c. Foot. The foot is a muscular organ the clam uses to move about and to dig.
Once the shell is opened, the foot extends through the opening. The clam moves by
attaching the foot to an object and then pulling its body towards the object.
Figure 2-3. Internal Features of Clams
d. Siphons. There are two siphons, an incurrent and an excurrent. Water
containing food particles is drawn in through the incurrent siphon across the gills and
palps. Used water containing body wastes is removed by the excurrent siphon.
2-6. ANATOMICAL FEATURES OF SCALLOPS
A scallop is a moveable bivalve found in shallow coastal waters and in depths up
to 150 fathoms. Figure 2-4 shows the entire internal anatomy, but the adductor muscle
is the only part that is used as food. The scallop cannot close its shell as tightly as does
the oyster and clam (it will not stay closed). Therefore, it is subject to rapid
deterioration. For this reason, scallops are shucked at sea and all but the adductor
muscle is discarded. The adductor muscle is creamy white to a light orange color. The
food inspector needs to be aware that occasionally some vendor may try to substitute
shark plugs for scallops.
Figure 2-4. Internal Features of Scallops