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> Plenty of land mammals have gone back to aquatic living but they don’t regain gills so they still go back to the surface. Breathing air is probably a superio
by MichaelCollins 4y ago
> Plenty of land mammals have gone back to aquatic living but they don’t regain gills so they still go back to the surface.
Breathing air is probably a superior system anyway, since mammalian fish utterly dominate gilled fish in nearly every respect. What gilled fish can dive like a sperm whale, acquire the bulk of a blue whale, or the agility of a dolphin?
- Retric 4y agoWhat’s the point of diving like a sperm whale if you can just stay at the bottom of the ocean? As to overall performance the fastest swimmer is the Indo-Pacific Sailfish clocked at 68 mph. The blue whale is more bulky and faster than a whale shark, but young whale sharks can simply dive too low to be at significant threat from Okra. So breathing has real disadvantages.
- MichaelCollins 4y agoWhat's the point of having gills to stay at the bottom of the ocean if you're going to get dominated by sperm whales anyway? I don't know if sperm whales eat young whale sharks, but they certainly could if they wanted to. They can dive deeper than any whale shark.
- Retric 4y agoWe don’t have any evidence that sperm whales attack them. Okra packs have been observed attacking juvenile baleen whales on the other hand.
- oneoff786 4y agoAre you the superior system if you’re at the top of the food chain but your species’ continued existence is more tenuous than the lower prey animals?
- MichaelCollins 4y agoI think the greatest threat to marine mammals is the decline of all the other fish they eat.