Want to know what makes the sand balls?
Have you noticed these little balls on the beach at low tide? Often around a small hole, approx. 1cm in diameter? They are made by crabs, in this case the little Sand Bubbler Crab.
Image by vicnick08
The elusive Sand Bubbler Crab
Sand Bubbler Crabs are small crabs, around 1cm across the carapace (shell). The balls are there as a result of how they feed, filtering sand through their mouthparts, sifting out the detritus* and plankton**. Discarding the processed sand as pellets covering parts of the beach.
The crabs work radially (in a circle) from the entrance of their burrows, which they re-enter as the tide rises and washes away the pellets. In each burrow, the crab waits out the high tide in a bubble of air.
Plenty of other species of crab feed in a similar fashion. Sand Bubbler Crabs are very fast, keep your eye out for them.
Love where we live and co-exist with nature in our wildlife friendly biosphere with these tips:
- stay on the designated walkway and out of the dunes and bush
- keep your dogs on a lead and pick up after them
- bin your rubbish to keep our Sunshine Coast clean and litter free.
Macquarie dictionary definition:
*detritus
noun 1. particles of rock or other material worn or broken away from a mass, as by the action of water or glacial ice. 2. any disintegrated material; debris.
**plankton
noun the mass of small animal and plant organisms that float or drift in the water, especially at or near the surface: many fish survive by eating plankton; planktons are important to marine life.