Why is my goldfish's tail gone?

Answer by  PhillyFan (86)

It's mostly likely due to other fish in the tank. If you have aggressive fish in the same tank (such as Jack Dempseys, oscars, puffers, etc) these fish may have nipped off the tail. It may also be due to illness or parasites, such as rot or ich.

Answer by  John (9008)

There are two possibilities. The first possibility is that your fish has a disease called tail rot. This disease is common in fish, and can be fatal. Fortunately, you can buy medicine to add to your tank to cure it. The other possibility is that other fish are attacking it.

Answer by  Abbie (282)

If there are other fish in the tank it is most likely that the two fish were fighting with each other, and the larger fish could have torn the fin off.

Answer by  tuppyqueen (311)

Sounds like you have a sick goldfish. When some fish get sick they start missing parts and then other fish eat them

Answer by  BlindMag (161)

If you are keeping your goldfish with any other type of fish it could have been lost in a fight. Otherwise poor water conditions can cause fin deterioration.