“adductor” (from the Latin adducere, “to
bring together”), which extends between the
broad ends of the shell and contracts to
overcome the spring force of the ligament.
Tender Quick, Tough Catch The adductor
muscle has to perform two very different
kinds of work. One is to close the shell
quickly to expel sediment, accumulated
wastes, or eggs, or to slam the door on
predators. The other is to keep the shell
tightly closed for hours, sometimes even days,
until the danger passes. These two jobs are
performed by adjoining parts of the muscle.
The fast-contracting “quick” portion is quite
similar to the fast muscles of fish and
crustaceans; it’s white, translucent, and
relatively tender. But the slow, tension-
maintaining “catch” portion is among the
strongest muscles known, and can maintain its
contraction with very little expenditure of
energy, thanks to biochemical tricks that lock