Crabs are an essential cleaner, but not all are safe for coral reefs.
There are many different species and they vary in size and structure. Crabs are remarkable scavengers that are constantly removing algae and
debris tucked deeply into coral reefs and rock reefs. They do well in
any environment and are generally peaceful. Some Crabs, however, can
be more aggressive, so it is best to allow them plenty of space and
extra food when needed.