Red Snapper, a species found in the Atlantic and Gulf of Mexico, is in
itself
an American substitute for the Ma-Dai or "Tai" of Japan, which is sometimes
translated as Japanese Red Sea Bream. The Red Snapper falls under the
category of Fue-Dai in Japan and is not a common sushi neta. Tai, is widely
farm raised in Japan and is a sushi staple. In truth the flavor of raw Red
Snapper and Raw Tai are very close and so are their prices, since the Tai
must
be imported from Japan. Hence, using Tai (Red Sea Bream) is not a substitute
for using Red Snapper, in fact it's the opposite. Of course, it should not
be labelled as "Red Snapper" since that name is tightly controlled in the
US.
The use of Tilapia, a freshwater farmed fish is something else since it's
not
really related to the Red Sea Bream or the Red Snapper, both sal****er fish.
Plus, Tilapia sells for about half the price of the other two fish. And in
my humble opinion falls short of the other two on flavor as well. While
freshwater fish are generally not consumed in raw form, Tilapia has come
into use because of the farmed environment. About 10-15 years ago, Taiwan
which produces alot of farmed Tilapia managed to break into the Japanese
sushi market under the name "Izumidai" (freshwater bream) especially at the
low-priced end kaitenzushi places. It has never been accepted into the
higher end taditional Japanese establishments. In the US where the vast
majority of "sushi restaurants" are Korean or Chinese owned, the use of
Tilapia is understabably more widespread. In Korea there is a practice of
eating freshwater fish raw to start with, which doesn't exist in Japan.