Chunk Missing from Tail!

[LolaQuigs]

I got home today and found my new(ish) halfmoon male is missing a huge chunk out of his tail! I don't know how this could have happened! I can't imagine there's anything in there he could have caught it on; the filter intake is covered with pantyhose, all of the plants are silk, and his cave is a smooth clay pot. Could it be tail-biting? If it is, what can I do to prevent this from happening in the future?

Housing
What size is your tank? 2.5 gallon
What temperature is your tank? 80
Does your tank have a filter? Yes
Does your tank have an air stone or other type of aeration? No
Is your tank heated? Yes
What tank mates does your betta fish live with? None

Food
What type of food do you feed your betta fish? Omega One Pellets
How often do you feed your betta fish? 2xper day, 2 pellets each feeding

Maintenance
How often do you perform a water change? 3xper week
What percentage of the water do you change when you perform a water change? 50% twice a week, 90% once a week
What type of additives do you add to the water when you perform a water change? Prime


Symptoms and Treatment
How has your betta fish's appearance changed? Fin Damage
How has your betta fish's behavior changed? No
When did you start noticing the symptoms? Just now
Have you started treating your fish? If so, how? No
Does your fish have any history of being ill? Recovering from fin rot
How old is your fish (approximately)? 1 yr?

I got him about three weeks ago, he had fin rot so I did a salt treatment for eight days. He's been in his regular tank for a couple weeks now and I just noticed this today! I have no clue what could have caused it, and I'm terrified that it will happen again.

Is there anything I should do to treat him? I would normally do water changes twice a week, but because he recently moved out of qt for fin rot, I have been giving him an extra one. He had one last night. He was fine this morning, but could the water changes be stressing him and causing tail biting?

I am reluctant to add aquarium salt because he just had a salt treatment so recently, and I think my water change schedule should be keeping his water conditions pretty good. Is there anything I should be doing while he heals?





(the white spots are dust on the tank, they're not on him)

[tokala]

Uh oh, how frustrating :( Was his fin rot cured before this happened? If not, maybe it was irritating him so he bit it? Like scratching and itchy, healing wound? Maybe he is a chronic biter, causing the fin rot from the beginning? I am so new to this I have no idea, but I hope it heals up fast. He is beautiful!
PS I treated Siku with an anti fungal for a few days to jump start the healing process from his fin rot/tail biting and there is a good mm of new growth now in just a week.

[small fry]

Do you have larger rocks (bigger than gravel) as substrate? I moved Tony to a tank that had rocks and didn't even think about what it would do to his tail (he has gravel now). Hope your bettas tail gets to looking better soon!

[LolaQuigs]

No, it's just standard black gravel. I just can't figure out what happened. Hopefully it's not chronic tail-biting, or something that will happen again.

[LolaQuigs]

I just checked on him again, and this situation is now URGENT.

It's only been a few hours since I first noticed that chunk missing from his tail, and when I checked again, a huge portion of his caudal was missing. I'm so scared that I'm going to wake up in the morning and find that he has completely ripped off his caudal fin. If anyone knows whether that looks like tail biting, or he tore it on something in the tank, please tell me!

I'm am putting him back in his quarantine tank. It's a 1 gallon bare bottom container with a single silk plant, floating inside a heated 5 gallon. He was fine in there for his fin rot treatment and I know there is nothing he could tear his fin on in there. I suspect it's tail biting but I can't figure out why, and all of a sudden. My mom had taken some pictures earlier today, and thinks it might be the flash from the cameras stressing him out, so I don't want to take any more pictures to show what his tail looks like now. Maybe it had something to do with the water change I did yesterday, I don't know. In any case, he's obviously getting new water when he moves back into his qt tank.

If he does ok in qt I might remove the filter when he's ready to go back into the 2.5 gallon. I baffled the hell out of that thing, and there is NO current coming from it, but maybe he's just extremely sensitive.

If anyone has any advice or suggestions I would really appreciate it. I'm so worried about him right now. Should I add aquarium salt to his qt tank, or is he fine with just daily water changes?

[LolaQuigs]

I just checked him a couple hours ago and saw that now his dorsal fin is shredded too, and his caudal fin is a tattered stump. I just don't know what I can do to help him, I'm completely at a loss.

[tokala]

Oh no!! I wish I knew something to say- so strange and upsetting! Is there anything in his environment that could be stressing him out- like seeing another fish constantly? I hope he calms down ASAP, but it sounds like a lot of it is out of your control which is the most frustrating part :(

[LolaQuigs]

Thanks for your well wishes and concern, it's definitely frustrating not knowing what's causing this, and not being able to do anything about it. My other betta is all the way across the room, and because of the angles/locations of their tanks I don't think it would be possible for them to see each other. I am trying to keep the lights off in the kitchen in case the light is what's stressing him. When I do tomorrow's water change, I think I will steep some decaf green tea in his new water; maybe the darker water will help calm him down. Other than that, I don't think there's anything I can do besides just keeping his water clean and hoping he settles down. Unless the water changes are what is stressing him? I really don't know....

I turned off the flash and snapped a few quick pictures. He has completely destroyed his fins in such a short period of time.

[Capricorn]

How frustrating.. Nettle did that to me. e.e He bit every fin down so far that he looks like a plakat right now.

Unfortunately if you can't eliminate a possible source of stress, he could literally just be bored. Try tossing in a ping pong ball to see if he'll pay attention to that and not to his fins.

[vilmarisv]

Oh no! You definitely have a tailbitter.
It's not something that's always caused by stress. As Capricorn said, he could be bored or he might have discovered that it's easier for him to swim without the weight of his fins. Some will never stop the behavior.
If you think it might be due to stress, try covering the tank with a towel so he cannot see what's happening around him.
I actually do will all my fish when I notice signs of stress for a few hours until they settle down a bit and with my spawning tanks. It keeps them from being distracted with what's going on outside the tank.