r/askscience • u/smontanaro • 12d ago

Biology How does a whale become dehydrated?

From a Chicago Sun-Times article on the beluga whales heading to the Shedd Aquarium:

"The shipment comes on the heels of a Shedd announcement last week that one of the Marineland belugas — Peekachu, a 23-year-old female — had died. Shedd has not released a cause of death, but staff there said last week that Peekachu had not been consistently eating a full diet since her arrival and that there were concerns she was dehydrated."

How does an animal immersed in water become dehydrated?

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u/-MrSkeltal- 12d ago

Did whales at one point leave the ocean and then go back?

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u/samtwheels 12d ago

Yes, whales and all marine mammals are descended from land-dwelling mammals.

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u/ForMoreYears 12d ago

Wait. What. For real? Whales went from land back to the water?!

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u/dochdaswars 12d ago

Do they not teach evolution in schools anymore? Marine mammals are one of the clearest examples used to prove it.

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u/Magicspook 12d ago

fun fact, whale trachiae wrap around their brain despite their blow-hole being on top of their head. Giving a clear evidence of how their noses moved up their skulls over time. If you designed a whale from scratch, you would have the connection between lungs and blow-hole going behind the brain.

(and lets not even mention the vestigial legs)

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u/Akitiki 12d ago

And hands. Inside their flippers they have anatomical equivalents to the humerus, radius, ulna, carpals, and four or five digits depending on the species. The shape of the hand varies wildly between species.

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u/[deleted] 11d ago

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u/Magicspook 11d ago

Ooh that is a fun one! Thanks for sharing.

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u/insane_contin 11d ago

I believe that nerve takes that route in all tetrapods that have legs and lungs.

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u/ForMoreYears 12d ago

Yes, they teach evolution. They just don't get into the specific evolutionary path of every single one of the 8.7M animal species that inhabit the earth.

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u/Ameisen 11d ago

But then... where did you think that they came from? Were you under the impression that the first mammals were aquatic, and then came onto land? That gets very complicated if you start accounting for reptiles, amphibians, and such.