A small banded hermit crab in a borrowed turban shell, two centimeters (0.8 in), and one of the most numerous animals on any rubble slope in this sea.
Hermit crabs of this size are the reef's cleaning staff. They work over rubble and dead coral through the night, taking algal film, detritus and anything dead, and there are enough of them that the effect is measurable: a patch of reef without hermit crabs accumulates organic matter that would otherwise be gone by morning.
The shell shortage that governs the whole group is at its sharpest here, because small shells in good condition are the ones everything wants. Empty shells rarely stay empty for more than a few minutes.
It is called hidden because it withdraws completely, seals the opening with the larger left claw, and becomes a shell - which is what it looks like whenever anyone approaches, and why almost nobody has watched one for more than five seconds.
- small hermit crab, olive-brown with pale bands on the legs
- eyestalks pale with a dark band, eyes orange
- in small turban and nerite shells on rubble
- length up to 2 cm
