Macrophthalmus pacificus

Macrophthalmus pacificus is a species of sentinel crab found widely across the Indo-West Pacific Ocean, including India, Japan, Malaysia, New Guinea, Solomon Islands, and northern Australia.^[2]

Macrophthalmus pacificus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Malacostraca
Order:	Decapoda
Suborder:	Pleocyemata
Infraorder:	Brachyura
Family:	Macrophthalmidae
Genus:	Macrophthalmus
Subgenus:	Mareotis
Species:	M. pacificus
Binomial name
Macrophthalmus pacificus Dana, 1851
Synonyms[1]
Macrophthalmus bicarinatus Heller, 1862

In Australia it is found in the north from northern New South Wales to around Exmouth in Western Australia.^[1] 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.^[3] It is often found feeding in shallow still water, and in soft mud.^[4]: 2 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.^[3] The carapace is smooth and shiny, up to around 25 mm across.^[5]

A synonym of Macrophthalmus pacificus is Macrophthalmus bicarinatus.^[1]