The Spider Decorator Crab is a small cryptic-looking specimen which masters the art of disguise by allowing the attachments of various anemones, sea weeds, sponges, bryozoans and other coral polyps to its exoskeleton. It is known to camouflage itself with the aforementioned animals and fastens them to its hooked setae on the back of its shell. Although, the Spider Decorator Crab remains stationary at one place but it moves at the time of feeding and breeding. It is basically an omnivore and uses its long pincers to pluck smaller animals from crevices and also scavenges on algae present on the sea floor. The Spider Decorator Crab is named aptly due to its similar appearance with spiders, and also due to its connection with the family of crab as well as spider, Majidae. It mainly gets its name as decorator because of it propensity to decorate its own body with shells or other aforementioned animals on itself. Although the crab can damage soft corals and polyps, but at the same time it usually ends up propagating and spreading the same organisms. It is very difficult to spot the Spider Decorator Crab or observe it in the tank when it is not moving. It may kill other smaller crabs, such as hermits, snails, and even small bottom dwelling fish. These crabs actually have tiny, Velcro-like hooks on their shell that hold their accessories in place. The shell never grows but the crab does, that is why the Spider Decorator Crab undergoes molting and shreds its old exoskeleton and forms a new and larger one. Generally, it removes the anemones, sponges and other decorations from its old shell and uses them to decorate its new shell.
These wild looking creatures are crabs that use algae, sponge, substrate and even corals to camoflauge themselves in the wild.
