This isn't a can of sardines, it's a can of worms. Wasn't there something besides sardines to think about when you worked at the bait shop? Anyway, there definitely is a kind of live, swimming-around fish called a sardine. Better yet, there are many kinds of live, swimming-around fish called sardines. But there are things that we don't call sardines but are found in cans labeled "sardines."

Science guys classify what ordinary folk call sardines into a family called Clupeidae, with brothers and sisters: herrings, sprat, menhaden, and shad. The next step down the classification chart is a fish's genus, separating the Clupeidae into smaller groups based on physical characteristics and habitat. About 17 genera of fish called sardines. Next step, with very specific characteristics, is the fish's species. Dozens and dozens of "sardine" species from warm, cold, fresh, brackish, or marine waters around the world: Atlantic sardine, India-oil sardine, perforated-scale sardine,

Sardines with their heads chopped off are a slightly different matter. The FDA permits a can labeled "sardines" to actually be a can of fish of the genera that include sprats, brislings, and small herrings, all of them being so closely related. So there's your argument for a sardine not being a sardine until it's put in a can. There are actually two internet sources that make your argument, too, one a supposed high-toned chef and the other some guy who writes for the Boston Globe as "Dr. Knowledge."

Both claim sardines aren't sardines until they're in a can. Sure, occasionally a herring is a herring until it's put in a can labeled "sardines," but that's the exception. Worldwide, Sardina pilchardus is considered the "true" sardine; that's a fish the Brits call a pilchard, we call a sardine. Following United Nations guidelines, any fish sold as a sardine that is not a pilchard-type has to bear a clarification of exactly what species of sardine it is. Of course, this is much ado about a foodstuff nobody likes anyway.