Sand bubbler crab
From Wikipedia, the free encyclopedia
 |
This crab article is a stub. You can help Wikipedia by expanding it. |
| Sand bubbler crabs | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 Scopimera globosa, making sand grains.
|
||||||||||||||||
| Scientific classification | ||||||||||||||||
|
Sand bubbler crabs are nocturnal crabs of the genus Scopimera. As the low tide sets, thousands emerge from their burrows beneath the sand. They begin feeding on the beach by collecting sand and quickly sifting through it in search off microscopic material (detritus) between each grain. This process inadvertently cleans the sand. When the sand is stripped of any nutrition, the crabs gather it into a sphere and toss it over their backs.
In Australia, these crabs have been observed feeding for about two hours after sunset. After feeding, Australian sand bubbler crabs appear to become lethargic and can be found resting on the surface of the sand. It is during this time that sand bubbler crabs are particularly vulnerable to threats. For example, if threatened after feeding, sand bubbler crabs remain immobile and do not retreat beneath the sand to safety. This is unusual behaviour because these crabs do return to their burrows when threatened at any other time. The sand bubbler crabs carve grooves into the sand, and quickly sift out detritus with their mouthparts, leaving behind rolled up balls of sand. The crabs return to their burrows when threatened.
Several species of sand bubbler crab occur around the Indian and Pacific Oceans, from East Africa to Hawaii, including much of Asia and Australia. Sand bubbler crabs are still common in inner city areas such as Jawbone Marine Sanctuary in Williamstown, Victoria.
