tenth and a third of their muscle to that task,
usually a thin dark layer just under the skin.
But water’s resistance to movement increases
exponentially with the fish’s speed. This
means that fish must develop very high power
very quickly when accelerating. And so they
devote most of their muscle mass to an
emergency powerpack of fast-twitch white
cells that are used only for occasional bursts
of rapid movement.
In addition to red and white muscle fibers,
fish in the tuna family and some others have
intermediate “pink” fibers, which are white
fibers modified for more continuous work
with oxygen-storing pigments.
The Flavor of Fish
and Shellfish
The flavors of ocean and freshwater creatures
are very different. Because ocean fish breathe
and swallow salty water, they had to develop a