1.Suckermouth Catfishes (Family Loricariidae). Loricariidae is a relatively primitive group of fish. Also called “armored catfish,” Loricarids
2. 50 gallon tank with 4 goldfish few rocks on the bottom.
3. Water change monthly, filter change every other week..
4. He is the new one to the tank. That in his mouth is on his second day.
5. Currently 68-70°. Common neutralizer buffering for chlorine and other water treatment. Ph 6.8... not sure of nitrates...
6. He eats Algae pellets w/larvae , some beef, and romaine lettuce..
Thank you for your immediate response....
1. Even as a loricarid, there's a specific species (because there are well over 600), which could help pin down some concerns in the type of habitat/diet is proper, but generally speaking, the species here that I'm familiar with are fairly warm water fish, preferring temps in the mid to high 70s.
2. Tropical water fish and cold water fish like goldfish aren't a good mix. The temperatures for each to thrive are too different.
3. About what percentage? What do you mean when you say "filter change?"
4. I got nothing
5. Temp is probably too low for him. What neutralizer do you mean by common? PH should be fine, as that's not a crazy extreme number. Ammonia, nitrites, and nitrates *could* be something that causes a secondary infection, bacterial or fungal, to occur. Numbers greater than 0 for ammonia or nitrites is bad, nitrates above 20 is a pretty good indicator that it's time to do a water change. I'd recommend investing in a good liquid test kit, and testing regularly.
6. What kind of larvae? What kind of beef?
I'm just trying to pin down more details to get you more information. I'd say that if it's a growth, hopefully it's a fungal one that can be removed, and you can watch for a return and/or treat with a catfish safe fungicide. That's usually not a primary ailment, so it could be poor water conditions (quite possible sharing a 50 gallon tank with goldfish) that have weakened his immune system. That said, hard to say that it's because of *your* tank if he sported that on the second day. There may be other issues at play, too.