whats the crystals in the skin of fish?

Answer 1

If the crystals look like grains of salt, or like air bubbles then you probably have ick. You need to go to the pet store and gat a good ick treatment and follow the directions with the bottle.

Answer 2

I'm not exactly sure what you're seeing that you're calling crystals.

If these are white bumps like pimples on the skin of most species, this could be a parasite (ich) that's infecting your fish: see photo of ich on a betta: http://www.fishjunkies.com/images/ich1.jpg

I have to specify "most" fish, because male goldfish and some other members of the minnow family get these when they're in breeding condition. In this case it occurs just on the head (gill covers or top of head and neck in the front of the dorsal/top fin) and along the front edges of the fish's fins: http://www.bristol-aquarists.org.uk/goldfish/info/info.htm - goldfish http://www.univie.ac.at/anatomy/fish/pp04pics/10a-bearbeitet.jpg - minnow

You might also be seeing the chromatophores, or pigments that produce the fish's colors: http://cool.iitp.ru/projects/posters/cornea/pa.jpg The iridophores, which cause iridescence or metallic colors, may particularly look like crystals when seen up close: http://www.angelsplus.com/images/irides.jpg

Answer 3

Are you thinking of guanine? It's what gives fish scales the shiny appearance......

Honestly, I passed on this question for a while because it really had me stumped. I pulled out an old reference book and looked it up because I'd remembered reading a reference to "crystalline substance". I'm not sure if this is what you're thinking of. If not, hopefully one of the other answers will help you out.

Answer 4

Scales...