Not sure the best flair, just wanted to share somewhere with others that might be interested that we did finally catch the Juli Corydoras in my 11 gallon tank swimming upwards and nibbling on my betta fish's(Diablo's) fins.
Diablo never gives them space when they're eating, trying to crowd them and steal food that flies up or that he can see on the sand near them. So, in the mix up I assume they nibbled him occasionally for the last two months creating crinkles in his fins but never tearing them. Finally, two nights ago I could finally confirm an outright tear on his tail, and that same day caught the largest cory swimming upwards towards him and grab his tail for a moment before he swam away slowly. Diablo is so dang chill he just lets them nibble him as far as I can tell.
We're currently a week into cycling a six-gallon long tank that I was planning for a new fish, but it looks like Diablo will need to go into it by himself asap since he took another fin tear overnight despite giving extra food to the corys before lights out.
I feel bad I believed others when they said the corys couldn't possibly be causing his fin issues when I first started having concerns, so just wanted to provide others with my own situation. Every fish is unique of course.
Has anyone else reading this had their bettas get nipped by the unexpected fish? I'm water changing and testing the six gallon today in hopes he can get moved into it, but I don't want to rush him into an unfinished cycle – any advice to help prevent more fin damage until he can get moved? Really hope his fins heal back to their full pretty fans.
*If you're going to accuse this of being fin rot- do not waste the time commenting please. I'm not responding to frivolous comments regarding this tank that has perfect water tests and healthy plants – these are clean chunks being bitten off of his fins. The only thing we guessed otherwise was tearing on decorations, but there's no edges for him to tear on the hardscape present. This discussion is NOT about 'what is causing his fin damage' anymore – we physically WATCHED him get nibbled on we KNOW what is causing it.
https://www.reddit.com/gallery/1qdox8d
Posted by JazziniBear
8 Comments
That fish is beautiful!
Are there other tankmates? This is unusual.
Its very very unlikely that it was the corys this is 100% outside normal behaviours for them. The only way I could see this happening is if the corys haven’t been getting enough food or they are stressed as hell because 10gal is well below the minimum size requirement for corys.
They likely don’t do this. This could be fin rot.
Ive had haborus corries with my beta for over a year now and no issues. What’s your water quality? Could it be finrott?
What’s crazy to me is that people don’t realize, *any* fish species is capable of becoming a fin nibbler. Just because *most* of the time they don’t, doesn’t mean *they all* won’t, 100% of the time.
I can’t tell you how many times I’ve heard “they’re suppose to be so docile but I saw with my own two eyes, they were bullying and nipping at my betta!!!”. Like yeah. If it’s a long finned betta, they **should** be kept alone minus shrimp and snails. Other fish species are going to act out of instinct and seeing a slow moving, long finned fish just triggers them to wanna try to eat it. 🤷🏻♀️
It’s **always a risk** keeping long finned betta with any kind of other fish tank mate.
Thank you for posting this and reminding me/everyone that just because something doesnt USUALLY happen, doesnt mean it definitely WONT.
Fish are individuals just like any other species, and what may be true for most may not be true for some. We also sometimes forget that the betta isnt the only creature to worry about when planning a community tank as some bettas are not super aggressive to other species (contrary to popular belief) but their tank mates might be a problem, and the only way to really know is to test and see, with a backup plan in place if it doesnt work. My plakat betta has no interest at all in his shrimp and pygmy cory tankmates aside from what they might be eating that he would like to steal for himself, but this is a good reminder that things can change and what works for one (person, betta, tankmate, setup) may not work for another.
Glad you caught the behavior and were able to decisively pin down the cause so you can make changes and keep all species happy and safe!!
11 gallons is too small for corys. Im also hoping you have a proper shoal of atleast 6. 20 gallons is the minimum for them (20 long is preferred). Corys dont nip so the cause is either: stress, hunger, an overstocked tank or poor water quality. In this case, since you said they were eating, im gunna go with stress from being in a tank thats too small. The water quality could be playing a factor too. Smaller tanks are harder to maintain. Downgrading Diablo isn’t fair at all. You should keep him in the 11 gallon and get a 20 gallon long for the corys. You could even put everyone in the 20 long. Im sure everything would work out with the extra space.