Panama Pearl Oyster Shell, Pinctada mazatlanica

Panama Pearl Oyster Shell, Pictada mazatlanica. Shell collected from a tidal pool at Km 17, El Tule, Baja California Sur, February 2018. Size: 4.4 cm (1.7 inches) x 4.5 cm (1.8 inches).

The Panama Pearl Oyster, Pictada mazatlanica (Hanley, 1856), is a bivalve mollusk that is a member of the Pearl Oysters of the Pteridae Family. They are known in Mexico as ostra perifera panamena, ostra perlera vidua and la madre perla calafia. The shell has a disk-like appearance, being round and flattened. Both valves are similar in shape, but the lower valve has a notch for the byssus which is utilized to attach to the substrate. The external surface is scaly. The exterior of the shell is a mix of yellowish brown, and greenish gray regions specked with white and the interior is nacreous with a dark gray or black margin. The Panama Pearl Oyster reach a maximum of 15 cm (5.9 inches) in length and 15 cm (5.9 inches) in height.

Panama Pearl Oysters are found attached to hard surfaces in the intertidal zone to depths up to 24 m (80 feet). They are found throughout the Sea of Cortez and south to Peru including the Galapagos and Revillagigedo Islands; they are absent from along the West Coast of Baja.