Who is mauling my angelfish or is it a disease ?

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Caveat....I have yet to own Angels......but....

BN's are known to attach to a slabsided fish on occasions where the chance presents itself, such as a resting Angel, to enjoy the slimecoat. They do it at night when the slabside fish is static/resting. The removal of slimecoat can trigger infection and will inevitably leave open sores which other fish can then nibble at. BN's are very similar to the Chinese Algae Eater in that if the opportunity arises they will latch onto a dozing fish after dark. The more times that the BN latches onto the fish, the weaker it will become and the BN learns that its available without much resistance.

Not every BN will do it but they are known to be opportunistic in that regard. I would not dismiss the BN as the culprit so easily.

The wounds on the Angel are fairly identical in size and shape/depth for a sniper BN slimecoat attack. When the fish loses slimecoat in that way it does leave angry sores which can encourage other fish to tuck into the now open raw flesh.

Definitely do not dismiss the BN. The L204 is purely veg orientated whereas the BN does have carnivorous traits. Dismiss my theory if wished but my money is on the BN doing sniper slimecoat removals at night.
My honest guess was either a disease of some sort or the BN - the wounds are not deep. My question is the wound directly due to the BN (if it is a BN); or due to infection? I don't see any obvious signs of infection but I'm not sure what i would see if there is an infection. I have a particularly large plain male BN that never comes to the front during feeding time and that would be the one I suspect but is there any way i can 'prove' that is the cause of the damage ?
 
Have you ever seen angels do this sort of damage to each other with the ones you have ?
Angel fish can be jerks, worse than any other Cichlid I have kept before. I had a group of 7, they were a cantankerous bunch, if I could keep a single pair I think that would be ok, but a group, nope. I finally gave up and got rid of them. It is too stressful to try to keep them from ganging up on one or shredding another. They are beautiful fish but dang.

A Bristlenose would not make those wounds. Let alone be able to suck/adhere to the side of the fish long enough to do so. BN's don't concern themselves with tank mates unless they are guarding fry, even then it is a tail slap.
 
My honest guess was either a disease of some sort of the BN - the wounds are not deep. My question is the wound directly due to the BN (if it is a BN); or due to infection? I don't see any obvious signs of infection but I'm not sure what i would see if there is an infection. I have a particularly large plain male BN that never comes to the front during feeding time and that would be the one I suspect but is there any way i can 'prove' that is the cause of the damage ?
I don't believe this damage is through disease since the wounds are too identical. They are, however, virtually the same as a CAE type sniper wound and something that a decent sized BN will do.

I would take the Angel out of the aquarium, do daily water changes and keep the water as clean as you can. Use salt and not off the shelf medications and let the fish heal in peace.

Watch for similar damage to the other Angels once the damaged one is out of the way......however, I suspect being the 5th Angel and thus alone, it is the easiest fish to attack since the pairs will defend each other.

People assume that a BN is a peaceful beast but they, like the CAE, can and will take advantage of slabsided fish when they are resting at night. Watch a BN, they are not slow moving fish by any means and they are very partial to slimecoat when adults.
 
I don't believe this damage is through disease since the wounds are too identical. They are, however, virtually the same as a CAE type sniper wound and something that a decent sized BN will do.

I would take the Angel out of the aquarium, do daily water changes and keep the water as clean as you can. Use salt and not off the shelf medications and let the fish heal in peace.

Watch for similar damage to the other Angels once the damaged one is out of the way......however, I suspect being the 5th Angel and thus alone, it is the easiest fish to attack since the pairs will defend each other.

People assume that a BN is a peaceful beast but they, like the CAE, can and will take advantage of slabsided fish when they are resting at night. Watch a BN, they are not slow moving fish by any means and they are very partial to slimecoat when adults.
All the angels but the largest male has similar wounds at this point. It started with one fish but this has been on going for 4 months. I have no place to put such a large fish - i live in a condo and cannot add another aquarium due to HOA rules. For QT and medicine I use 5 gallon pails but these fishes are too large for such. I raised them from frys and they are a bit larger than store purchased fishes. Because of the tank size I'm unable to catch this BN - he hangs out in the very back and i did not leave enough room behind the tank for a stool - worse he is evasive. When he was younger I tried to remove him but after a few weeks of trying i gave up. The pain of a larger tank. When i move next year I will learn from these mistakes (and have room in the basement for isolation aquariums).
 
What are you feeding the BN?

I understand you have the L204 in the aquarium aswell, is there a chance that the L204 is feeding and the BN isn't getting enough food?

Do you feed in one spot or do you put food at opposite ends of the aquarium so that they can both eat without squabbling?

The BN usually only goes for slimecoat when something is missing in the diet. Figuring out what is missing from the diet and making sure the BN is getting its share of the feed will, in time, end the slimecoat sucking.

BN's are not the only sucker fish to behave this way, even Otto will latch onto the side of a fish if it gets the urge to do so. And sometimes the fish do not wait til lights out to do it either. The Common Pleco is notorious for slimecoat sucking.

I also understand the difficulty when space at home is very limited, I am in the same boat there.
 
I feed at the front of the tnak - but a variety of pellets and a few flakes for the tetra. The amount I feed depends largely on the aggression (eagerness to eat) of the fishes. The BN is one fish that never comes to the front during the day - the L204 will come to the front when hungry (I actually have 5 in this tank; but they are different sizes so i can identify them easy enough). The clown loaches also have mystery snails they can snack on. As for the BN I doubt there is much left by the time it comes out at night - i would have to feed enough food to last for hours - i could try putting a few shrimp pellets (omega-one) in the back.

Is there any chance this is caused by a disease ?
 
That would be an issue

Never feed BN/Pleco when the lights are on and when everyone else in the aquarium is feeding

Only feed the BN and Pleco about 20 to 30 minutes after lights are out. They are nocturnal feeders so your BN is hungry at night after lights out, so its hitting the best food it can find...slimecoat from other fish that are static and slabsided.

From tonight, wait 20-30 minutes after lights are out. Feed spirulina flakes....two or three at each end of the aquarium. The other fish will sniff at them but will not touch them to the extent that they would at normal feed time for them. The BN and Pleco will feast quietly in the dark and both should be satisfied. Also once or twice a week let them have a slice of zuccini or similar, again each end of the aquarium to prevent food fights, remove any left overs in the morning.
 
I already feed zuccini twice a week. Why spirulina flakes? The pleco gets a lot of veggie matter the only thing that could be missing is protein.
 
I already feed zuccini twice a week. Why spirulina flakes? The pleco gets a lot of veggie matter the only thing that could be missing is protein.
Spirulina is an enriched form of algae food, it has a better level of vitamins and minerals than basic algae wafers/flakes

Putting zuccini and other blanched veg is great but only do it after dark, same with their wafers/flakes, you can also get specific protein enriched Pleco foods too.....your BN is not getting enough to eat as it is not a daytime feeder (nor is the L204). Feed at night and you will find that the hungry BN will leave the slimecoat on the Angels. It is simply subsidising the diet that it is missing. First thing in the morning before lights on or shortly afterwards, remove all uneaten veggies.
 
Have you ever seen angels do this sort of damage to each other with the ones you have ?
I have, I mentioned before angels can fight till the beaten one is dead. I have gone through this, I know there are way too many questions and speculations but soon as you mentioned "other angels" it took me back to when I had nothing but angels. It was never smooth sailing putting more than one angel in a tank, no matter what size tank, yet other times I've had 3-4 angels in tanks for years without any issues. In a couple of other instances I have woken up to a dead beaten angel, when there were nothing but angels in the tank. Taking the injured angel out till it heals and later returning it back to the original tank would be even worse IMO. I suggest you take a closer look and find the aggressor (ruling out disease) If it is a disease, I have never seen this, It looks like very clean deep holes.
 
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My most successful angel tank I had were 3 that I purchased dime size and for 3-4 years just kept on growing. I eventually re-homed them to a bigger tank. These angels were just a sight to watch, no pecking or chasing, I haven't been able to replicate this after a couple of attempts.
I hope this helps you a bit, again, just watching the tank for a while can give you an idea if the injuries are angel related or some other shady nocturnal character.
 
The damage is mechanical, there is no necrosis around the edges of the fresh wounds. The damage must be mechanical, either from another fish or from some place that the fish likes to frequent, sharp edge on a filter uptake that they like to swim behind for example. I have a number of Angels and sometimes they fight but I have never seen the damage like you have. I have also noticed that angel fry will feed on the slime coat of their parents so there must be some attraction to it. My first response would be to suggest the BN is the culprit, I don't know about L type pleco. They have sucker mouths and abrasive tongues which would create holes like what the picture shows. If this is the case it will be hard to modify the behavior of the culprit because they have learned this behavior provides them with high quality food, better to them than the zuccinni and other foods you provide. I would try separating the Angels from the Plecos.
 
The damage is mechanical, there is no necrosis around the edges of the fresh wounds. The damage must be mechanical, either from another fish or from some place that the fish likes to frequent, sharp edge on a filter uptake that they like to swim behind for example. I have a number of Angels and sometimes they fight but I have never seen the damage like you have. I have also noticed that angel fry will feed on the slime coat of their parents so there must be some attraction to it. My first response would be to suggest the BN is the culprit, I don't know about L type pleco. They have sucker mouths and abrasive tongues which would create holes like what the picture shows. If this is the case it will be hard to modify the behavior of the culprit because they have learned this behavior provides them with high quality food, better to them than the zuccinni and other foods you provide. I would try separating the Angels from the Plecos.
I'll put more effort into capturing that BN. I doubt it is the L204s because they come out to eat during the day and the angels are quite comfortable around them. The angels don't hang out anywhere near the filters - when distress they hang in the plants on the right side otherwise they stay in the open on the left - but they never go near the filter output. The intake has a sponge pre-filter (it is an fx6). I probably should have acted faster but didn't really realize just how bad it was getting. The large male bn never comes to the front during the day - he hangs out on the glass in the very back which i can barely reach. I do know he comes front at night sometime because i've been up at 1am and seen him on the zuc at times - but it is not on a regular basis and he quickly retreats when i shine a light (which i require to see him at night).
 
My most successful angel tank I had were 3 that I purchased dime size and for 3-4 years just kept on growing. I eventually re-homed them to a bigger tank. These angels were just a sight to watch, no pecking or chasing, I haven't been able to replicate this after a couple of attempts.
I hope this helps you a bit, again, just watching the tank for a while can give you an idea if the injuries are angel related or some other shady nocturnal character.
I've raised angels for about 5 years and while i've seen them do damage to each other - nothing similar to the type of damage i showed in the picture. The 5 i have left were all raised together from frys. I have 4 males and 1 female.

Anyway I'll spend an hour or so during saturday's water change and see if i can catch that bn. I've wanted to get rid of him for a long time now - but if he springs from the glass when the net enters the water it will be nearly impossible to chase him down. I just can't reach the bottom in the back very well.
 
All this said, have you seen any sign of aggression between the angels?
 

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