Every other fish I can think of has bones but sharks do not. Why is this?
In: Biology
Short answer is because they came first. The was a hot moment in time when fish were evolving and one of the first adaptations was cartilage as a structural system – it’s really light, it’s super flexible, and it’s not nutritionally intense to maintain. It wasn’t great at everything though – having squishy teeth and jaws don’t work all that well so a lot of those early fish had beak like mouths and no jaws at all, just a sort of fixed opening. Imagine a sort of underwater Death-Parrot that can’t open or close it’s beak.
Eventually a new thing, called “bones”, started evolving which was strong but heavy and takes a lot of energy to maintain. A lot of fish developed boney heads and teeth and a new-fangled hinge separating their skull from this new thing we now call a ‘jaw’.
That’s where sharks basically spun off, they are speed swimmers who are so good at eating whatever they need to eat with their new jaws and teeth nothing really required them to change. If we’re talking time line, sharks are to dinosaurs as the dinosaurs are to us. *that’s how long sharks have ruled the oceans.*
Other fish started really liking these bone things and started working the bones into their bodies.
Sharks are part of a broader family of fish that never jumped on the bones bandwagon fully and they are called the ‘cartilaginous fish’ which also includes skates, rays, and a variety of shark-like fish you’d probably just thing are baby sharks if you saw them swimming around.
Latest Answers