>>8118012I want to wait till Anya's totsu, but here you are:
1. Sharks have cartilage skeletons & biologically impossible to go into the land.
2. Cartilage skeletons also fare badly in freshwater due to buoyancy. So most sharks do require the le salty gremlin to live.
3. Cartilage requires less calcium & sharks use their calcium for their infinity teeth & teethy skin instead.
4. Sharks' skin actually helps to support their body like a tough sack.
5. Sharks' body is hydrodynamic & they create lift when they swim, that is to counter the fact that they have no swim bladder.
6. They also breathe when they swim because they have no active gill flaps.
7. Sharks fare badly in cold water not only most of them can't generate heat on their own, but they also lack blubber to insulate them.
8. Sharks also fare badly if the water is too warm because warm water holds less oxygen & they need to swim faster just to breathe.
9. Most sharks have trouble swimming fast, like tuna fast, for a long time not because they lack the muscle, but because their rough skin creates more cavity bubbles & that can literally tear their internal body apart.
10. Sharks evolve really fast, the majority of sharks alive today are fairly recently evolved.
And that is just sharks in general, specific sharks' topic can fill multiple dictionares.
