From Latin 'cartilago' (gristle), of uncertain deeper etymology — possibly connected to 'cratis' (wickerwork).
A firm, flexible connective tissue found in various parts of the body, including the joints, ear, nose, and between the vertebrae of the spine.
From Latin 'cartilāgō' (cartilage, gristle), genitive 'cartilāginis,' of uncertain ultimate origin but likely connected to Latin 'crātis' (wickerwork, hurdle, lattice), from PIE *kert- (to twist, to weave, to entwine). The semantic link lies in the fibrous, interwoven structure of cartilage tissue, which resembles wickerwork at a microscopic level. Some scholars alternatively connect it to PIE *kar- (hard
Sharks have no bones — their entire skeleton is made of cartilage. This is not a primitive condition they failed to evolve past: sharks had ancestors with bone, and they secondarily lost it. A cartilage skeleton is lighter than bone, which helps with buoyancy, and more flexible, which aids rapid maneuvering