''Achaeus japonicus'', sometimes known as the orang-utan crab, is a
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 ...
of the
family Inachidae
Inachidae is a family of crabs, containing 39 genera:
*'' Achaeopsis'' Stimpson, 1857
*'' Achaeus'' Leach, 1815
*'' Anisonotus'' A. Milne-Edwards, 1879
*'' Anomalothir'' Miers, 1879
*'' Bothromaia'' Williams & Moffitt, 1991
*'' Calypsachaeus'' ...
(spider crabs or
decorator crabs
Decorator crabs are crabs of several different species, belonging to the superfamily Majoidea (not all of which are decorators), that use materials from their environment to hide from, or ward off, predators. They decorate themselves by sticking ...
) which can be observed in tropical waters of the central Indo-Pacific.
With a
carapace
A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...
of only about in diameter, it has relatively long arms, which are thickly covered with fine hairs, red or reddish brown in colour, and often laden with small bits of debris for further camouflage. It is frequently, but not always, found in association with the bubble coral ''
Plerogyra sinuosa
''Plerogyra sinuosa'' is a jelly-like species of the phylum Cnidaria. It is commonly called "bubble coral" due to its bubbly appearance. The "bubbles" are grape-sized which increase their surface area according to the amount of light available: th ...
''.
Humann and DeLoach
[ classify the orang-utan crab as ''"Oncinopus sp. 1"'' and assert it was "formerly classified" as ''Achaeus japonicus,'' though they describe their own genus identification as "tentative."
]
References
External links
*
* http://www.marinespecies.org/aphia.php?p=taxdetails&id=441846
*
Majoidea
Crustaceans described in 1839
{{Crab-stub