Bumphead Sunfish

The Giant Sunfish, scientifically known as Mola alexandrini, is a fascinating marine creature that belongs to the ocean sunfish family, Molidae. This species inhabits the world's oceans except for the polar regions, with a notable presence in the Southern Hemisphere and tropical and temperate seas. The fish gained recognition when a specimen weighing 2,744 kilograms (6,049 pounds) was discovered near the Azores in 2021, making it the heaviest bony fish ever recorded.

Mola alexandrini, also referred to by names such as the southern sunfish or bumphead sunfish, can grow up to 3.3 meters (11 feet) in length. The fish sports a unique body shape: flat, round, and distinguished by large dorsal and anal fins used for propulsion. Its skin is rough and covered with small, rectangular scales that are brown or gray, sometimes with pale patches, which turn white upon death. With a rigid and leathery texture, it lacks caudal bones, ribs, and pelvic fins, yet possesses fused vertebrae.

This species is characterized by distinct physical features like a noticeable bump on its head and chin, as well as a rounded clavus, an extension of its dorsal and anal fins. As the fish mature, various ossicles—a type of bone-like structure—develop, adding to its large body structure.

Mola alexandrini thrives in water temperatures ranging from 16.8°C to 25.6°C (62.24°F to 78.08°F), preferring the open ocean and often basking near the surface to regulate its body after deep dives. These dives, typically during the day, bring them to depths of 1 to 480 meters. At night, they tend to remain in warmer, shallower waters.

The digestion system of these fish mainly consists of jellyfish, but they are known to consume other low-nutritional organisms like brittle stars, small fish, and plankton. Despite their massive size, they can be preyed upon by few species such as tiger sharks and orcas. However, attacks are uncommon, possibly because their gelatinous body isn't a preferred meal.

The reproductive capability of the Giant Sunfish is quite extraordinary; a single female can produce up to 300 million eggs in a spawning season, though the exact timing in natural environments remains uncertain. Their lifecycle begins with larvae as tiny as 1.42 mm, eventually growing to juveniles that are 305–750 mm in length before reaching adulthood.

Mola alexandrini holds significance in marine ecosystems, affecting local food webs due to its feeding habits. Although only a few fisheries target them, they are appreciated in tourism, providing spectacular shows for divers and snorkelers in places like the Galapagos Islands and the Mediterranean's Alboran Coast. In regions such as 🇮🇩 Indonesia, occasional captures are made, and these fish are typically released or used locally.