Tags: clam | Cyrenobatissa subsulcata | shell

The Cyrenobatissa subsulcata is the largest known clam, its shell is up to 8 cm in length and over 7 cm in height, hence the name. It features a blackish-brown color, slightly round ventral margin, and a tint of yellow in its interior. It used to be found at the convergence of Danshui River and Keelung River and the downstream estuary, where brackish water is produced by the mixing of fresh water and sea water. It has already become extinct.