''Acanthonyx dentatus'', the toothed decorator crab, is a
species of
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 ...
in 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'' ...
.
Distribution
The toothed decorator crab is known around the southern African coast from
Cape Columbine
Cape Columbine is well known for its lighthouse, the last staffed lighthouse built on the South African coast The Cape Columbine Lighthouse was commissioned on October 1, 1936. Both the headland and lighthouse derive their name from the barque C ...
to
Richards Bay subtidally to .
It is also known from the
Red Sea.
Description
The toothed decorator crab may grow to across. It is usually a well camouflaged crab,
decorating its carapace with
hydroids and
seaweed
Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...
s, offering
camouflage and also
defence, since hydroids sting and many seaweeds are chemically noxious. Its carapace is teardrop-shaped with two sharp spines projecting forwards between its eyes. There are two marginal spines on its carapace. It has stubby legs. It is a vivid pink-red to a dull brown in colour.
Ecology
Vividly coloured when recently moulted, these animals are commonly found taking refuge among groups of
striped anemones. The crabs use the anemones' habit of shooting sticky defensive threads through their body walls for their own defence.
References
{{Taxonbar, from=Q4671998
Majoidea
Crustaceans described in 1834
Taxa named by Henri Milne-Edwards