Atlantic salmon

Would you be able to tell if the wild Alaskan sockeye salmon you ordered for dinner was swapped out for a less expensive piece of farm-raised salmon?

For the observant, the color difference between the two would likely be the first giveaway. (Sockeye has a deeper red-orange hue.) Or maybe you'd notice the disparity in the thickness of fillet. (Sockeye is flatter and less steaky in appearance.)

Don Taylor / Flickr

A new study of genetically-modified Atlantic salmon shows they can breed with their wild counterparts. Critics worry escaped farmed fish could weaken wild stocks.