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N. maculatus is a porcelain crab species from the northwestern Pacific . A small, colorful crustacean, this porcelain crab has an exoskeleton that looks like porcelain. The carapace is covered in red spots and blotches, while the underside of the animal has fine, evenly spaced red dots. Their two claws are huge, more than half the mass of the whole crab; and both claws are of the same size. They don't seem to use these oversized claws for attacking, however. They have been observed to use their claws to keep the space in front of their faces clear of obstruction to incoming food. All porcelain crab species are filter feeders. Below the eyes of the porcelain crab are two maxillipeds (mouth appendages) that have long hairs that form nets for trapping plankton. In calm water, they will wave their maxillipeds back and forth. But when there is a current flowing (as in the video), they will be content to hold the nets against the current. An interesting fact about porcelain crab: they have a high tendency to autotomize their limbs when caught. They can drop or discard a limb in order to escape predation.
Porcelain crab are usually found living commensally with a number of species of sea anemone (shown here: Stichodactyla gigantea), and the host's stinging tentacles do not cause them harm. Found at depths of 1 to 25m, across the Indo-West Pacific.
This porcelain crab couple were on a Gigantic Sea Anemone, sharing space with several anemonefish and some cleaner shrimp. This was at around 10m depth, at the Dayang Beach dive site, Talikud Island, Philippines. The video shows the larger of the two feeding.