Elasmobranchii

Elasmobranchii is a scientific subclass that includes sharks, rays, and skates. These fish are characterized by having skeletons made of cartilage (lighter and more flexible than bone), five to seven gill slits on the sides of their heads, and bodies often adapted for swimming efficiently. They are mostly predators or scavengers, playing crucial roles in marine ecosystems. Elasmobranchii diverged from other fish hundreds of millions of years ago and have unique features like placoid scales, which give their skin a rough texture and aid in hydrodynamics. They are vital for maintaining healthy oceanic food chains.