While cleaning a saltwater aquarium, students placed a family of fiddler crabs from the saltwater aquarium into a container of distilled water. What effect will this have on the crabs?

Question

abb0t · Answer

They may not be able to live, because, unlike salmon, who can live in both salt water and non-salt water, they will die. Salt usually causes dehydration in an organism. I'm guessing this would be same case for the fiddler crabs. They would not obtain the proper salt nutrients to allow them to live optimally. 

Refer to your  book. I am just making a broad speculation from what I know.

anonymous · Answer

They would most likely get dehydrated.  This is due to osmosis and diffusion on the crap the salt water is the high concentration and the distilled water is the low.