Carefully arranged on a bed of ice, the fish on the counter at Capitol Seafood in Jessup looked like a still-life composition.
Gold-stripped wild rockfish, their lips sporting blue plastic tags, lay in the upper left corner. Just below them were the smaller, dish-faced hybrid rocks raised on farms. To the right, the bright color of several red snappers contrasted with the plain brown of the flounder below.
Framed by these lesser species, two large, silver-sided creatures formed the composition's centerpiece. This striking pair were obviously Atlantic salmon, clear-eyed fish that even in death seemed poised to flop off the ice and rush up some fast-flowing river to spawn.
Yet closer inspection showed that these two fish were not quite the identical twins they seem at first glance. A barely visible iridescent pink beginning at the gills and running the length of its body revealed one of the two fish to be something other than an Atlantic salmon.
A steelhead, the clerk explained, selling for $4.50 a pound, or 25 cents less than the salmon.
So similar in appearance were the two fish that a shopper without a degree in ichthyology would be hard-pressed to tell the difference.
The resemblance between steelhead and salmon is of no small concern because of the large market for fresh salmon.
Americans consume about 185 million pounds of salmon a year. More than half of that is imported fish, much of it fresh Atlantic salmon produced on foreign fish farms.
Recently, salmon fish farms have begun to sprout along the coast of Maine and Puget Sound in Washington state. Today, those U.S. fish farms are producing about 10 million pounds of fish a year.
Given the huge demand for fresh salmon, a few intrepid souls suspect steelhead may have a bright future, but so far the fish has captured only a minuscule part of the market. One of the big hurdles for steelhead producers is the fish's name. A grilled steelhead steak may have the bright pink color of salmon and taste very similar, but consumers put off by the name won't try it.
Mary Nagel, vice president of Maine Coast Trading Co., which markets salmon and steelhead for fish farmers in Maine, said Giant Food Inc. has warmly embraced the name steelhead. "They said, 'Great, that's wonderful.' They're selling it to beat the band," she said.
But not everyone is so enthusiastic about trying to sell something that sounds like an auto part. "Most of the other retailers say they don't even know if it's fish or what," Ms. Nagel said.
Since steelhead are so similar to salmon, there's a strong temptation to try to get the word salmon into the name. For example, just a few doors down from Capitol Seafood at the Jessup fish market, Frank's Seafood was selling the silvery fish with the faint pink stripe in an ice-filled bin marked simply "salmon."
Karen Bossert, one of the owners of Frank's, said that when she identified the fish to her customers as steelhead many of them acted confused, until she explained that they are a kind of salmon. So now they simply label the fish as salmon.
Joanne Choate, a co-owner of Frank's, explained: "What most of our customers are interested in is how this tastes." And, she continued, "The look, the taste and the texture is identical to salmon."
Ms. Bossert and Ms. Choate say they are not playing fast and loose with the facts.
In their store they have a small red bound book called "Fresh Seafood, The Commercial Buyer's Guide." It says steelhead, a kind of rainbow trout that spends its adult life at sea and returns to fresh water to spawn, is commonly called steelhead trout and in Canada is known as steelhead salmon.
Steelhead "looks, behaves and tastes very much like Atlantic salmon," the book says. The author advises his readers: "In market terms, it is effectively salmon."
There is a long history in the industry of changing unpleasant common names of seafood species to more enticing ones. By this process, spider crabs became snow crabs.
The controversy over what to call a steelhead takes the confusion one step further, however, to include even discussion among scientists about what to call the fish.
Consider this: Despite the steelhead's former scientific name -- Salmo gairdneri -- which contains the Latin work for salmon, the fish cannot properly be sold under the name salmon.
Just to muddy things a bit further, the people who decide such things have reclassified the steelhead. It's official name is Oncorhynchus mykiss, but it still can't be sold legally as salmon, even though all other Oncorhynchus species can.
That's because the common name in general use is what matters when selling fish, not the scientific one, according to the U.S. Food and Drug Administration. In the case of the sea-run rainbow, the only acceptable name is steelhead. Not salmon trout, not steelhead trout. Just steelhead, period.
"It is closely related to salmon, but it's not a salmon," said Mary Snyder, the keeper of names in the FDA's office of seafood. "You've either got yourself a salmon or you've got yourself a trout. You can't use salmon as an adjective. The correct term is just plain steelhead."
Ms. Snyder said the penalty for misrepresenting fish can be severe, including seizure of the product. But typically the FDA takes much milder action. "We would probably just write them a letter telling them to knock it off," she said.
Salmon vs. steelhead
Distinguishing characteristic: Steelhead has a barely visible iridescent pink stripe beginning at the gills and running the length of its body.
U.S. salmon consumption, 1990: 0.726 pounds per person
Price: Salmon: $4.75 per pound
Steelhead: $4.50 per pound