Not heard or seen that before! You got a photo mate? Do you mean on his back?I've just come home to find that one of my cleaner shrimp has moulted! What I wasn't expecting is the colour of him... the parts of him that are usually white are kind of brown? Presume it's the the shell hardening?
It's his back yeah, just trying to fish it out.... he's plodding around and seems happy enough, they both hide around the back of the tank though so it's difficult to get pictures!
Are cleaner shrimps ok to go in with my peppermint shrimps?