Sentinel
crab
Macrophthalmus sp.
Family Macrophthalmidae
updated
Dec 2019
Where
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 |
Pulau Hantu, May 19
Photo shared by Jianlin Liu on facebook. |
|
Nibbling
on a worm.
Pasir Ris, Jan 09
|
Squarish
burrow opening.
Pulau Hantu, Jun 09
|
Just
moulted! Moult has transparent eyes.
Pasir Ris, Dec 08
|
Sentinel
crabs on Singapore shores |
Other sightings on Singapore shores |
East Coast-Marina Bay, Jan 21
Photo shared by Vincent Choo on facebook. |
|
St John's Island, Jan 13
Photo shared by Loh Kok Sheng on flickr. |
Kusu Island, Sep 10
Photo shared by Loh Kok Sheng on flickr. |
Beting Bemban Besar, Aug 18
Photo shared by Liz Lim on facebook. |
Terumbu Pempang Laut, Aug 21
Photo shared by Vincent Choo on facebook. |
|
Family
Macrophthalmidae recorded for Singapore
from
Wee Y.C. and Peter K. L. Ng. 1994. A First Look at Biodiversity
in Singapore
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)
+from The Biodiversity of Singapore, Lee Kong Chian Natural History Museum.
|
Family
Macrophthalmidae (previously Ocypodidae) |
|
+Chaenostoma cf. boscii
+Ilyograpsus sp.
Ilyograpsus
paludicola
Macrophthalmus boscii
Macrophthalmus brevis=Macrophthalmus dilatatus
Macrophthalmus convexus
Macrophthalmus crassipes
**Macrophthalmus crinitus (Little sentinel crab)
Macrophthalmus erato
Macrophthalmus japonicus
Macrophthalmus latreilllei (Latreille's sentinel crab)
+Macrophthalmus milloti
Macrophthalmus pacificus
Macrophthalmus parvimanus
Macrophthalmus telescopicus
Macrophthalmus travancorensis |
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Links
References
- Ng, Peter
K. L. and Daniele Guinot and Peter J. F. Davie, 2008. Systema
Brachyurorum: Part 1. An annotated checklist of extant Brachyuran
crabs of the world. The Raffles Bulletin of Zoology. Supplement
No. 17, 31 Jan 2008. 286 pp.
- Jones Diana
S. and Gary J. Morgan, 2002. A Field Guide to Crustaceans of
Australian Waters. Reed New Holland. 224 pp.
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