• 20 parts
  • Checked October 2026

Body Parts of a Clam

A hard-shell clam lying open in one half of its shell, then the marks inside the empty shell.

Body Parts of a Clam

Name Date

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
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Write the name of each numbered part.Answer key

  1. Foot
  2. Incurrent siphon
  3. Excurrent siphon
  4. Gills
  5. Mantle
  6. Anterior adductor muscle
  7. Posterior adductor muscle
  8. Mouth
  9. Stomach
  10. Digestive gland
  11. Intestine
  12. Heart
  13. Kidney
  14. Umbo
  15. Hinge teeth
  16. Hinge ligament
  17. Anterior adductor muscle scar
  18. Posterior adductor muscle scar
  19. Pallial line
  20. Pallial sinus

Drawn for this site on 2026-10-01 from plain geometry. Licence: own work.

Each numbered ring is a button. Use the arrow keys to move between them and Enter to choose. Names are read out in Study, and once a part is answered.

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All 20 parts on the diagram

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The body in its shell 13

  1. Foot The muscular wedge the clam moves with. It can reach out past the edge of the shell.
  2. Incurrent siphon The lower tube at the back. Water flows in through it, bringing food and oxygen.
  3. Excurrent siphon The upper tube at the back. Water leaves through it, carrying waste away.
  4. Gills Leaf-like sheets that hang on each side of the body. They take oxygen from the water that flows over them.
  5. Mantle A soft sheet that lines each valve. It makes the shell.
  6. Anterior adductor muscle The muscle at the front that pulls the valves shut. It runs straight across from one valve to the other.
  7. Posterior adductor muscle The muscle at the back that pulls the valves shut. Together the two muscles hold the shell closed.
  8. Mouth A small opening just behind the front muscle. Two pairs of small flaps beside it, the palps, sweep food in.
  9. Stomach A wide part of the gut inside the digestive gland. The mouth opens into it by a short gullet.
  10. Digestive gland A gland that surrounds the stomach, under the umbo. It makes digestive juice and is also called the liver.
  11. Intestine A narrow tube that loops low in the body. It then runs back through the heart and over the rear muscle.
  12. Heart Three chambers in a sac near the hinge. The end of the intestine runs straight through it.
  13. Kidney It lies under the heart, in front of the rear muscle. It takes waste out of the blood.

Inside the empty shell 7

  1. Umbo The raised beak near the hinge, the oldest part of the valve. The shell has grown outward from it.
  2. Hinge teeth Ridges just under the umbo. They lock with the teeth of the other valve and keep the two valves lined up.
  3. Hinge ligament A springy band that joins the two valves at the top. It pushes them apart when the muscles relax.
  4. Anterior adductor muscle scar The mark where the front adductor muscle was fixed to the valve.
  5. Posterior adductor muscle scar The mark where the rear adductor muscle was fixed to the valve.
  6. Pallial line A line near the lower edge that joins the two scars. It shows where the muscles of the mantle edge were fixed.
  7. Pallial sinus A notch in the pallial line, near the rear scar. It marks where the siphons pull back into the shell.

How this list was compiled: Every name checked on 2026-10-01 in two sources. H. S. Pratt, A Course in Invertebrate Zoology (1902, public domain), the hard-shell clam: the shell and its marks, the mantle, siphons, gills, foot and muscles, and the organs seen through the body wall, https://archive.org/details/courseininverteb00prat. Wikipedia, Bivalvia, Bivalve shell, Hard clam, Hinge teeth, Pallial line and Pallial sinus, https://en.wikipedia.org/wiki/Bivalvia. R. W. Hegner, College Zoology (1912, public domain), the anatomy of a bivalve: mouth, stomach, digestive gland, intestine, heart and kidney, https://archive.org/details/collegezoology00hegn. Licence: own work

The drawing: Drawn for this site on 2026-10-01 from plain geometry; nothing traced. Licence: own work

How it works

The body parts of a clam, drawn on a hard-shell clam. The first view shows the animal lying in one half of its shell. The second shows the marks inside the empty shell. Press Quiz me to label the clam anatomy yourself.

Read the full guide

The body

The front is at the left and the hinge is at the top. The mantle lines the shell. The foot points forward and down, the gills hang beside the body, and two siphons reach out at the back. An adductor muscle at each end closes the shell. Inside the soft body are the stomach in its digestive gland, the looped intestine, the heart and the kidney.

The shell

Switch to Shell. The umbo is the oldest part. Hinge teeth sit just under it, and the hinge ligament runs behind it. Each adductor muscle leaves a scar. The pallial line joins the two scars, and the notch in it is the pallial sinus.

  • The intestine runs straight through the heart on its way to the back of the clam.

Questions and answers

What are the body parts of a clam?

Two valves joined by a hinge, a mantle that lines them, a foot, gills, two siphons and two adductor muscles. Inside the soft body are the stomach, digestive gland, intestine, heart and kidneys.

What is the pallial line on a clam shell?

A line on the inside of each valve that shows where the muscles of the mantle edge were fixed. It runs near the lower edge and usually joins the two adductor muscle scars.

What do the siphons of a clam do?

They carry water. It flows in through the lower, incurrent siphon, bringing food and oxygen, and leaves through the upper, excurrent siphon, carrying waste away.

Does a clam have a heart?

Yes. It has three chambers, one ventricle and two auricles, and lies in a sac near the hinge. The end of the intestine passes through it.

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