The Order Rajiformes comprises cartilaginous fishes commonly known as rays and skates. They are closely related to sharks and are characterized by flattened bodies, enlarged pectoral fins fused to the head, and gill slits located on the underside. Most species are bottom-dwellers, living on sandy or muddy ocean floors, and feed on invertebrates and small fish. Some, like stingrays, possess venomous spines for defense, while skates are generally harmless. Rajiformes play important roles in marine ecosystems as predators and prey, and many species are sensitive to overfishing and habitat disturbance.