While sole and scrod are both mild white fish popular on restaurant menus–especially in New England–that is where the similarity ends. For one thing, sole is a variety of fish, while scrod is not.
The term “scrod” seen on restaurant menus is meant to describe a piece of white fish, most often, but not always, cut from cod. Cod is a large bottom-feeding fish popular with New England sports fishers. Most people think the name “scrod” comes from the old Dutch word “schrood” meaning shred or slice.
Other fish that you may be eating when you order scrod are haddock, cusk and pollock. These fish are much smaller than cod which can weigh 80 pounds or more. Sometimes fishermen sell all of their small white fish catch as “scrod” without separating it into distinct varieties of fish.
Sole is a variety of flatfish that lives on the sea floor, sometimes even nestling below the sand in order to disguise itself from its prey. Like other varieties of flatfish, such as flounder and halibut, sole have both eyes on the left side of their head.
There are a number of varieties of sole that make their way to the dinner table. These include line sole, Dover sole and yellowfin sole. Among these, Dover sole is the most prized.
Most sole are relatively small. Althought sole can live to be more than 40 years old they are rarely longer than 20 inches.
References and ResourcesScrod Definition and Word Origin
What is the fish listed as "scrod" in New England restaurants?
Yellowfin Sole Research