3 striped damsel fins...

[Snorkeler24]

In my tank I have one yellow tailed damsel, one 3 striped damsel, one banded coral shrimp and a lettuce sea slug. I've noticed that my black and white damsel looked like he had a piece bitten out of his left fin. It has gotten worse and almost looks like its deteriorating. He began getting a little spot that looked like a hole on his back fin. Now the hole in his back fin turned into a slit and he seems to always swim upright, vertically like he is a human! Is this because his fin is cut and is it some sort of disease? My yellow tailed damsel seems fine. Any ideas?

 

[TimSchmidt]

Aggression in the tank?

 

[Snorkeler24]

not that I have noticed. At first I thought that the black and white damsel was the bully. But everything seems to be pretty peaceful. I was afraid it was fin rot. SInce this is my first salwater tank, i dont know a lot about diseases.

 

[TimSchmidt]

Pic?

 

[Snorkeler24]

ill take one tonight

 

[Snorkeler24]

he is pretty much lying on his side now. i dont know if he can even swim up to eat. it looks like he wants to. id take a pic but you cant see his fins at all, hes just lying under some rocks.

 

[TimSchmidt]

You are probably right then and it has fin rot. It may also have a swim bladder infection. If that is the case then water quality could be a culprit. Not sure though. I am just taking a stab at it.