Mandarin diagnosis?

[CardiNole]

Hello, I have a pair of biota mandarins. Both are eating like pigs and growing. However they appear to have something on their skin. The other fish seem fine. Any idea as to a diagnosis?

 

[CardiNole]

Hello, I have a pair of biota mandarins. Both are eating like pigs and growing. However they appear to have something on their skin. The other fish seem fine. Any idea as to a diagnosis?

Better pictures

Hello, I have a pair of biota mandarins. Both are eating like pigs and growing. However they appear to have something on their skin. The other fish seem fine. Any idea as to a diagnosis?

Better pictures

 

[javisaman]

Are those pictures from the daytime or at night? They pale out and look slimier at night.

It almost looks like sand to me. If it was velvet or ick, I would think that it would be more uniform throughout the entire body.

Do they get along? Sometimes when they are stressed they also slime up a bit more too. I had a male/female pair, they were fine for about two years until the female started attacking the male and the skin around the back of its head was raised because the female kept biting it.

Either way hope you figure it out soon.

 

[CardiNole]

It's a nighttime picture. It honestly looks like sand, but I haven't seen it before. They do seem to get along.