[Shonick2]

Please see attached pictures. Do you know what kind of bug attached to my casara goldfish? When I touched it, I feel kind of hard. Definitely something attached to it. Can it contagious? And how to remove and fix it?

Thanks

 

[Mark Fisher]

I'm guessing it is a fish louse, Argulus sp. It's a parasitic crustacean, not a bug.

This species affects goldfish: https://www.about-goldfish.com/goldfish-lice.html

 

[Shonick2]

Thank you. That helped. I manual remove it. I hope my fish recover soon and not affect it again.

Look like this parasite is stubborn than the one in the article. After 24 hours it is still there. In the article, it says it will remove themselves in 2 hours.