It is easy to keep a few species in a marine aquarium, to take advantage of their
bright colors. These invertebrates are carnivorous: in an aquarium they should be
fed on mussels, fish, or white meat.
Hermit crabs are highly striking invertebrates which run
around the aquarium in all directions to look for their food. They withdraw into
their shell when frightened.
These rarely swim and prefer to get about by walking on the decor. If they are
disturbed they abruptly recoil by tucking up their abdomen. Several specimens can
live together, but it is vital to keep them away from carnivorous fish.
Enomotoplus sp., the lobster crab, related to the langoustine,
is an attractive and placid resident.
The small abdomen is tucked under the lower part of the body. Their pincers are
particularly well developed. The larger specimens, which can be aggressive, must
not be put into marine aquariums, as they can attack other invertebrates, and sometimes
These are better known as hermit crabs. Some tropical species can be found commercially,
some of them bearing a small anemone on the gastropod shell which houses them. The
shell is discarded when it becomes too small for the growing animal, so it is vital
to provide bigger ones, as, unlike other crustaceans, a pagurid's abdomen is not
protected by a carapace that it makes itself.