You’ll notice a significant time difference when cooking fish and chicken, especially when boiling them. Fish cooks faster because its muscles are softer and less dense than chicken. This is because they live in the water. When we are floating in the water, we feel lighter, and when we come out, our bodies feel much heavier. The same goes for fish; they always feel light due to the buoyancy of the water. So there was no need for them to evolve stronger muscles to support their weight. The heavier you are, the stronger you have to be. So land animals have thicker and stronger muscles, which take longer to cook.
Size Difference in Sea and Land
Also, land animals can’t get as big as sea animals because they have to support much heavier weights. This is why the biggest land animal, the African Elephant weighs only around 5000 KG, but the biggest sea animal, the Blue Whale weighs around 150000 KG.
The main problems with being too big are being too heavy and not getting enough oxygen supply to all body parts. If these problems can be solved, then land animals can also get bigger.
If the Earth were smaller than its current size, its gravity would be lower and hence you would weigh less even if you are big. In this case, animals on Earth would be bigger in size. Conversely, if the Earth were bigger than its current size, animal sizes would be smaller.
Animal sizes would also get bigger if the Earth’s atmosphere had more oxygen content since that would make oxygen supply to body parts easier. Currently, the earth’s atmosphere contains around 21% oxygen, but 66 to 100 million years ago the oxygen content was around 30 to 35%. This is why dinosaurs could grow up to 50000 KG even though they were land animals.
A Dinosaur bone discovered in France:
Difference in Intelligence
Fish not only cooks faster than chicken, it’s also stupider than chicken. The environment on the land is much more complex than the sea environment. You need more intelligence to navigate a complex environment. On land, you can use your intelligence to make tools from stones, make fire, do agriculture, build houses, etc. But at sea, it’s just water everywhere. There isn’t much value for high intelligence. Some sea animals, like dolphins, show higher intelligence than others, but there are a lot more intelligent animals on land with much higher intelligence.
Reference Links
https://www.google.com/search?q=why+land+animals+are+not+as+big+as+whales