They are the roly-poly backpackers of the brachyuran scene. Portunids bristle with sharp claws and a surly disposition, while xanthids come with muscular arms and tight grips that promise more than a pinch of pain. Dromiids are said to be unpalatable delicacies, but these primitive crabs generally pose no major risk to limb and life, granting encounters that threaten merely to unleash a plump demonstration of soft power.
These clumsy-looking crabs usually suffer a chronic lack of haste, as their joints creak for want of unwelcome attention and the burden they bear on their backs. A few individuals at Beting Bronok, however, sped around with terrible complacency, confident perhaps that one cool hour of darkness would pose no threat to a rush across the reef. Like another specimen caught out in a state of dire underdress, this fellow made one move too many and found its hide overturned to reveal a carapace of stout indignance.
Two skinny pairs of legs are all that hold up a mountain of pores that has been tailored to suit the girth of its mover. From an early age, young dromiids select a hideout of filter feeders which they cut out and trim to fit. Sponges off the shelf are often too straight-laced for rotund shells, so the crabs have been observed to press the tissue tightly against its back, while bending it into shape. With time, the porous colony grows to match the concavity of its carriage. Foodwise, dromiids are said to have a weakness for sea stars.
Crabs in captivity are are reported to grudgingly accept unorthodox fabric like paper or clay, applying a paper-doll technique to snip out complementary ellipses. These flimsy caps are rapidly discarded should the animal come across natural substitutes. As the crab grows, the sponge presumably prospers from a free ride to richer waters and enhances its mass with glassy peaks and silica valleys. This individual's blue-green garb has become an ecosystem in itself, with hollows that hide brittle stars and cosy nooks where tiny porcelain crabs and even minuter isopods perch to take in plankton that rain down from the silty swirls of a shallow sea.