Teleostei
Teleostei is a diverse and successful group of ray-finned fishes that comprises the vast majority of modern fishes. With over 30,000 species, they dominate aquatic ecosystems worldwide, including both freshwater and marine environments. This group is characterized by a unique set of features that have contributed to their evolutionary success, including a specialized skeletal structure, advanced sensory systems, and efficient swimming mechanisms.
Common Names
Teleostei is a scientific name and does not have a common name in general use. However, individual species within this group are known by various common names depending on their geographical distribution and local languages.
Characteristics
Teleosts share a number of common features that distinguish them from other bony fishes. Some of the most prominent characteristics include:
- Homocercal caudal fin: Teleosts possess a symmetrical tail fin with the vertebral column extending into the upper lobe, unlike the heterocercal tail fins of sharks and some other primitive fishes.
- Cycloid or ctenoid scales: Most teleosts have scales that are either smooth (cycloid) or spiny (ctenoid). These scales help protect the fish and reduce drag during swimming.
- Bony operculum: The operculum, a bony flap covering the gills, is present in all teleosts. This structure protects the gills and allows for efficient respiration.
- Swim bladder: Teleosts typically have a swim bladder, a gas-filled sac that helps regulate buoyancy and allows the fish to maintain its position in the water column.
- Advanced sensory systems: Teleosts have well-developed sensory systems, including lateral lines, olfactory organs, and eyes, which aid in detecting prey, predators, and navigating their environment.
Environments
Teleosts have adapted to a wide range of aquatic environments, including:
- Marine: The vast majority of teleost species live in saltwater oceans and seas, ranging from coastal areas to deep-sea environments.
- Freshwater: Many teleosts have adapted to live in freshwater lakes, rivers, and streams.
- Brackish: Some species can tolerate environments with a mixture of fresh and saltwater, such as estuaries and mangrove swamps.