The fins are supported by the dorsal rays. There are two types of rays: branched and unbranched.

Branched rays are the outer skeleton of the bony fins of fish. The upper part of the ray is divided into individual rays and resembles a tassel. The rays are soft.

The peripheral parts of the fins are supported by thin rays of horn-like or bony tissue. The muscles that stretch the blade are attached to the base of these rays.

The number of rays on the fins, especially on the dorsal and anal fins, is a species characteristic. The pelvic fins usually have more than 7 rays. The anal fin has less than 10 rays.