Dosinia anus

Dosinia anus, common names the ringed dosinia, coarse dosinia, coarse biscuit shell, and Tuangi-haruru in the Māori language, is a species of saltwater clam, a marine bivalve mollusc in the family Veneridae, the venus clams. This species is common to both of the main islands of New Zealand, where it is the largest and heaviest species in the genus, occasionally exceeding 80mm in diameter. It buries itself in clean fine sandy substrata, sub-tidally down to 15m deep. An investigation into a potential surf clam fishery found this species to be the most abundant 'surf clam' (an informal grouping based on habitat) in the North Island, being replaced by members of the Mactridae in more southerly latitudes.