Tigrinus catfish w/ infection

[.C.J.]

I just noticed that my 24” tigrinus has something on both sides of its gills. It looks like an infection of some sort or a flesh eating bacteria cause i notice that the soft part of the gills looks like its being eaten away or rotting. It doesnt look like its been bullied by any of the tankmates as the lesion looks like its coming from inside the gills.

i dont have any idea what might cause this problem as ive kept it for a bit over 4 years with the tank parameters sitting consistently at
0 ammonia
0 nitrite
40-80 nitrate
idk if its because of me feeding the tank more frequently which caused because theres these slime like things on my pumps and wavemakers and also on one corner of the tank where the tigrinus usually stays. Im not sure though because this is the first time that, that appeared in my tank. even back then when there was 8 17-20” asian arowanas in my tank it has never happened.

the tank is 350 gal 6x4x2 btw. Hope to have a better understanding regarding whats happening to my tig. Thanks so much!

 

[Fishman Dave]

Not necessarily caused by feeding the tank more frequently but in my opinion it is all related. The grey slime is most usually from uneaten food breaking down in the tank which also will increase the nitrates. The nitrates are already high and both things together are a source for irritation and disease to take hold in the fish. I am not surprised that your ammonia and nitrite are zero on one reading but would also not be surprised to find that at points after feeding both were spiking and causing more irritation.
You mention wavemakers but do not say what filtration you have on this large impressive tank volume.
Also please advise what other tank mates there are.
Anything similar seen ( possibly not as the tig may be the most sussceptable/fragile).

 

[..puSkar..]

High nitrates are generally the primary cause of gill infections imo .

 

[kno4te]

Keep nitrates down and below 20ppm. If still not better then consider a antibiotic.

 

[.C.J.]

Not necessarily caused by feeding the tank more frequently but in my opinion it is all related. The grey slime is most usually from uneaten food breaking down in the tank which also will increase the nitrates. The nitrates are already high and both things together are a source for irritation and disease to take hold in the fish. I am not surprised that your ammonia and nitrite are zero on one reading but would also not be surprised to find that at points after feeding both were spiking and causing more irritation.
You mention wavemakers but do not say what filtration you have on this large impressive tank volume.
Also please advise what other tank mates there are.
Anything similar seen ( possibly not as the tig may be the most sussceptable/fragile).

The tank is being filtered by a trickle filter and an overhead sump that is connected to a 8500lph pump. Tankmates are, 19” batik arowana, 16” nami green arowana, 20” silver arowana, 2 mekong giant catfish which are 12”’ and 9”, 8” red hook and 8” black bar red hook. I’ll try feeding them less for now and do partial water changes every other day. Hope it helps. The tigrinus isnt acting any different other than it not eating, which is probably because of the gill problem. But other than that it’s active and swimming around the tank when the lights are off. It’s also not gasping for air, in which i read that is a symptom of gill infections.

 

[.C.J.]

High nitrates are generally the primary cause of gill infections imo .

Thanks for your input. I’ll do partial water changes every other day to see if anything improves

 

[.C.J.]

Keep nitrates down and below 20ppm. If still not better then consider a antibiotic.

Keeping my nitrates below 20 is something that ive never achieved before. Because of the load of the tank. But i’ll still try, water changes every other day should help and keeping the feeding at minimum. Thank you

 

[aroijuana]

This is why tigs are one of the most sensitive catfish. They start to develop this and open wounds behind all fins when the nitrates rise to higher than normal numbers & oxygen starts to deplete. You'll notice this develops alot faster without tons of water movement in the tank. I've went threw this two separate times with my tig while on vacation. I used kanaplex, small amount of salt, & very clean water too clear it up. Be shure to clean your sponges/filter floss & keep the water pristine.

 

[thebiggerthebetter]

I've never seen it on our tigs.

I generally don't believe tigs to be a sensitive, touchy or fragile fish from our experience with 12 tigs from baby up to 5-7 years old, but may be wrong about older tigs.

It looks like a bacterial infection. The most likely reason is the tig is stressed. High nitrates is the only red flag from what's given. This can be the source of stress, especially because nitrates is not an absolute test, as many other anions interfere with the test, like the ubiquitous chloride. The 40-80 ppm nitrate could be okay if this was an absolute number but in reality the number can easily be 2x, 3x, 5x or even 10x higher. The acute toxicity of nitrate begins around 1000 ppm, if memory serves. If your 40-80 ppm is in reality 400-800 ppm, that can be lethal in not too long a run.

If not nitrates, you will have to troubleshoot other sources of stress, like wrong water hardness and salinity, pH, unstable pH, etc. I can paste a complete questionnaire to help in asking yourself questions.

...

I don't like the slime comment either. If the slime appearance coincided with the tig losing appetite and this inflammation appearing, it's more than a valid reason to figure out what this slime is and where and why it appeared.

Set up automated WC, what they call drip, if WCs are laborious.

 

[.C.J.]

This is why tigs are one of the most sensitive catfish. They start to develop this and open wounds behind all fins when the nitrates rise to higher than normal numbers & oxygen starts to deplete. You'll notice this develops alot faster without tons of water movement in the tank. I've went threw this two separate times with my tig while on vacation. I used kanaplex, small amount of salt, & very clean water too clear it up. Be shure to clean your sponges/filter floss & keep the water pristine.

Im suspecting the cause might be because of the chums in the water that is caused by the batik when im feeding it. It recently developed this habit of chewing its food too much before swallowing it which causes a lot of floating fish chunks on the water as compared to before when it swallowed its food instantly. Probably thats what caused the slime build up because theres too much organics in the water. Plus, i didnt clean the sponges this week when i did my weekly water change routine.