Thunniformia

Thunniformia is a superorder of ray-finned fishes that includes the mackerel and tuna families. These fish are characterized by their highly streamlined, torpedo-shaped bodies, which are adapted for fast swimming. They possess deeply forked tails and finlets behind the dorsal and anal fins, which further enhance their hydrodynamic efficiency. Thunniform locomotion is highly specialized, involving the powerful oscillation of the caudal peduncle and tail fin, while the rest of the body remains relatively rigid. This allows for rapid acceleration and sustained high speeds.

The members of Thunniformia are predominantly marine and occupy a wide range of oceanic environments, from coastal waters to the open ocean. Many species are migratory, undertaking extensive journeys for feeding and reproduction. They are generally carnivores, preying on smaller fish, squid, and crustaceans. The group includes some of the fastest-swimming fish in the world, such as various species of tuna. Their muscular bodies are rich in myoglobin, giving their flesh a characteristic red color and enabling them to maintain elevated swimming temperatures. The ecological and economic importance of Thunniformia is significant, with many species being highly sought after for commercial fishing and as game fish.