Black abalone

The coloration is dark brown, dark green, dark blue or almost black. The silvery interior of the shell shows a pale pinkish and greenish iridescence. The exterior of the shell is smoother than most abalones, or may have low obsolete coarse spiral lirae and lines of growth. The shell is oval, evenly convex, the two sides equally curved. The back of the shell is regularly convex, with little algal growth. The shell is not carinated at the row of holes. The spire is near the margin. The cavity of the spire is minute, concealed or nearly so. The muscle scar is generally not distinct. There are usually five to seven small, open respiratory holes, or pores, along the left side of the shell and the rims of the holes are flush with the rest of the shell. These holes collectively make up what is known as the selenizone which form as the shell grows. The columellar plate is not truncate below, sloping inward, its face concave. The rear of the shell is spiralled, and the mantle, foot and tentacles are black. The interior of the shell is pearly with pink and green iridescence. The black abalone's shell length can reach a maximum of 20 cm (7.9 in), being typically 10–14 cm (3.9–5.5 in) long. In the living animal, the tentacles on the epipodium, the mantle, and the foot are black.