Paying top dollar for 'daeha'? It might not be the real thing

As autumn reaches its midpoint, tanks at fish markets fill up with seasonal "daeha" — the large shrimp prized for their plump, meaty flesh. Restaurants selling them draw long lines of eager diners.

But many of those shrimp may not be the real thing.

True daeha belong to the family Penaeidae and are caught in the coastal waters of Korea's West and South seas, with autumn as their peak season. They die almost immediately after being pulled from the water, making them nearly impossible to farm. The shrimp swimming in fish market tanks are, for the most part, not daeha at all.

What most Koreans are actually eating is the whiteleg shrimp — named for the pale white coloring on its legs. Native to the Pacific coast of South America, it is now farmed around the world, including in Korea, and is available year-round.

Size alone is not a reliable guide. Whiteleg shrimp can be raised to a large size through farming, and daeha themselves vary considerably in size. Assuming that "big shrimp equals daeha" is simply not accurate.

There are a few more reliable ways to tell them apart. On a true daeha, the pointed antennae on the head extend well beyond the rostrum. On a whiteleg shrimp, the antennae tend to be shorter than the rostrum.

Daeha are generally grayish or brownish in color, with irregular dark markings on the body. Live specimens can appear darker depending on their condition or surroundings, and the tail area is often tinged red.

Whiteleg shrimp, by contrast, are relatively pale and semi-transparent, with a more uniform color overall. The white coloring on the legs — the feature that gives the species its name — is clearly visible.

Color alone, however, cannot provide a definitive identification. Appearance can shift depending on whether the shrimp is alive, freshly dead, refrigerated or frozen. Lighting conditions and the tank environment can also affect how the color looks.

Selling domestically farmed whiteleg shrimp under the name "daeha" carries little legal risk, because the word is also used as a general term meaning simply "large shrimp." Many market stalls and shops already label their product "farmed daeha" while selling whiteleg shrimp.

Consumers tend to assume they are buying a farmed version of the real species, when in most cases they are not. Some advocates argue that regulations should be tightened to require sellers to label the product accurately as whiteleg shrimp rather than farmed daeha.

Selling imported Chinese whiteleg shrimp as domestic daeha, however, is a clear violation of the country's country-of-origin labeling law.

In terms of taste, whiteleg shrimp hold their own against true daeha — the difference is difficult to detect on the palate. They are also cheaper, available in all seasons and can be sold fresh, meaning they can even be eaten as sashimi. For many consumers, they may actually be the better choice.