Campbell's Tomato Bisque - Is it?

I had reason to think back to my childhood when I was allowed to select a can of Campbell's soup for my afternoon lunch, and I although it wasn't my favorite (best enjoyed with crackers though), Tomato Bisque was one of the options.

Jump ahead decades later and it dawns on me just now that to technically be defined as a "bisque", shouldn't there need to be some sort of shellfish in it? (which of course Campbell's doesn't have)

So, let me pose this question to my peeps in the heart of seafood heaven...need there be shellfish in order for it to be called a bisque or can the term simply refer to the cream base?



On a funny side note, as a young adult I had to relearn how to pronounce the word "bisque". I knew how to say "risque" (ri'ska) correctly when I was younger but never heard "bisque" (bisk) said out loud, so I assumed that by simply replacing the first letter it would be spoken the same way. I called it ri'ska for years.