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Phylum Arthropoda > Subphylum Crustacea > Class Malacostraca > Order Decapoda > Brachyurans
Stalk-eyed crabs
Superfamily Ocypodoidea
updated Dec 12

if you learn only 3 things about them ...
This group includes crabs usually found on sandy shores: fiddler crabs, soldier crabs, sand bubblers and ghost crabs.
They come out at low tide and cover the shore. Don't step on them!
They are very shy. To see them, wait quietly without moving.

Where seen? Crabs belonging to this family include some of the most commonly encountered on our shores during the day: fiddler crabs (Uca sp.), sand bubbler crabs (Scopimera sp.) and soldier crabs (Dotilla sp.). Others like the ghost crabs (Ocypode sp.) are only active at night.

Features: Members of the family Ocypodidae are distinguished by eyes on stalks, usually set close together. Some have very long stalks indeed, relative to their body size. These eye-stalks fold away into grooves on the body, so the crab can scramble into hiding places without breaking the stalks. Their bodies tend to be squarish, although some like sand bubbler crabs and soldier crabs have almost spherical bodies. "Ocy" means fast and "podi" foot in Greek. And indeed, most are fleet footed indeed!

What do they eat? The smaller members tend to feed on edible bits, sifting the sand or mud for them. Larger ones such as ghost crabs are scavengers and forage on the shores for the recently dead.

The Sentinel crab has super long eye stalks.
Pulau Hantu, May 05


The eye stalks of a ghost crab 'fold' away
into grooves at the side of its body.

Tanah Merah, Aug 09

Stalk-eyed crabs on Singapore shores





Superfamily Ocypodoidea 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)
***Tan, Leo W. H. & Ng, Peter K. L., 1988. A Guide to Seashore Life.
****Lim, S., P. Ng, L. Tan, & W. Y. Chin, 1994. Rhythm of the Sea: The Life and Times of Labrador Beach.

  Family Camptandriidae (previously in Ocypodidae)
  ***Baruna sp.
****Baruna minuta
(Mouthface crab)

***Ilyogynis sp. (Mud feeder crab)

  Family Dotillidae (previously Ocypodidae)
  Dotilla sp. soldier crabs with list of species recorded for Singapore

Ilyoplax
sp. semaphore crabs
*Ilyoplax delsmani
(White semaphore crab) (VU: Vulnerable)
Ilyoplax lingulata
Ilyoplax obliqua
(Tweedie's semaphore crab)
Ilyoplax orientalis
Ilyoplax punctata

Scopimera sp. sand bubbler crabs with list of species recorded for Singapore

**Shenius anomalum (Shen crab)

  Family Macrophthalmidae (previously Ocypodidae) with list of species recorded for Singapore

  Family Ocypodidae
  Ocypode ceratophthalmus (Horn-eyed ghost crab)
*Ocypode cordimanus
(Smooth-eye ghost crab) (VU: Vulnerable)

Uca sp. fiddler crabs see species page for list of species

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.
  • Lim, S., P. Ng, L. Tan, & W. Y. Chin, 1994. Rhythm of the Sea: The Life and Times of Labrador Beach. Division of Biology, School of Science, Nanyang Technological University & Department of Zoology, the National University of Singapore. 160 pp.
  • Wee Y.C. and Peter K. L. Ng. 1994. A First Look at Biodiversity in Singapore. National Council on the Environment. 163pp.
  • 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. Nature Society (Singapore). 285 pp.
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