According to the Guinness World Records, the heaviest Mola mola ever caught on record weighed 5,070 pounds (2,295 kilograms). This giant sunfish was caught off the coast of Kamogawa, Chiba Prefecture, Japan in 1996.
It is important to note that these massive weights are quite rare, and most mola fish are smaller in size. The average weight range for ocean sunfish is typically between 1,000 to 2,000 pounds (454 to 907 kilograms), with larger individuals occasionally exceeding these ranges.
The enormous size of mola fish is attributed to several factors, including their diet, habitat preferences, and slow metabolism. They primarily feed on jellyfish, which are low in nutritional value, so they must consume large quantities of food to obtain sufficient energy. Additionally, mola fish inhabit open ocean environments and are not constrained by structural limitations, allowing them to grow to such impressive sizes. Their slow metabolism also contributes to their ability to accumulate massive amounts of body fat, which provides insulation and buoyancy.