Balanus glandula is one of the most common barnacle species on the Pacific coast of North America, distributed from the U.S. state of Alaska to Bahía de San Quintín near San Quintín, Baja California. It is commonly found in intertidal waters on mussels, rocks and pier pilings.
It is a moderate-sized barnacle with a diameter of up to 22 mm (0.9 in). The shell is formed by overlapping plates. It is has more the shape of a cylinder than the shape of a cone. The white operculum has heavily ridged walls. It can live up to ten years.
It has been intensely studied in recent years as a model species for linking physical oceanography and population genetics (or phylogeography) surveys. This species was introduced to the shores of Argentina in the 1970s, and has become an invasive species, displacing other barnacles and mussels.
- Robert Hugh Morris, Donald Putnam Abbott & Eugene Clinton Haderlie (1980). "Balanus glandula". Intertidal Invertebrates of California. Stanford: Stanford University Press. pp. 520–521. ISBN 978-0-8047-1045-9. http://books.google.com/books?id=NAybxQZvWI0C&pg=PA520.
- Evangelina Schwindt (2007). "The invasion of the acorn barnacle Balanus glandula in the south-western Atlantic 40 years later". Journal of the Marine Biological Association of the United Kingdom 87 (5): 1219–1225. doi:10.1017/S0025315407056895.