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| Phylum Arthropoda > Subphylum Crustacea > Class Malacostraca > Order Decapoda > Brachyurans > Superfamily Ocypodoidea |
| Ghost
crabs Ocypode sp. Family Ocypodidae updated Oct 08
Where seen? Ghost crabs are common on many of our shores. Yet, these speedy crabs are almost impossible to spot. They probably got their common name because they are active only at night, and they move so swiftly over the sand that you usually literally only get a fleeting glimpse of them. However, their burrows are quite commonly seen, high up on the shore. Features: Body width to 6-8cm. Ghost crabs are well adapted for life out of water and are among the few marine creatures that roam the beaches at low tide. They can stay for a long time away from the sea because they can absorb water from the wet sand through special hairs on the base of their legs by capillary action. Ghost crabs live in burrows that they dig high up on the shore away from the water. It is said that when tunneling out their burrow, they carry sand to about 50-100 cm away from their burrow entrance, then toss the sand as far as they can. This behaviour probably explains the typical "spray" pattern of sand around their burrow. Their burrows go quite deep. So please don't try to dig them up. Speedy Ghosts: Ghost crabs can really run fast! As suggested by their scientific name ("Ocy" means swift and "podi" foot in Greek). They literally fly over the sand and their movement has been described as a small leaf blowing over the sand surface. In fact, they may be among the fastest land creatures, moving at 100 bodylengths per second. In comparison, the cockroach does 50 bodylengths while the cheetah does a sluggish 10 bodylengths. Ghost crabs are only beaten by tiger beetles which do 171 body lengths when they are really scared. Being fast moving creatures, Ghost crabs have excellent eyesight to see where they are going. Their eyes are on stalks. What do they eat? Ghost crabs are scavengers, foraging at night for any dead creatures left behind on the shore at low tide. They may also hunt small animals and clams and snails near the water's edge. At night, they have been seen foraging on the wet intertidal near the mid-water mark. Role in the habitat: Ghost crabs deal with the dead in their habitat. They are in turn eaten by many animals higher up in the food chain. Status and threats: The Smooth-eyed ghost crab (Ocypode cordimanus) is listed among the threatened animals of Singapore. It has smooth oval eyes and is found further inland than the more commonly encountered Horn-eyed ghost crab (Ocypode cerathophthalmus). Like other creatures of the intertidal zone, Ghost crabs are affected by human activities such as reclamation and pollution. Trampling by careless visitors also have an impact on local populations. |
 The Horn-eyed ghost crab is commonly seen at night. Changi, Jun 05  Eyes fold away into a slot on the body. St. John's Island, Jan 04  Eating another crab! Pulau Hantu, Nov 03  Large burrows built near the high water mark. Changi, Apr 05 |
They only seen at night. But the large holes to their
burrows are commonly seen on sandy shores near the high
water mark.
Their burrows are deep. Don't try to dig them up. Links
References
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