Clam Shrimps are tiny bivalved crustaceans. They look like molluscs but can swim.
Clam Shrimps can be found in rock pools, ponds, dams, lakes, etc.
In rock pools like the ones on Shamash Point the Clam Shrimps breed once during a wet period. Eggs will hatch in the next wet period following a dry period. I've only ever seen them once, in a pool on an isolated pagoda at Shamash Point. The other pools were empty.