Crassostrea madrasensis

Magallana bilineata, commonly known as the Philippine cupped oyster or slipper oyster, is an economically important species of true oyster found abundantly in the western Pacific Ocean, from the Philippines to Tonga and Fiji. They grow attached to hard objects in brackish shallow intertidal or subtidal waters, at depths of 0 to 300 metres (0 to 984 ft). They are cultured extensively in the Philippines, where annual landings can range from 11,700 to 18,300 tons. They are known as talaba or talabang tsinelas ('slipper oyster') in Filipino to distinguish them from talabang kukong kabayo ('horse-hoof oyster', Saccostrea malabonensis)