Swimming in ice

This daily blipping is harder than I anticipated. I'm sure I pass a hundred fabulous photo ops every day but they slide in and out of focus before I think to pull out my phone (how odd it is to write that) and take a picture. Anyway, this shot was taken at my local Fancy Chain grocery store. The fish caught my eye as I headed to the check out line, all red and shiny and dead. Does anyone know what kind they are?