👉 The arm fluke, or pectoral fin fluke, is a small, flattened, and often colorful structure located beneath the main pectoral fins of fish, playing a crucial role in their locomotion. These flukes are part of the hind limb system and function similarly to the tail fin in larger fish, providing powerful propulsion through undulating movements. The arm fluke consists of a flexible, muscular body that aids in generating thrust, allowing fish to swim efficiently through water. Its unique shape and muscle arrangement enable precise control over direction and speed, making it an essential adaptation for both predation and evasion in aquatic environments.
