What kind of fish does not have a bladder?

Many species of fish do not have a swim bladder, which is an organ that helps with buoyancy. Notable examples include cartilaginous fish like sharks and rays, as they rely on their large livers filled with oil for buoyancy instead. Additionally, certain bony fish, like some species of catfish, also lack a swim bladder. These adaptations allow them to thrive in their specific environments.