''Mictyris'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of brightly coloured
crab
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...
s, placed in its own
taxonomical
In biology, taxonomy () is the scientific study of naming, defining ( circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon) and these groups are given ...
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
, the Mictyridae.
It inhabits the central
Indo-West Pacific
The Indo-Pacific is a vast biogeographic region of Earth.
In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...
region. These crabs congregate on
mud flat
Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal fl ...
s or
beach
A beach is a landform alongside a body of water which consists of loose particles. The particles composing a beach are typically made from rock, such as sand, gravel, shingle, pebbles, etc., or biological sources, such as mollusc shel ...
es in groups of a few thousand, and filter sand or mud for microscopic organisms. They congregate during
low tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another.
Tide tables can ...
, 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
A corkscrew is a tool for drawing corks from wine bottles and other household bottles that may be sealed with corks. In its traditional form, a corkscrew simply consists of a pointed metallic helix (often called the "worm") attached to a hand ...
pattern, leaving many small round pellets of sand behind them.
Species
The genus contains eight species:
The predictable behaviour of these crabs has led them to be used in experiments in a form of
billiard ball computer
A billiard-ball computer, a type of conservative logic circuit, is an idealized model of a reversible mechanical computer based on Newtonian dynamics, proposed in 1982 by Edward Fredkin and Tommaso Toffoli. Instead of using electronic signals li ...
.
References
External links
*
Ocypodoidea
{{Crab-stub
Crustaceans