How do electrical eels carry charge through water and survive?

Question: How do electrical eels carry charge through water and survive?
- Keywords:
  eel,
  electricity,
  water
Asked by jayskar to Ed, Hayley, Jason, Nathan, Sophie on 18 Mar 2013.
- Hayley Evers-King answered on 18 Mar 2013:
  
  They don’t always produce the charge, they only do it in defence or when they want to shock prey. I still wouldn’t want to be in the water near one though!!!

Question: How do electrical eels carry charge through water and survive?