ABSTRACT
The shell of Tiostrea chilensis is oval or subcircular in outline, and the lower, or left, valve is cupped and attached to a substrate. The smaller right valve is nearly flat. Maximum size is about 8.7 cm. T. chilensis lives naturally attached to rocks or shells on a stony, sand, or hard mud bottom. At times the oysters grow attached to each other, forming irregular clusters. Larval development is completed within the mantle cavity. Larvae are 416 to 514 μm in length when released,6 after about 50 d of incubation. However, growth rate has been increased 50 to 60% with off-bottom culture. The fishery historically has been centered in the Chiloe region. Oysters generally were collected by hand from rocks exposed at low tide or by divers from submerged banks. Overfishing has been cited as a factor contributory to the demise of the oyster fishery.
