their body is the tender mantle and food-
trapping gills.
Scallops neither attach nor bury
themselves. They lie free on the ocean
floor, and escape predators by
swimming. Their massive central muscle
claps their shells shut and forces water
out one end, thus propelling them in the
other direction.
Squids and octopuses are molluscs turned
inside out and transformed into highly
mobile, streamlined carnivores with
large eyes and arms. The remnants of a
shell provide an internal support, and the
mantle is now a specialized muscular
sheet that expands and contracts to
provide jet propulsion through a small
funnel derived from the foot muscle.The immobile molluscs do very well in
aquaculture. They can be raised in large
numbers in the water’s three dimensions,