Acorn barnacle

Acorn barnacle and acorn shell are vernacular names for certain types of stalkless barnacles, generally excluding stalked or gooseneck barnacles. As adults they are typically cone-shaped, symmetrical, and attached to rocks or other fixed objects in the ocean. Members of the barnacle order Balanomorpha are often called acorn barnacles.

In addition, several species of barnacles are specifically called by the common name "acorn barnacle", including:

• Balanus glandula, common acorn barnacle
• Balanus nubilus, giant acorn barnacle
• Chthamalus antennatus, acorn barnacle
• Megabalanus coccopoma, titan acorn barnacle
• Megabalanus tintinnabulum, titan acorn barnacle
• Paraconcavus pacificus, red-striped acorn barnacle
• Semibalanus balanoides, northern acorn barnacle

References

1. Barnacle
2. Whale barnacle
3. Balanus nubilus
4. Amphibalanus improvisus
5. Semibalanus balanoides
6. Balanus glandula
7. Paraconcavus pacificus
8. Balanus
9. Chthamalus stellatus
10. Amphibalanus amphitrite
11. Pollicipes polymerus
12. Largest and heaviest animals
13. Megabalanus
14. Perforatus
15. Balanomorpha
16. Chthamalus montagui
17. Semibalanus cariosus
18. Chelonibia
19. Megabalanus coccopoma
20. Balanus balanus