Whats this weird stuff in my tank/on my fish?

Question
Hello Chris, My 55 gal. tank has been set up for two weeks. In it, there is one large white Gold fish (with whiskers?) that I have had for three years (from out of my pond) and two small orange gold fish that I bought last week. The water chemistry is good and I use a Whisper filter system (for up to 60 gals. - doubles filter) and a under the gravel filter system as well. In the last three days my large fish has developed some kind of something on him. YUCK! It is gray/brown and round, yet flat. Do you have any idea what this might be and how I can get rid of them? Also, they seem to be on the large fish, only.  Thank you so much for your help! Lisa  

Answer
Hi Lisa;

Sounds like Argulus or "Fish lice". They are a parasite.

Here are some photos to help you find out for sure;

http://images.google.com/images?hl=en&lr=&ie=UTF-8&q=argulus&btnG=Search

If you know this is what the fish has you can ask the local fish store for a remedy. The lice aren't always the same color as shown in these photos but you can see the basic shape and appearance. Let me know if this isn't what your fish has.

Followups welcome

At Your Service;
Chris Robbins

Come on over and join us on the freshwater fish forum at About.com to get even more information too;
http://freshaquarium.about.com/od/questionsanswers/a/naavigateforum.htm

My member name is ChrisR62. See You There!