I have two fantail goldfish about the same size (3 inches long and 2 -2.5 inches deep). The one chases the other around constantly and I have had to remove the one being followed because it's tail fins are getting shorter and tattered... Is this some type of mating thing going on? This behavior has been progressing over the past few months and I am unsure why.. I have a male betta in with them -- he isn't being chased by the nasty goldfish either, so that is why I was thinking maybe a mating issue.... I haven't notice any other physical changes in the goldfish or anything... Should I keep them apart forever or return the meany??? thanks,, ang

I sounds like a mating thing to me but I'm not sure if it should be lasting for months like you said it was. Some salt will help the fish with the torn fins heal better and faster.

it is probly a teritorial thing or mating wut size tank do you have and how many fish"? bettas shouldnt be put with goldfish even if they dont bother eachother. the betta needs wormer water and also the movment in the tank in a goldi tank will be too much for the betta and he will have a drasticly shorter life. i agree with puting salt in the water to help heal and provent infetions.

poor thing.yah sounds like love is in the air!!!LoL that happened to my fishies....but with a really bad ending

looks more like a mating thingy..

if the male is far too aggressive, then you might want to isolate him for a while..

Well,, actually temperature wise the betta is perfectly fine because I keep my goldfish at 76 and that is perfectly within the temperature range for both species.... I am not concerned about their co-habitation... my betta has lots of floating cover for hiding and appears unfazed by the goldfish...
Anyways... I have the two goldfish in a 25 gallon (betta too)... I have isolated the abused goldfish (into a fully cycled ten gallon... I shifted the resident guppies in to my 20 gallon) and have used salt and melafix to heal the damaged fins which are coming along nicely... I may keep the two goldies apart forever now... I can mix things up a bit to give the meany the 25 gallon and the abused one a 20 gallon... I am just about to move and may set things up like that when I settle my new tanks... Thanks for the help all!!!

Yeah, so I posted about my fish in the Diagnosis section on my goldfish and their hurt fins. I have a 10 gallon tank, what kind of salt should I add and about how much for this size tank?

Thanks much!
Jesi