Mahi develops tremendously quickly and are like the rabbits of the sea. They might end up being the fastest-growing wild fish ever discovered. These fish have been proven to grow up to four feet and 40 pounds in just a single year. While being kept in captivity, average growth is about 1.3 to 2.7 inches per week.

At five months, they are adults in the wild and can weigh 5 to 6 pounds. Mahi begins to reproduce at a young age. By three to five months of life or 22 inches in length, all mahi are capable of reproducing.

Most weigh more than 20 pounds at one year. Most three-year-olds weigh more than 30 pounds. Fish rarely survive past their fourth year. The fish breed every four to six weeks as they reach maturity, dispersing roughly 400,000 eggs.The tiny eggs—about the size of a pinhead—hatch out in 60 hours or so. The tiny fish begin to grow right away, gaining one to one and a half inches every month. Due to their rapid growth, they must continually eat, and they frequently bite quite viciously.

Mahi forage throughout the entire water column and are opportunistic feeders. From paper nautilus to flying fish (malolo), they consume a wide variety of foods. Additionally, they eat both during the day and at night. Mahi eat about 5.6 percent of their body weight each day on average. The most voracious fish are small ones, which can consume up to 19.8% of their body weight, while the stomach contents of giant bulls can sometimes include up to 10% of the body weight of the fish.