[JDM]

37 gallon freshwater
78F
7.4 pH
ammonia 0
nitrite 0
Nitrate 0-5ppm
dGH and dKH high teens
Tank is almost 11 weeks old.
Lots of plants
No medication, treatments or chemicals of any kind other than weekly fertilization with flourish comp.
Weekly water changes in the 30% range... missed this weekend.

We have an emerald brochis that is struggling right now. I netted it and looked closely with a magnifying glass but can see absolutely no signs of any discolouration, gill issues, fin problems, parasites that might be visible, no spots nothing. I assume some swim bladder problem as the fish cannot stay upright, but tries. It is now somewhat "bent". at first I thought it was from curving while trying to get upright but it isn't the case, the bend must be a symptom.

The odd time it gets upright and swims for a moment and, other than the bend, it looks fine.

I skipped through all of the diseases here and the only one that doesn't have some other obvious visible symptom is the bladder.

Small backstory.

We bought 8 of these cats originally (47 days ago), got 9 (freebie), one with damaged dorsal fine. Two weeks, almost to the day, that fish passed. OK, it happens with new fish and I think the store guy sort of half expected it. I inspected the fish afterwards and found nothing obvious other than the fin problem and the resulting colour drain due to having been dead for at least a few hours... but I honestly don't think that alone could be a real fatal problem. I saw no symptoms in this case, one day 9 catfish, next day 8 catfish.

I bought two more almost three weeks ago (19 days). They were of the same original batch so I cannot tell them apart but I may assume that this is one of the new recruits... two weeks and a few days after bringing them home. Perhaps some delayed shock of introduction? I float the bags, add tank water gradually (over a minimum of 30 minutes... closer to an hour) then net them into the tank... I don't like putting store water in my tank if I can help it.

Jeff.

 

[Byron]

I can't identify the problem, but I will say that the gill and pectoral fin area on the fish in the photo is not good. Now, if the fish is fighting some issue, this may be expected. Or it may be the issue or part of it. Or it just may be the photo, as colours do get distorted.

Can you check the others to see if this shows on them? Don't net them, just try to see them as they swim in the tank. Netting too will make whatever this is worse, as it adds stress.

You are right never to add water from the bag into the tank. All sorts of pathogens plus ammonia are in the bag and you don't want any of that. Then there is the deadly toxin that these fish can excrete from the gill/pectoral spine area that can be fatal to themselves as well as all other fish.

Did these latest go into a quarantine tank?

 

[JDM]

That red must have been a reflection as it is not apparent otherwise. The others look normal.

No quarantine.

Anything else that can come up like this and still have the fish look, otherwise, healthy still?

Jeff.

 

[Byron]

That red must have been a reflection as it is not apparent otherwise. The others look normal.

No quarantine.

Anything else that can come up like this and still have the fish look, otherwise, healthy still?

Jeff.

There are so many possibilities. Internal damage done from capture and transport. Something genetic. Internal protozoan. Stress.

Quarantine is important. If this was due to a protozoan, that can be dealt with in QT.

 

[JDM]

It actually didn't take long to come up with quite a list of possible causes. I'm still leaning toward something in the transfer process from store to home. If I knew for certain that this was one of the new ones, particularly seeing as the ones at the store were from the same initial batch and I had probably the same thing around the same time as the other confirmed injured fish.

Well see what tomorrow brings. It's not like there is any treatment for this without knowing exactly what the true cause might be.

Jeff.

 

[Byron]

It actually didn't take long to come up with quite a list of possible causes. I'm still leaning toward something in the transfer process from store to home. If I knew for certain that this was one of the new ones, particularly seeing as the ones at the store were from the same initial batch and I had probably the same thing around the same time as the other confirmed injured fish.

Well see what tomorrow brings. It's not like there is any treatment for this without knowing exactly what the true cause might be.

Jeff.

Yes (to your last sentence). Also, if the store is reliable, see if they have had losses.

Corydoras do not like being disturbed in any way. Considering how sensitive they are, it is quite a wonder that so many get to our tanks.

 

[JDM]

Good idea. Seeing as it was a batch of 50 they brought in and they haven't had them before, recently, losses should stand out.

The little guy didn't make to the night last night, let alone through the night.

I'm watching the rest closer to see if anything appears out of the ordinary. I thought one might have been a little lethargic this morning... but that's hard to pin anything on. They are usually quite active and any that are not I would expect would stand out, but maybe not if it's not looked for specifically.

Jeff.

 

[JDM]

A followup.

I lost one more catfish, slightly different symptoms, same result. This time more colour loss and a little popeye going on and less or no spine curving. I'm going to assume some sort of infection. Everyone else seems lively and normal, good colours.

A thought.

Most of my plants are stem or tall. I have one corner behind a vertical piece of driftwood where the cats most often congregate. I put a couple of new crypts in yesterday and I already see the cats coming out under them a bit more than they would into the open area and are SLIGHTLY less skittish (although this is a subjective observation and deserves more observation).

I started with 9, lost one due to supposed injury during catching him at the store two weeks later, damaged fins were visible. I added two more to bring them up to ten and have since lost two... between two and three weeks later. I suspect, but cannot be certain, that they were the two new additions. The store claims no unusual losses and that the ones that they still have seem healthy and strong... I don't honestly know if they would own up to losses or not so this is suspect.

Given that my tank bottom is 12" x 30" and they are almost always in the rear right corner, perhaps the layout is limiting their numbers somehow? 8 seems to be the baseline.

I don't mind experimenting with plants, add some, toss some, thrive or not no big deal... I hesitate to do the same with fish. I was going to add more lower smaller plants to provide more cover on the bottom and see how the current 8 respond and will consider adding two more again if they respond well.

Any thoughts on whether I may be anywhere near correct in any of those assumptions?

Jeff.

 

[Byron]

Most of my plants are stem or tall. I have one corner behind a vertical piece of driftwood where the cats most often congregate. I put a couple of new crypts in yesterday and I already see the cats coming out under them a bit more than they would into the open area and are SLIGHTLY less skittish (although this is a subjective observation and deserves more observation).

Given that my tank bottom is 12" x 30" and they are almost always in the rear right corner, perhaps the layout is limiting their numbers somehow? 8 seems to be the baseline.

I don't mind experimenting with plants, add some, toss some, thrive or not no big deal... I hesitate to do the same with fish. I was going to add more lower smaller plants to provide more cover on the bottom and see how the current 8 respond and will consider adding two more again if they respond well.

Any thoughts on whether I may be anywhere near correct in any of those assumptions?

Partly. If you read the habitat data in the profile, it mentions "Occurs in slow-flowing streams and sluggish waters with dense vegetation." All the Corydoradinae are skittish by nature. They like a "roof" above them, which is why lots of chunks of bogwood with crevices, overhangs, etc. work so well. Knowing they have hiding spots usually brings them out more, though they still take time to settle in to a new environment. I have had corys that took weeks to get used to their environment when I just moved them from one tank to another.

You want some open area, for feeding. But add a few more chunks of Malaysian Driftwood [not sure how many you have, I am assuming only one] and this may settle them more.

Byron.

 

[1077]

I might consider running an air stone or sponge filter at night when plant's are using oxygen.
Oxygen is often lower at the bottom of the tank than at the surface where exchange takes place and maybe the cory's are finding it in short supply of an evening.
Might also cease with blood worm's if they are being offered.More folk's are feeding these less now day's due to their poor nutritonal value (mostly water/moisture by content).
Might mix some ant parasite med's with fish food and garlic extract to form a paste.Then freeze the paste and offer only this food for three or four day's in small chunk's). May want to fast the fish for a couple day's before trying the medicated food.(so they are hungry)
Would lower temp slowly from 78 to 75 degree's F which will slow down any possible bacterial pathogen from spreading, as well as help with oxygen level's.
Might consider twice weekly water changes for a few week's as well.
Would rinse all new plant's under tapwater before placing them in the tank to hopefully remove any insecticides that some large grow facilities use on emersed plant's to prevent insect's from eating up the leaves on their plant's.
I'm no expert,,just offering some thing's I might try.
Hope you lose no more fishes.