Who is the likely culprit?

[lilly]

I have a 20 gallon cycled tank with 1 panda cory, 5 julli cory and 10 green eye rasbora. They are all small right now.

One rasbora is missing, I can't find it or any remains. They are really hard to count as they move so fast but at one time, there were 10. One cory has had his tail eaten.

The fish were added one week apart and I never see any chasing or nipping. I understand that if the rasbora died, he might become a snack. I am more concerned with the cory's tail. Poor little guy.

The water tests at PH 7.4, Ammonia 0, NI 0, NA 10.

Thank you!

[GirlieGirl8521]

Is it possible you bought the cory like that? Neither cories nor rasboras are nippy fish, so I doubt any of them did damage to the injured cory. If you didn't buy it like that, it could have fin rot. The rasbora most likely died and decomposed. Small fish like rasboras are easily missed when they pass.

[SmallFishi]

It probably died and then maybe the cories at the body, they wouldn't have killed a fish that wasn't dying or dead already.
As for your cories tail can you take a picture it may be fin rot.

[jwddboy]

The cory's tail will most likley be fine. Fish that have recently been moved or have had an accident, often have slightly ripped tails or fins that heal quite quickly.

[curviceps]

treat with a little Melafix and the tail should be fine

[jm1212]

did you check around the tank? the fish couldve jumped out of the tank between the filter and the hood.

[lilly]

Thanks for the great suggestions!

I do think I would have noticed if he had a nipped tail before but it's possible I missed it. It doesn't look like fin rot, I'll post a photo if I can get him to hold still!