#acanthopterygian

• Acanthopterous — An organism or anatomical feature specific to fishes of the superorder Acanthopterygii, characterized by the presence of hard, sharp, and unbranched rays in the anterior part of the dorsal and anal fins. As an adjective, it describes a fin structure equipped with rigid bony spines used for self-defense and efficient hydrodynamic stabilization during swimming.
• Acanthopterygian — A term designating teleost fishes of the superorder Acanthopterygii, characterized by rigid, unjointed spiny rays in the anterior portions of the dorsal and anal fins, as well as a closed swim bladder (physoclistous). They constitute the most ecologically diverse and evolutionarily advanced group of modern fishes, occupying a vast array of marine and freshwater niches.