Hole in leopard danio

[Loulo717]

I have a 10 gal tank with 6 leopard danios and 4 adfs, they have been in the tank for just over 2 months now. I noticed this morning that one of the danios has a hole in it, it almost looks like either a bite or it’s rotting. It’s acting normal, eating. I tested the water and everything is in safe perimeters and no sudden changes to anything. I can’t see anything like this on any other fish.
I tried to take some pictures and got some blurry ones, hopefully they will help. Please help!

 

[FishGuest5123]

It does look like a bite but not sure a bite would show the dotted pigmentation that deep down. They are normally peaceful fish but they do like hiarchy and will at times, get aggressive to obtain it. Normally very hardy. Anybody else? Keep the water extremely clean. If it worsens I would get a bacterial med such as Furan-2 and try that. You need a much larger tank for the danios, at least a 20 gallon long. They like to swim and are fast. The tank being too small can also be causing aggression. Good luck!

 

[Loulo717]

It does look like a bite but not sure a bite would show the dotted pigmentation that deep down. They are normally peaceful fish and very hardy. I would suspect the frogs, myself. Anybody else? Keep the water extremely clean. If it worsens I would get a bacterial med such as Furan-2 and try that. Good luck!

The fish do swim down by the frogs food when they are eating, the placement of it just seems a little odd to me to be a bite and I’ve never seen the frogs try to bite them but then again I’m not constantly watching them! I guess I’ll just keep a close eye on them and see if it worsens or spreads. Thanks for the input!

 

[FishGuest5123]

The fish do swim down by the frogs food when they are eating, the placement of it just seems a little odd to me to be a bite and I’ve never seen the frogs try to bite them but then again I’m not constantly watching them! I guess I’ll just keep a close eye on them and see if it worsens or spreads. Thanks for the input!

Please note my edited reply.

 

[Loulo717]

Please note my edited reply.

I have noticed the biggest danio chasing some of the smaller ones. At this point I’m assuming it’s a bite but will keep checking for it worsening or spreading to other fish

 

[Essjay]

I would not rule out the frogs. They are almost blind and find their food by smell. If they see something moving near the food they will lunge for it as they can't see well enough to tell the difference between food and a fish.
Once, many years ago, I had adf's and a betta in the same tank. I found the betta frantically swimming round the tank trying to dislodge the frog that had clamped onto his tail. I suspect something similar could have happened to your danio.
I solved the problem by setting up my quarantine tank and moving the frogs into that. Deanasue suggested a bigger tank for the danios, and I would second this, leaving the frogs in the 10 gallon - just the frogs, no other fish. In a small tank like 10 gallons, the danios will be stressed and stressed fish behave out of the norm, either becoming reclusive or more aggressive than usual for the species.

 

[Loulo717]

I would not rule out the frogs. They are almost blind and find their food by smell. If they see something moving near the food they will lunge for it as they can't see well enough to tell the difference between food and a fish.
Once, many years ago, I had adf's and a betta in the same tank. I found the betta frantically swimming round the tank trying to dislodge the frog that had clamped onto his tail. I suspect something similar could have happened to your danio.
I solved the problem by setting up my quarantine tank and moving the frogs into that. Deanasue suggested a bigger tank for the danios, and I would second this, leaving the frogs in the 10 gallon - just the frogs, no other fish. In a small tank like 10 gallons, the danios will be stressed and stressed fish behave out of the norm, either becoming reclusive or more aggressive than usual for the species.

Thank you so much for your advice! The guy at the pet store helped us pick the danios out for our tank, which is frustrating because he said they would be fine in a 10 gallon!
He also said that they would be fine with the frogs because they are generally peaceful fish but mentioned nothing about how active they are compared to the frogs. We are learning, slowly but learning!!

 

[Essjay]

One of the most important lessons in fishkeeping is never believe the shop until you have researched it for yourself. While there are some very knowledgable shop workers, most of them don't know or don't care and will say anything to make a sale.

Seriously Fish is just about the best website for research, this is their entry for zebra danios http://www.seriouslyfish.com/species/danio-rerio/ You'll see in the notes at the bottom of the page that leopard danios are a colour morph of zebra danios so their needs and care are the same.

 

[Loulo717]

One of the most important lessons in fishkeeping is never believe the shop until you have researched it for yourself. While there are some very knowledgable shop workers, most of them don't know or don't care and will say anything to make a sale.

Seriously Fish is just about the best website for research, this is their entry for zebra danios http://www.seriouslyfish.com/species/danio-rerio/ You'll see in the notes at the bottom of the page that leopard danios are a colour morph of zebra danios so their needs and care are the same.

Thank you! I will definitely check that out and I’ll probably end up taking the fish back as we do not have a bigger tank for them to go in.