|SAN SALVADOR BIVALVES
Family Ostreidae (Triassic to Holocene) - the oysters are filter-feeding, epifaunal, hard substrate encrusters that sometimes form reefs. They occupy tropical to temperate estuarine and shallow-water marine settings.
Dendostrea frons (Lamarck, 1819) - exterior (top) & interior (middle) & lateral view (bottom) of a left valve of the frond oyster, 5.9 cm across at its widest. Frond oyster shells vary in shape, which is dictated by the nature of the encrusted substrate - usually gorgonians ("soft corals"). This individual had encrusted an upright gorgonian. The three coiled structures on the shell's exterior are encrusting worm tubes.