Rayfins

Rayfins, a term often used colloquially, refers to the fins of fish that are supported by bony spines or rays. These rays are distinct from the fleshy, lobe-like fins found in some other fish groups. In ray-finned fishes, the fins are typically thin membranes stretched between these bony or cartilaginous rays. This skeletal structure provides support and allows for a wide range of movements, from precise maneuvering to powerful propulsion. Ray-finned fishes, also known as Actinopterygii, represent the vast majority of fish species living today, encompassing a remarkable diversity of forms and habitats. Their fins are crucial for locomotion, balance, and in some cases, defense or display. The arrangement and structure of these rays can vary significantly among different species, reflecting adaptations to their specific ecological niches. For instance, the pectoral and pelvic fins, homologous to the limbs of terrestrial vertebrates, are often used for steering, braking, and even walking on the seabed in some species. The dorsal and anal fins provide stability, while the caudal fin, or tail fin, is primarily responsible for forward thrust. The evolution of ray fins has been a key factor in the ecological success of this large group of aquatic vertebrates.