Mictyris is a genus of brightly coloured crabs, placed in its own taxonomical family, the Mictyridae. It inhabits the central Indo-West Pacific region. These crabs congregate on mud flats or beaches in groups of a few thousand, and filter sand or mud for microscopic organisms. They congregate during low tide, and bury themselves in the sand during high tide or whenever they are threatened. This is done in wet sand, and they dig in a corkscrew pattern, leaving many small round pellets of sand behind them.
Species
The genus contains eight species: Image Scientific name Distribution Mictyris brevidactylus Stimpson, 1858 Japan, China (including the type location, Hong Kong), Taiwan, Singapore, and parts of Indonesia (Karakelong, Bawean and Ambon Island) Mictyris darwinensis Unno & Semeniuk, 2011 Australia(Kimberley to Cape York) Mictyris guinotae Davie et al., 2010 Ryukyu Islands of Japan Mictyris livingstonei McNeill, 1926 Australia Mictyris longicarpus Latreille, 1806 Bay of Bengal to New Caledonia and Australia Mictyris occidentalis Unno, 2008 Australia(King Bay, Dampier Archipelago) Mictyris platycheles H. Milne-Edwards, 1852 Tasmania and Australia(Victoria to Queensland) Mictyris thailandensis Davie, Wisespongpand & Shih, 2013 Thailand
The predictable behaviour of these crabs has led them to be used in experiments in a form of billiard ball computer.
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