About Lesson
Structure of fins
- The fins constitute the major propulsive/locomotory organs in fishes.
- These are either folds of skin or projections from the body surface.
- The fins are supported by fin rays.
- The supporting rays may be bony, cartilaginous, fibrous, or horny.
- There are mainly two types of fins in fishes: 1 . Unpaired or median fins and 2. paired fins.
- The unpaired or median fins include a dorsal fin on the back, an anal fin on the ventral side behind the vent, and a caudal fin at the end of the tail.
- The paired fins are the pectorals and pelvic or ventrals corresponding to the fore and hindlimbsb of the terrestrial vertebrates.