Osteichthyes, commonly known as bony fish, form a remarkable group of vertebrates distinguished by their mineralized skeleton made primarily of calcium phosphate. This adaptation not only provides structural support but also enables greater mobility and versatility compared to cartilaginous fish. Alongside their bony skeleton, Osteichthyes possess a unique respiratory system featuring gills covered by an operculum, facilitating efficient gas exchange.
- Osteichthyes are vertebrates with a skeleton made of bone, not cartilage.
- They use gills for breathing, covered by a protective operculum.
- Include both ray-finned and lobe-finned fish, making up over 95% of all fish species.
- Highly diverse, inhabiting nearly all aquatic environments from freshwater to deep oceans.
The class Osteichthyes encompasses two major groups: Actinopterygii (ray-finned fish) and Sarcopterygii (lobe-finned fish). Ray-finned fish dominate the seas and freshwater systems with their delicate, supportive fin rays, while lobe-finned fish boast fleshy, muscular fins that are evolutionary precursors to tetrapod limbs. Together, these adaptations have allowed bony fish to radiate into an astonishing variety of forms, sizes, and ecological niches across the planet’s waters.