Pectoral fin
A paired appendage attached to a fish’s body behind the head. Its shape and movements help produce thrust, steer, brake, hover, or stabilize the fish.
Fin locomotion: Swimming driven by the movement of fins rather than body undulation. Pectoral fins are among the appendages that propel and maneuver fish.
Fish fin: A body appendage that helps a fish move, steer, stabilize, or control depth. Pectoral fins are one of the major paired fin types in fish.
Fish locomotion: The ways fish move through water using body undulation, fins, or both. Pectoral-fin use is one strategy within the broader range of fish swimming modes.
Flying fish: A marine fish that launches from the water and glides on enlarged fins. Its enlarged pectoral fins act as gliding surfaces after takeoff.
Hydrodynamics: The study of forces and motion in liquids, including water flowing around moving bodies. Water pressure and flow explain how a pectoral fin produces thrust and lift.
Pectoral girdle: The skeletal structures that attach and support the pectoral appendages of vertebrates. The girdle anchors the fin and transmits forces between it and the body.
Maneuverability: The ability to change direction, speed, or orientation with control. Pectoral fins let fish make rapid turns and precise adjustments at low speeds.
Batfish: A fish that uses enlarged, limb-like pectoral fins to move along the seafloor. Its pectoral fins are adapted for walking-like movement rather than ordinary swimming.
Lift-based propulsion: Propulsion produced when a moving surface generates lift through its interaction with a fluid. Some fish sweep pectoral fins to generate thrust from lift, rather than simply pushing water backward.
Fin membrane: The thin tissue stretched between the supporting elements of a fin. Its deformation changes the pectoral fin’s effective shape in water.