There are seven different species of bivalve mollusks that Cloudy Bay Clams harvest, found in various locations around the New Zealand coastline. Each species is distributed over a distinct depth zone between low water and 10 meters.

Maximum size of all species varies with latitude, and are generally larger in South Island.

Large Trough Shell (Mactra murchisoni)
More abundant in South Island; occurs in 4-8 m depth range; maximum size 63-102 mm; Shell larger and more angular than M. discors; white shell with pale straw coloured periostracum, particularly prominent on new shell growth;

Trough Shell (Mactra discors)
More abundant in South Island; occurs in 3-7 m depth range; maximum size 63-95 mm; Similar to M. murchisoni but shell more solid, smaller, rounder and more inflated; shell white but appears brown as is generally completely covered in dark brown periostracum;

Triangle or Diamond Shell (Spisula aequilater)
More abundant in the South Island; occurs in 3-5 m depth range; maximum size 39-74 mm; solid, triangle-shaped inflated shell; shell white in adults, violet in juveniles;

Deepwater Tuatua (Pahpies donacina)
More abundant in South Island; occurs in low tide-4m depth range; maximum size 73-109 mm; solid shell, inequal triangle shape, rounded posteriorly; shell cream colour; adductor muscle cream; (the shell of the tuatua P. subtriangulata, generally found in shallower water, is similar but smaller, and differentiated by more angular profile, grey shell colour, as well as by the blue adductor muscle);

Ringed Dosinia or Moon Shell (Dosinia anus)
More common in North Island; occurs in 5-10 m depth range; maximum size 58-82 mm; solid heavy shell, almost circular, with closely spaced strongly developed concentric ridges; shell pink-brown colour; flesh light apricot colour;

Silky Dosinia (Dosinia subrosea)
More common in North Island, it occurs on more sheltered beaches and buries deeper than D.anus. It occurs in 6-10 m depth range; shell similar to but smaller than D. anus; maximum size 41-68 mm; solid shell, more ovate and inflated than D. anus; fine, flat-topped concentric ridges on shell give silky appearance and texture; shell white to yellowish colour;

Frilled Venus Shell (Bassina yatei)
Occurs in 6-9 m depth range; maximum size 48-88 mm; shell solid, ovate/subquadrate, with concentric lamellae, often frilled or spinose posteriorly; shell creamy white colour;