My goldfish "chewed" off his tail and dorsal fin - - what is wrong with him???

Question

I recently moved my goldfish from a 1 gallon tank to a 5 gallon tank (once I learned the 1 gallon was too small). He gets plenty of light during the day, I make sure to feed him, and I treat his water every time I do a water change. I moved him into his new tank last Thursday, and when I came back to work on Tuesday, he was happy and healthy, had eaten all of his "vacation" food pellet, and was exploring his new home. However, when I came into work on Wednesday, his tail had been, for lack of a better word, chewed off, as was his dorsal fin ( I know it isn't possible for him to successfully reach either with his mouth, but it sure looks like something was gnawing away at him.) He is still able to swim around and he eats his normal amount of food. His water has also turned a very sour-smelling yellow, despite the new charchol and bio-filters. Any ideas on what is wrong with him? Is there anything I can do to help him?

Answer 1

Either he is hungary or there is something else swimming around in there with him...

Answer 2

Its called fin rot and there are lots of meds to help it heal but first you need to find out why the fish got it in the first place. It is usually from bad water like high ammonia or nitrite. Those vacation feeders aren't a good idea either, they can really mess with the ph of the water and cause the fish stress which could be a reason for the fin rot too. Test your water or bring it to a pet store to get it tested and make sure everything is fine, which means zero ammonia and nitrite, 20 or below nitrate and ph around 7. The next time you are away from the fish for a few days just let him fast, it is good for cleaning out his system and keeps the water cleaner.

Answer 3

use Melafix and after he is cured call the circus cause you have a very good contortionist if he ate his own dorsal fin, lol, nah, its just fin rot oh and the sour smell is tooo much amonia in the tank, its a new tank as far as you are saying so the cicle is just happening now, what to do? water changes 1 per day untill amonia gos down.

Answer 4

your fish has fin rot, please medicate as soon as possible
your fish cannot reach his dorsal or tail fins to chew them off
also add aquarium salt as a medicinal treatment

Answer 5

my daughter's did this too. didn't have the "sour" smelling water though. he lived quite a long time like this then finally died. never knew what caused it. Good luck.

Answer 6

sometimes fish can have rare mental disorders, and suicidal or self destructive tendancies. It probably means that your fish is depressed, I say get him a girl fish(or if it is a girl, the a guy fish)

Savage

Answer 7

MELAFIX!