Mole Crab

Mole Crab

The Mole Crab or Sand Bug Emerita talpoida lives on ( or rather in ) ocean beaches, burrowing in the surf zone, and at times free swimming. It is totally harmless and grows to 1.5". These odd and somewhat comical little creatures seem to do everything in reverse - they dig backwards, walk backwards, and swim backwards. Fishermen dig them up for bait.

Mole Crab
Mole Crab

Sand Bugs filter feed with their long feathery antennas, which are withdrawn into protective sheaths when not in use. Not the long eye stalks that allow the animal to remain completely buried, and the short powerful limbs. They are unable to walk in any conventional sense, but are powerful diggers, and also surprisingly swift ( if somewhat random ) swimmers.


aluminum tanks

Scuba tanks are made out of steel or aluminum. Aluminum is cheaper and has somewhat better corrosion resistance, but steel is stronger. The "standard" modern scuba cylinder is the aluminum "80", which actually holds about 77 cubic feet of air at its rated pressure of 3000 psi. This type of tank has probably caught on because for an average-sized person with reasonably good breathing skills, this size is just big enough to cover your allowable no-decompression bottom time and no more. For smaller people, 63 cubic foot aluminum tanks are available, while for larger folks there are choices as big as 120 cuft.

Printed from njscuba.net