''Macrophthalmus pacificus'' is a species of sentinel crab found widely across the Indo-West Pacific Ocean, including India,

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

, Malaysia, New Guinea, Solomon Islands, and northern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. In Australia it is found in the north from northern New South Wales to around Exmouth in Western Australia. ''M. pacificus'' lives in mud in tidal zones of river mouths' adjacent mangrove forests in low tide areas. The claws of adult males are sky blue. It is often found feeding in shallow still water, and in soft mud. The upper claw of males has a tooth on the upper claw (dactyl). Like other ''Macrophthalmus'' species, the claws of the male are larger than those of the female. The carapace is smooth and shiny, up to around 25 mm across. A synonym of ''Macrophthalmus pacificus'' is ''Macrophthalmus bicarinatus''. ''

References

{{Taxonbar, from=Q13805959 Ocypodoidea Crustaceans described in 1851 Taxa named by James Dwight Dana