A Wonderleaf question
Do fish get thirsty?
a real page from the book
Some fish do get something like thirsty, and some do not. Ocean fish lose water into the salty sea, so they drink and push extra salt out through their gills. Freshwater fish have the opposite problem: water keeps entering them, so they rarely drink.
The key idea is osmosis, the way water moves toward saltier stuff when a thin barrier sits between them. That means a tuna and a goldfish can both be healthy fish while handling water in completely opposite ways.
Wonder words
- osmosis
- gills
- saltwater
- freshwater
Try it out
At dinner, compare a salty cracker and a cucumber, then talk about which one would pull more water toward it.
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