Unfortunately, little information is available aabout this pretty and interesting coral shrimp. They live in coral of different types, so far it was not figured out whether certain species are preferred. However, most specimens were found in Acropora species, but also in some Pocillopora species. As far as is known they do not feed on coral polyps, but feed on mico plankton.
Since Coralliocaris sandyi is already to be found very rarely in nature, you can assume that it will be rare to find in the trade as well.