The Mola mola, or ocean sunfish, is the heaviest bony fish in the world, reaching up to 2,200 kg. It has a distinctive flattened body and long dorsal and anal fins. Mola molas are found in temperate and tropical oceans, often basking on the surface to soak up the sun's warmth.

The Mola mola, commonly known as the ocean sunfish, is native to temperate and tropical waters worldwide. It is found in both the Atlantic and Pacific Oceans, with notable populations in the Mediterranean Sea and around the southern coasts of Africa, Australia, and South America. Key regions include the North Atlantic (from Newfoundland and Norway to the Mediterranean and West Africa) and the North Pacific (from Alaska and Russia to Chile and New Zealand).

The ocean sunfish inhabits pelagic waters, often found in open ocean environments far from the coast. They prefer water temperatures ranging from 10°C to 23°C but can sometimes be found in slightly warmer or cooler waters. Sunfish are often found at depths of up to 600 meters but are more commonly observed near the surface, basking in the sun.

Mola mola occupies a unique ecological niche as a large, slow-moving fish that feeds primarily on gelatinous zooplankton, such as jellyfish, as well as small fish and plankton. This diet allows them to play a role in controlling jellyfish populations. They are known for their distinctive flattened bodies and large dorsal and anal fins, which assist in their slow but efficient swimming style.