bivalve

The shell of a cockle is formed from calcium carbonate, so is inorganic (non-living). The cockle is a small, edible, marine bivalve mollusc.

The creature that lives in a Van Hyning's cockle is a pea crab. Pea crabs are small soft-bodied crabs that live as commensals inside the shells of bivalve mollusks like the Van Hyning's cockle. They feed on the host's food particles and detritus.

Cockatoos are birds and, like all birds, they are vertebrates because they have a spine and spinal cord, and an internal skeleton. They belong to the Phylum Chordata.

Mammals, birds, fish, reptiles and amphibians are all vertebrates.

The term "cockleshell" refers to the shell of a cockle, which is a type of marine bivalve mollusk. It can also be used figuratively to describe something small, weak, or fragile, suggesting vulnerability or insignificance.