, and while I don't like throwing meds at fish without being sure what's wrong, it's hard to spot worms in cories compared to say, livebearers, and is the flicking occasional, or pretty frequent?

 

[Lcc86]

I had a similar issue with my cories not too long back and went through a course of worming to be on the safe side, it seems to have done the trick although I did lose the ones I was most concerned about. Mine didn't have sunken bellies but had barb/fin damage and were flicking/rolling so symptoms sound similar to yours. Hope you can get to the bottom of it!

 

[Colin_T]

flicking and rubbing on things is normally external protozoan infections.
they do have some excess mucous that could be water quality related.

the fat stomachs could be food or worms. tumours take a few months to grow. cysts can appear in a week or two.

deworm them and see how they look after that.
section 3 of the following link has info on deworming fish.

What to do if your fish has Stringy White Poop.

Fish do a stringy white poop for several reasons. 1) Internal Bacterial Infections causes the fish to stop eating, swell up like a balloon, breath heavily at the surface or near a filter outlet, do stringy white poop, and die within 24-48 hours of showing these symptoms. This cannot normally be...

www.fishforums.net

 

[rebe]

Husbandry and water all sounds brilliant, as I expected when I saw it was you! Definitely keep them and the other fish in QT until you're completely happy that they're good.

Wow, thank you Adora! That made me so happy to hear, it really means a lot!!
And yes, I'm planning to keep them all in the QT until the problem and concern is over

Some of the females are looking pretty chunky, and you're conditioning them well with that feeding.... have you noticed any spawning behaviour? Chasing each other around?

I mean maybe it could be eggs causing the swelling, but it seems like the swelling is far up the abdomen and close to the head. I thought because of that the swelling couldn't be eggs. You could very well be right, although that would mean I have mostly females in order for so many of the group to be swollen. I'll have another look at them, and see if I can spot any fish without the swelling, and if they are more slender and smaller like I've read males should be.

is the flicking occasional, or pretty frequent?

TBH I don't have a reference for what would make the behaviour occasional vs frequent, so when I sit down to inspect the cories I'll see how many times I see the flicking within a certain time period.

 

[rebe]

I had a similar issue with my cories not too long back and went through a course of worming to be on the safe side, it seems to have done the trick although I did lose the ones I was most concerned about. Mine didn't have sunken bellies but had barb/fin damage and were flicking/rolling so symptoms sound similar to yours. Hope you can get to the bottom of it!

Thank you, so far treating them for worms seems like the best course of action. I'm not glad that you also went through this experience, but I am glad that I'm not alone and have other peoples experiences to compare mine to

 

[rebe]

the fat stomachs could be food or worms.

deworm them and see how they look after that.
section 3 of the following link has info on deworming fish.

Thanks Colin! I think I will go ahead and start a deworming treatment, I hope that will help and alleviate some of their discomfort at least!

 

[AdoraBelle Dearheart]

Thanks Colin! I think I will go ahead and start a deworming treatment, I hope that will help and alleviate some of their discomfort at least!

Have a look at the thread Colin linked to make sure you buy the right meds. I used the eSHa products to treat both round and flatworms, and that did eradicate the camallanus worms my tanks were infected with, and since my livebearers had a high chance of carrying both round and flatworms, I opted to do a course of the eSHa NDEX, and a course of the eSHa GDEX, and that cleared up my worm problem!

Good news is that they also didn't harm my plants, shrimp or snails. Cheap generic wormers aren't always effective, you want levimisole as an active ingredient, and praziquel for the other type of worms, which are the active ingredients in the two eSHa meds above! I only suggest them because I know they work from personal experience, and what meds are available for fish varies hugely by country, but I'm pretty sure you'll be able to access the same meds as here.

I wouldn't be surprised though if you do find eggs all over the tank at some point! They're large enough and mature enough to breed, I see males in the pics, and some nice chunky females (could be a combo of both a worm burden, and carrying eggs making them look more round, but sometimes female fish can get pretty chunky looking when preparing to spawn! I was worried about one of my bronzes in QT, her abdomen got so round, that it looked like she'd swallowed a cory sized beach ball, and made her sit funny on the sand. Sure enough, found eggs everywhere, just as I was preparing to move them from their month QT tank to the main tank, and I was totally unprepared! Fun though, and female's body shape did go back to normal. But it's typical for females to look much chunkier and more girthy than the males. Sometimes a view from the top down can help you see the difference.

While you're looking for/waiting for worming meds (and I'd still worm, potential spawning or not) you could try some cooler water changes to encourage spawning, see what happens! Just do a reasonably sized water change- 30-40%, and have it just a 2-3 degrees cooler than the normal tank temp. Replicates their spawning in the rainy season in the wild, and can help prompt them to spawn. No need to worry about raising fry this time either, only if you want to, but it still might be worth doing a couple of cooler water changes - early in the am when sunlight is first hitting the tank room is ideal, if I remember rightly, but not an essential element!

What have you got to lose?

 

[AdoraBelle Dearheart]

@DoubleDutch! So glad to spot your name with this cory thing, you know a great deal more than most about keeping them, love to hear what you think of these pandas? I'm wondering if they're a little pale? But never kept Pandas (for long, anyway, tried a small group early on in my hobby and was gutted to lose them all quickly. So I'm not so familiar with them beyond seeing them in stores and pics.

 

[rebe]

Have a look at the thread Colin linked to make sure you buy the right meds. I used the eSHa products to treat both round and flatworms, and that did eradicate the camallanus worms my tanks were infected with, and since my livebearers had a high chance of carrying both round and flatworms, I opted to do a course of the eSHa NDEX, and a course of the eSHa GDEX, and that cleared up my worm problem!

My amazing local friend @Flowerfairy13 just gave me some of her eSHa NDX, with the active ingredient levamisoli hydrochloridum! So how does this sound to you?

1. Properly read Colin's article while performing a 40% cold water change
2. Start treatment with eSHa NDX

 

[AdoraBelle Dearheart]

My amazing local friend @Flowerfairy13 just gave me some of her eSHa NDX, with the active ingredient levamisoli hydrochloridum! So how does this sound to you?

1. Properly read Colin's article while performing a 40% cold water change
2. Start treatment with eSHa NDX

Hmm, maybe 30-35% for the first one, less drastic, can always do small and frequent, along with the usual weekly water changes. Or just make the new water during your normal water changes a degree or two cooler than the tank temp. I think the action of the fresh water pouring/trickling in also helps get them feeling frisky..! Ahem.

Lemme grab my bottles and check the instructions again. It was a few years ago now, and I forget the order I did it in. I remember it was a lot of work and hassle, since I was doing all my tanks plus bleaching equipment in between, since I hadn't learned my lesson about QT yet! But it was worth it, and if your QT methods are stricter than mine were, like no shared equipment with your main tanks, which they almost certainly are! You might be fine just worming the QT tank.

Have to double check the boxes, but if I remember rightly, the NDEX asked for two treatments, two weeks apart? Then the GDEX was like, medicating for a few days then water changing out. So if I remember rightly, I did the first course of NDEX, water changed it out and ran carbon in the filter to clear out any remaining meds, then did the GDEX course during the gap between the two courses of NDEX.

Could likely space them out though if that works better for you. I was just at a bad point when I discovered what was causing my guppies to die, so was really aggressive with treating them, and had the time to do all the needed water changes and steralising equipment etc.

 

[rebe]

Hmm, maybe 30-35% for the first one, less drastic, can always do small and frequent, along with the usual weekly water changes.

Currently draining water! I'll do 30ish% then

 

[Colin_T]

When deworming fish, just treat the tank once a week for 4 weeks so you kill any baby worms that hatch after the treatments.

Do a 75% water change and gravel clean the substrate 24-48 hours after treatment. Clean the filter too. This removes worms and eggs from the tank.

 

[rebe]

Lemme grab my bottles and check the instructions again.

just treat the tank once a week for 4 weeks

So just to check, I dose by the package instructions then do 75% water change and gravel clean the substrate 24-48 hours after treatment. Repeat this four times over four weeks?

To be completely honest with you guys, I'm feeling overwhelmed at the prospect of 75% water changes on all three tanks (the 280L in particular.) I use the same pump and hose for water changes, does that guarantee worms in all the tanks when there is only swelling in the corydoras in the QT? Rationally I know that 75% isn't much bigger than the 50% I do each week anyways. Do you think I could get away with only treating the QT with the cories when they're the only swollen ones and without being sure that it's even the issue?


These are the eSHa NDX instructions:

 

[AdoraBelle Dearheart]

Okay, I read the instructions for both, and that was how I did it anyway, and it's easier than I remember it being, somehow! I think 'cos I had four or five tanks then, so doing all those extra water changes and setting alarms for when to repeat the meds was a bit of a hassle. Totally worth it though!

Yep, NDEX is a 24 hour treatment, then you water change it out (adding carbon to the filter can help remove the med from the water, but it's not essential if you prefer to just do some large water changes to dilute it out. NDEX says you can repeat a fortnight later, so I set an alarm for that. During that two week gap, after clean water and a couple of days resting and recovering time for fish, I did the three day GDEX course, water changed that out and ran carbon again, then did that second course of NDEX.

Instructions for NDEX do say you can do a third treatment if needed for persistent issues, but my fish were much better after the first courses, and I only did the second course of NDEX to be sure any worms had gone!