The Portuguese oyster, Crassostrea angulata, is a species of oyster found in the southwest Iberian Peninsula, closely related to the Pacific oyster. Although first identified as a native European species, genetic studies<ref, Boudry P et al. 1998. Differentiation between populations of the Portuguese oyster, Crassostrea angulata (Lamark) and the Pacific oyster, Crassostrea gigas (Thunberg), revealed by mtDNA RFLP analysis. Journal of Experimental Marine Biology and Ecology.></ref> have suggested the Portuguese oyster originated from the Pacific coast of Asia and was introduced to Europe by Portuguese trading ships in the 16th century. The species is usually found in coastal river mouths and estuaries.
Prior to decimation by iridoviral disease in 1969, C. angulata was extensively cultivated in France and Portugal as part of the edible oyster industry. The Pacific oyster, which is more resistant to the disease, was introduced in the 1970s and has since replaced C. angulata as the main commercial species. Currently, the Portuguese oyster is not cultured commercially.
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