The fat content of fish muscle runs a
tremendous range, from 0.5% in cod and other
white fish to 20% in well-fed herring and their
relatives (p. 184). Fat storage cells are found
primarily in a distinct layer under the skin,
and then in the visible sheets of connective
tissue that separate the myotomes. Within a
given fish, the belly region is usually the
fattiest, while muscle segments get
progressively leaner toward the back and tail.
A center-cut salmon steak may have twice the
fat content of a slice from the tail.
Fish anatomy. Unlike the muscles of land
animals (p. 120), fish muscles are arranged in
layers of short fibers, and organized and
separated by sheets of connective tissue that