A worker at my LFS who for the most part offers great advice when it comes to fish keeping, also has respectable knowledge when it comes to fw rays. He has told me that feeding fw rays saltwater foods such as mussels or clams etc. It not advised due to them not being able to digest salty foods well. I didn't believe it when he first told me as I've done tons of research before purchasing my first retic and never read or heard anything like that so my question is does anyone know this to be true or have heard this before?