Yes indeed the snapping and popping sound is caused by snapping
From National Geographic:
"Among the fascinating creatures of the deep is a finger-size shrimp
with an oversize claw—resembling a boxing glove—that it uses to stun
its prey by snapping the claw shut. The snapping produces a sharp
cracking sound. When colonies of the shrimp snap their claws, the
cacophony is so intense that submarines can take advantage of it to
hide from sonar.
The shrimp, Alpheus heterochaelis, is a dirty-green crustacean that
prowls the shallow waters of tropical seas. It has two claws', one
resembling an oversize boxing glove, which it uses to stun prey, such
as small crabs, by snapping the oversize claw shut.
Reported in the September 22, 2000, issue of Science that the
stunning snap comes not from the clap of the claws coming together
but from a bubble generated by the claws' rapid closing motion.
When the claw snaps shut, a jet of water shoots out from a socket in
the claw at speeds of up to 62 miles (100 kilometers) an hour,
generating a low-pressure bubble in its wake. As the pressure
stabilizes, the bubble collapses with a loud bang."