goldfish question, 10 points!!?

Question

I have 2 goldfish in a long 20 gallon tank. the male potbelly calico fantail is approx 3 inches, and the female oranda is much smaller at 2 inches.

initially when i introduced her to the tank, the male chased her around; typical mating behavior.

however, as of late, the female has been nipping at the tail of the larger male. now he has torn tails, so i've separated them with a divider. ive also seen the male rub his belly on the gravel twice. so im not sure if it's ick, or the female oranda.

has anyone heard of a smaller female harassing a larger male before? and if the male does have ick, would treating the tank with melafix destroy the biological filter?

10 points to the best answer! Thanks in advance.

Answer 1

You have a couple of options. Firstly, though, you'll want to take a look at the fish to determine what it has. If it's rubbing against things, it could very well be some kind of external parasite like hook worm, fish lice, etc. Mardel makes very good universal medicines for both the parasites, and fin rot as well. I mention fin rot because now that your fish has torn fins, a fin rot medicine will be a good preventative measure.
Another option would be a salt bath, which is a tried and true medicine for a lot of fish ailments, and would probably "kill two birds with one stone". Hope this helps.

Answer 2

First of all, i doubt it very much that you can know if these goldfish you have are are already mature enough to be sexed
you can't really sex them until they're about 1 year old, and even then they're extremly hard to sex
here is a site on how to do it, they're way to small to do so
http://www.bristol-aquarists.org.uk/goldfish/info/sexing-fs.htm

I would check your water parameters, i doubt it that the oranda nipped on your faintail

I assume that you're waterconditions are bad
I would check the ammonia and see what parameters you get, it's suppose to be at 0
It sounds like your goldie has finrote due to bad waterconditions
You're suppose to do 25% weekly partial waterchanges with a gravel siphon

And if it would have ick, you would see white spots all over him in the size of saltgrain

Please check your ammonia, and let us know how much it is


Hope that helps
Good luck



EB


Feel free to email me

Answer 3

Your fish are overcrowded, which causes stress, which in turn leads to disease. Goldfish grow to be quite large and need at lease 100 gallons. Fin nipping is another sign of overcrowding and stress. Do not treat your fish unless you are sure of what you are treating for.
What you need to do is get yourself a larger tank, 30 gal would do for now, and plan to upgrade as they grow.
With the proper care, your goldfish will live up to 20 years and grow to about 15" long.
In the situation you have them in now, I doubt they’ve got another year.

Answer 4

Yes, female goldfish can nip the males if they are DYING. That means your fish has a disease. Might be Ick if it has white spot. If not, it could be a cause of intestinal parasites or if you see a worm atached to it and color green, pull it out with tweezers.

Also it could be fish lice.