Arapaimas are apex predators in their environment, preying on a variety of other fish, crustaceans, and even small land animals that come too close to the water's edge. They possess a specialized feeding mechanism, employing a sudden and powerful suction to capture prey. This feeding behavior, combined with their size and strength, makes the arapaima a formidable hunter. Additionally, their scales are incredibly tough, providing protection against attacks from other predators and even human-made threats.

These fish have a fascinating life cycle, with a breeding season that coincides with the Amazon's wet season. Arapaimas build nests in the sandy bottoms of floodplain lakes and rivers, where females lay eggs that are then guarded by the males. The rising water levels during the wet season ensure that the nests are submerged, protecting the eggs and providing a suitable environment for the young to hatch and grow. This reproductive strategy highlights the arapaima's adaptation to the dynamic and often harsh conditions of their habitat.