My Gold Fish Are Fighting

[snagglepuss2k]

my two gold fish which have lived together for about 6 years have started fighting the 1 that is slightly larger than the other one has started chasing it round the tank and nipping at his tail pulling bits of, what should i do should i seperate them.

 

[black angel]

what size tank are they in? goldies can get territorial if the space is too small.
how big are the fish as well?

if it was mating behaviour he would be driving her around and pushing from behind, and shouldnt have fin damage...do you notice this behaviour more at feeding time or is it constant?

 

[snagglepuss2k]

the tank is 30inch x 16inch x 14inch the fish are about 3inch & 5inch the nipping has only recently started the only fin damage is on the tail. it isnt just at feeding time it seems to happen randomly.

 

[ColdGold]

The tank is too small.