difference between SW and FW eels?

[ManEatingGuppy]

i was looking around at some fish stores today and saw a couple of FW eels that looked like SW i always see at my lfs, they are brown covered with tan spots, anyone know how to tell the differnce between these two?

 

[Fizhstiks]

The freshwater morays you saw actually need marine conditions as they grow older. They are born in freshwater, and they swim out to saltwater as they age. They usually dont last long in freshwater:

http://wetwebmedia.com/FWSubWebIndex/fwmorayeels.htm

 

[ManEatingGuppy]

so i can save some money and buy a FW eel and acclimate it to SW?