The Tuatua lives in crowded beds on open beaches exposed to surf.
It is smooth, and wedge shaped, with a thick shell. It lives at
or below the low tide level and uses its strong foot to dig in
quickly if a wave washes it out of the sand - something that happens
often as they live just below the surface of the sand. On west
coast beaches they form dense, but localised beds which migrate
as a group up and down the shore. This makes them difficult to
measure as the beds don't remain in one place from one survey
to the next and even finding them can be a problem.
Tuatua are found around most of the New Zealand coast, and the
east coast specimens are generally smaller than those of the west
Tuatua grow to about 60-mm in shell length and, like other bivalves,
filter the sea water for planktonic organisms through two very
Tuatua are greatly prized, and have a sweeter flesh than the larger
Toheroa. Many of the Maori shell middens are testimony to the
long standing enjoyment of these shellfish by New Zealanders.