Hi - It has been many many years since I had aquariums and knew what I was doing in caring for fish so I now have a question I hope someone can answer for me. My grandson has two small goldfish in a 2 gallon aquarium (Goldie and Goldiefish). When we brought them home Goldie had been nibbled on - her (his?) tail was practically non-existent. Well, they have grown and thrived and Goldie has a beautiful new fan tail and they've always gotten along very well. Two days ago I noticed that Goldiefish has taken a couple of bites out of Goldie's beautiful new tail. I slid the beta screen into the aquarium to keep them separated until I figure out why this is happening. I at first wondered if I hadn't fed them enough and Goldie was just hungry but doubt that's the problem. I wondered if one may be male, the other female & someone got a little too frisky . . . Any ideas?? Thanks, Sheila