Yes they do.
koi is scale becomes red when the koi is breath some carbon dioxide and hipothetic acid so it affects the scale
Skin that they regularly shed a layer of as they grow
of course not
No.. They shed. They dont have scales they have fur. So they shed. Which is when their fur falls outs.
They shed their skin then they eat it
Yes, all snakes shed their skins. They do this to grow. It enables them to be renewed, the new scales are brighter.
No it's called shedding
No. It may have scales but it is not snake-like.
Goldfish have scales rather than hair, and as such, they do not shed
Their 'skin' is made of a layer of bony plates (not really skin then). These bony plates are really just modified scales. They cannot be shed.
Freshwater Angelfish don't shed.