Anodontia alba
The Buttercup Lucine shell is a dull white with an interior that is white to butter yellow. The shell may grow to 2 inches.
The bivalve lives in soft mud or sand in areas of low nutrients, low oxygen and high sulfides in waters 3 to 300 feet deep. It has a very long foot that may be 6 times as long as the shell. It uses the foot to construct a mucus-lined tube in the sand. Through this tube it draws in water and food. After filtering out the nutrients, the wastes and water are then expelled through a long siphon. The siphon is unusual in that it retracts by turning itself inside out. The Buttercup Lucine also hosts symbiotic sulfur-oxidizing bacteria in their gills providing additional sustenance.
Live shells should never be taken from any Florida State Park.