Sharks

Sharks are a diverse group of cartilaginous fishes (class Chondrichthyes) known for their streamlined bodies, powerful tails, and multiple rows of replaceable teeth. There are over 500 extant species, varying widely in size, habitat, and behavior. Key Characteristics Skeleton: Made entirely of cartilage rather than bone, which makes them lighter and more flexible. Gills: 5–7 gill slits on the sides of the head (no operculum covering them like bony fish). Skin: Covered in dermal denticles (tiny t...