Appearance
Molas develop their truncated, bullet-like shape because of their tail fin. The tail fin never grows but folds into itself as the fish matures, which creates a rounded rudder called a clavus. Mola in Latin means "millstone" and describes the ocean sunfish's somewhat circular, flattened shape. They are a silvery colour and have a rough skin texture.
Molas are the heaviest of all the extant bony fishes: large specimens reach 4.3 m (14 ft) vertically and 3 m (10 ft) horizontally, and can weigh over 2,700 kg (6,000 lbs).
Molas inhabit temperate and tropical oceans around the world. They are frequently seen basking in the sun near the surface and are often mistaken for sharks when their huge dorsal fins emerge above the water. Their teeth are fused into a beak-like structure, and they are unable to fully close their relatively small mouths.