during its prolonged dives, have 25 times
more myoglobin in their cells, and are nearly
black.
Fiber Proportions: White Meat and Dark
Meat Because most animal muscles are used
for both rapid and slow movements, they
contain both white and red muscle fibers, as
well as hybrid fibers that combine some
characteristics of the other two. The
proportions of the different fibers in a given
muscle depend on the inherited genetic design
for that muscle and the actual patterns of
muscle use. Frogs and rabbits, which make
quick, sporadic movements and use very few
of their skeletal muscles continuously, have
very pale flesh consisting mainly of white fast
fibers, while the cheek muscles of ruminating,
perpetually cud-chewing steers are
exclusively red slow fibers. Chickens and
turkeys fly only when startled, run
occasionally, and mostly stand and walk; so