The casing that surrounds the egg or eggs of a shark, skate or chimaera
Of the approximately 400 species of sharks, about 60% bear their young live; the other 40% in common with all skates and chimaera lay eggs. The egg case has tendrils that allow it to attach to a substrate such as corals, seaweed or the ocean bottom. In some shark species the egg cases are pushed into the bottom or into crevices between or under rocks.
