The fastest marine animal is the black marlin, which can swim at speeds exceeding 82 miles per hour (132 kilometers per hour). This impressive speed makes it one of the fastest fish in the ocean and allows it to evade predators and catch prey effectively. Black marlins are known for their strong, muscular bodies and are often sought after in sport fishing due to their speed and fighting ability. Their remarkable agility in the water contributes to their reputation as one of the ocean's top predators and highlights the incredible adaptations of marine life.