Rays (Rajiformes) are found in most of the world’s oceans. Rays are cartilaginous fish, and the smaller ones are also known as “dangdang fish”. One hundred million years ago, rays and sharks were the same species, but they adapted to life under the sea by hiding their bodies in the sand and evolved into what you see now. The flying Wenyao fish described in the Classic of Mountains and Seas actually refers to the ray we see today. When they hunt, they mainly rely on smell to get food. They have a flat body, a head directly connected to the body, without a neck They have a long tail and two eyes on the dark back. Their mouths and gill rows for breathing are on their bellies, looking as if they are smiling at us.