Margintail conger

Found burrowed into soft mud or sand bottoms, in shallower waters, of the continental shelf during the day, foraging for food at night, and has been observed at night on the surface of the ocean.
They feed nocturnally on crustaceans and small fish.
Widespread - Western Atlantic, Caribbean

Garden Eels rise up in the sand halfway their body length waving in the sand feeding on plankton.
When approached they slide back into their holes.