Biology / Unit 10 Bio 2293 short lesson, about 20 seconds
Cartilaginous versus Bony Fishes
Captions available
The idea
Cartilaginous fishes, such as sharks, build their skeleton from cartilage; bony fishes, the more diverse group, build theirs from bone.
In practice
A ray's flexible cartilage skeleton contrasts with a tuna's rigid bony skeleton, including the buoyancy-control swim bladder many bony fishes use.
Where people slip
Cartilage is not an unfinished form of bone — cartilaginous fish retain it as a stable adult material.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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