Hey, Charlie, look at this tuna!

"Almost everybody has canned tuna in the cupboard," says Barbara-jo McIntosh, author of "Tin Fish Gourmet," which contains recipes for canned seafood products. The Vancouver, B.C., resident says this is true even where fresh seafood is plentiful. "It's one of those things that when people are shopping, they just naturally put in their basket."

Why? Because it's convenient, versatile, nutritious, and inexpensive.

"Basically, no matter what your budget is, people can afford canned tuna," says Michael Mullen, a spokesman for StarKist Seafood, the leading American seller of canned tuna, with about 45 percent of the market.

Grocery stores, he says, often discount tuna, selling it below cost as a "loss leader," since tuna generates other sales.

"If you buy canned tuna," Mr. Mullen says, "the likelihood is you are also going to buy mayonnaise, you're going to buy bread, maybe celery to mix into it, and butter." Tuna cans stacked sky high at the end of grocery aisles have long been a common sight in supermarkets. But those days may be numbered.

Tuna packaging is changing. Last October, StarKist introduced tuna in a vacuum-sealed foil pouch. The Bumble Bee brand followed suit, and Chicken of the Sea, the other member of America's Big Three tuna processors, now includes a pouch with its tuna-salad kits.

The industry expects this packaging breakthrough to rejuvenate sales, which have been flat for the past five years, with about 2.1 billion cans of tuna consumed in the US each year.

The pouch "will change the way people think of, and use, tuna," says Peter Bowen, Star-Kist's CEO.

In a consumer survey, the company found that people who tested the pouch in home trials preferred the new product 5 to 1 over canned tuna.

The company claims pouched tuna is fresher-tasting and firmer because of less cooking and processing. Its shelf life, though less than the four or more years for tuna in cans, is a respectable 18 months.

Greater convenience for consumers is another selling point. Can openers aren't needed, and the tuna is ready the second the pouch is unsealed. Draining isn't necessary.

Unlike canned tuna, which comes packed in water or oil, tuna in a pouch contains only enough liquid to keep it moist. A 6-ounce can of tuna contains about an ounce of water or oil, whereas a 7-ounce pouch of tuna is almost pure fish.

Not only does this new packaging upgrade "canned" tuna's image, it makes it more portable than ever - making it better suited for camping or field trips, or even lunch at the office.

The most popular way to eat tuna, however, is not straight out of the package, but mixed with other foods.

The top use of tuna in households, Mullen reports, is for sandwiches, which account for 58 percent of US consumption. Salads are next at 20 percent, with casseroles and other combo/helper uses coming in third at 13 percent.

Maybe because so many people eat tuna from a can, Ms. Mcintosh says: "It's not like fish to a lot of people. That sounds funny, but that's what they tend to say. When they have tuna in a casserole, for example, they don't feel like they are eating a fish product."

Whether people begin to see tuna in a new light now that it's in jazzier packaging, remains to be seen. For now, at least, cans and pouches sit side by side on the grocery shelves.

This might lead some environmentally conscious consumers to weigh the merits - or demerits - of the two packing choices.

The steel cans are recyclable The pouches - a mix of foil, plastics, and adhesives - are not.

StarKist's Mullen, however, says the pouches are more environmentally friendly, because it takes less than half as much energy to make them as to make the cans.

No matter what options Americans choose, it's clear they will go on eating tons of tuna. Statistics show that 89 percent of American households currently eat canned tuna.