seen? This inconspicous little crab with eyes on super
long stalks are sometimes seen on soft silty and muddy shores such
as swimming lagoons. It builds distinctive holes which are either
rectangular or oval and seldom circular.
Features: Body width 0.5-1cm.
Body is flattened, squarish or somewhat rectangular. The eye stalks
are long and in some species can even extend outside the sides of
the body. This feature probably gave them their common name. Both
pincers of equal size.
Sometimes confused with fiddler crabs
(Uca spp.). Sentinel crabs do not have one enlarged pincer
like the fiddler crabs. Sentinel crabs are also not colourful, usually
drab brown with darker mottling. Here's more on how
to tell apart small crabs with long eye stalks.
What does it eat? It feeds on
detritus and small worms.
Pulau Hantu, May 05
on a worm.
Pasir Ris, Jan 09
Pulau Hantu, Jun 09
moulted! Moult has transparent eyes.
Pasir Ris, Dec 08
long eye stalks!
Sisters Island, May 12
Pulau Semakau, Sep 05
Pasir RIs Park, Jul 08
crabs on Singapore shores
Macrophthalmidae recorded for Singapore
Wee Y.C. and Peter K. L. Ng. 1994. A First Look at Biodiversity
in red are those listed among the threatened
animals of Singapore from Davison, G.W. H. and P. K. L. Ng
and Ho Hua Chew, 2008. The Singapore Red Data Book: Threatened
plants and animals of Singapore.
**from Ng, Peter K. L. & N. Sivasothi, 1999. A Guide to the Mangroves
of Singapore II (Animal Diversity)
Macrophthalmidae (previously Ocypodidae)
Macrophthalmus brevis=Macrophthalmus dilatatus
**Macrophthalmus crinitus (Little sentinel crab)
Macrophthalmus latreilllei (Latreille's sentinel crab)