The valves of Noah’s ark are covered with fine sculptured ribs. They are brown or greyish red and stripped with light zigzag stripes. They can reach maximum up to 10 cm (measured by the longest base) and 6 dkg. Average types have cca 2 dkg and 6 cm.
Noah’s ark lives along the entire coast of the Adriatic, but not everywhere like mussel. There are places where numerous dense clusters can be found , while at other areas it is almost unknown. It commonly inhabits hard sufaces but it’s also found on the gravelly –shelled bottom provided that there are stones. It’s always attached to the surface at the depth between 1 and 10 m. The largest clusters in our part of the Adriatic are to be found along the coast of Istria, around Umag and Novigrad, in Pašman passage, Mali ston bay and other localities.
Kunjka is to be looked for on positions with strong sea current but at the same time protected from the strong impact of the sea. Similar to other shells, it feeds by filtrating salt water, taking the plankton and other small particles.