Teleosts are a diverse group of fish that belong to the class Actinopterygii. They are characterized by their bony skeletons, which differentiate them from other fish types like chondrichthyans, which have cartilaginous structures. Teleosts make up the largest group of vertebrates, with over 30,000 species, including familiar fish like salmon, tuna, and goldfish. These fish are found in various aquatic environments, from freshwater rivers to the deep sea. Teleosts exhibit a wide range of adaptations, such as specialized fins and swim bladders, which help them thrive in different habitats. Their evolutionary success is attributed to their ability to exploit various ecological niches.