Teleosts, also known as teleostei, are a diverse group of ray-finned fish that belong to the superclass Actinopterygii. They represent one of the most advanced and abundant groups of vertebrates, encompassing over 30,000 described species.
The term "teleost" derives from the Greek words "teleios," meaning complete, and "osteos," meaning bone, referring to their fully ossified skeletons. They are characterized by the possession of a swim bladder, an air-filled sac that aids in buoyancy control. Most teleosts also possess symmetrical tails, scales covering their bodies, and a terminal mouth position.
Teleosts are found in various aquatic habitats worldwide, including freshwater, saltwater, and brackish environments. They exhibit an enormous diversity in size, ranging from tiny species measuring a few centimeters to the gigantic ocean-dwelling teleosts like sunfish and marlins.
These fish display remarkable ecological adaptability and have successfully colonized almost every aquatic niche available. They demonstrate a wide array of feeding strategies, including herbivory, omnivory, carnivory, and even parasitism. Teleosts also exhibit a variety of reproductive strategies, such as external and internal fertilization, as well as viviparity and ovoviviparity.
The economic importance of teleosts is immense, as they account for the majority of commercially exploited fish species worldwide. They are widely consumed for their nutritional value and are of significant cultural, recreational, and scientific interest. As a result, the study of teleosts plays a crucial role in aquatic biology, ecology, and fisheries management.
