Expert: Tom Lee - 11/7/2009

Question
the biggerst gold fish keeps chasing relentlessly after one fish .i would think its a male after female he wont stop utill i take him out in small tank solo over nite than when he goes back he is good for a week or so and than right back at it. he nudges side of white fish you can see the bruses I  think he will have to go for this is third time I have removed him but I DONT WANT TO GET RID OF HIM.. ANY SOLUTIONS ?

Answer
Hi Jayne,

It's unlikely that it's a male chasing a female. Goldfish are suprisingly difficult to breed. Breeding requires carefully monitored water parameters, temperature and water levels. To be honest I think it's probably the two of them jostling for position as top dog within the tank. Goldfish loosely shoal together, and there is usually a heirachy within a community tank. At the moment the heirachy is firmly established. Try moving the decor in the tank around, then you will split the pack apart and all fish will be on equal terms. The heirachy will establish itself again, and it's likely he'll continue chasing. I wouldn't worry about it, he's unlikely to do any harm.

Tom