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Anadara ovalis
Image courtesy of the World Register of Marine Species (WoRMS), via the Natural History Museum, Rotterdam through the Creative Commons, CC BY-NC-SA 3.0 License
Anadara ovalis
Taxonomic Group: Mollusks-Bivalves
Common name: BLOOD ARK


Anadara ovalis is a marine bivalve, commonly known as the Blood Ark. It has a thick, strongly ribbed shell, and its blood contains hemoglobin (rare in bivalves), which makes it bright red. It is native to the Northwest Atlantic, being rare in Massachusetts Bay, but common in coastal waters from Cape Cod to the Gulf of Mexico. A dead shell was found in 1967 at Coyote Point, on San Francisco Bay, but no subsequent live or dead specimens have been found. It usually settles on mud or sand, but will occasionally attach to rocks and shells with byssus threads. It can survive at polyhaline to euhaline salinities (18-35 PSU). There are no reported impacts for this species.

*Beyond its native range, this species is not established in North America.

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Fofonoff PW, Ruiz GM, Steves B, Simkanin C, & Carlton JT (2018)
National Exotic Marine and Estuarine Species Information System.
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Marine Invasions Lab
Smithsonian Environmental Research Center

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