Diagnosis And Disease

[tmiller619]

I have a pleco that is not acting sick but literally looks sick. I have attached pictures. Can someone please diagnose and tell me what to do, if anything. I bought the pleco about a month ago.
 
Side note: I have three older silver dollar fish that are losing thier fins too (I figured it was due to them being around 5 years old and it was just thier time but now I am not sure)
 
Any ideas?
Thanks!

 

[fluttermoth]

Ooh, that looks really bad, I'm afraid.
 
Fish are very good at not acting sick, even if they're on death's doorstep; acting sick, in the wild, attracts predators, so they often continue to behave as normal. If you didn't have other sick fish, I would have guessed at that injury being a heater burn, but there could some sort of pathogen involved.
 
We need the basic info from you before we can help more; how big is the tank, what's your maintenance regimen and have you tested the water at all? Exactly what fish and how many are in the tank?

 

[tmiller619]

30 Gallon Fish Tank with 4 tetras, 3 older (and large) silver dollar fish, 1 ram, 1killifish and 1 fiddler crab besides the pleco. Tank recently cleaned and filter refreshed. Have not looked into water quality issue, but I havent had a water issue in years.

 

[Ch4rlie]

Hmm, difficult to pinpoint this.
 
Even though you say you've not had any water issues for years, I'd still like to have some water parameter readings just to be sure before we discount water parameters.
 
Also, do any of your other stocking showing the same symptoms as the silver dollars and pleco fins?
 
Might have agreed with Fluttermoth about heater burns possibly on the pleco but this happening to your 3 silver dollars too makes me doubt this.
 
How long have you had the fiddler crab by the way?

 

[livelifelow]

When you say the silver dollars are losing their fins, what exactly do you mean?  Are they rotting off, falling off, or at some point you just notice the fin is not there?  If its the latter I would suspect your fiddler.  My family has been known to have  the occassional fiddler, lost a few fish, and didn't realize until the last fiddler had a fish in his claw what had been taking them out.