Balanus glandula explained

Balanus glandula (commonly known as the North American acorn barnacle or common acorn barnacle) 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. They are commonly found in the upper intertidal zone on mussels, rocks and pier pilings.^[1] They can obtain oxygen from both water and air.^[2]

This acorn barnacle is a moderate-sized one with a diameter of up to 22mm.^[1] The shell is formed by overlapping plates and has a calcareous basis. It has more the shape of a cylinder than the shape of a cone. The white operculum has heavily ridged walls.^[1] It can live up to ten years.^[1]

It has been intensely studied in recent years as a model species for linking physical oceanography and population genetics (or phylogeography) surveys.^[3] This species was introduced to the shores of Argentina in the 1960s, and has become an invasive species, displacing other barnacles and mussels.^{[4] [5]}

Notes and References

1. Book: Robert Hugh Morris, Donald Putnam Abbott & Eugene Clinton Haderlie . 1980 . Intertidal Invertebrates of California . . Stanford . 978-0-8047-1045-9 . Balanus glandula . 520–521 . https://books.google.com/books?id=NAybxQZvWI0C&pg=PA520.
2. Web site: Balanus glandula - Overview . Rosario Beach Marine Laboratory . Rosario Beach Marine Laboratory . . 2018-08-15.
3. Erik Sotka . John Wares . Jack Barth . Rick Grosberg . Steve Palumbi . Steve Palumbi . 2004. Strong genetic clines and geographical variation in gene flow in the rocky intertidal barnacle Balanus glandula. Molecular Ecology. 13. 8. 2143–2156 . 10.1111/j.1365-294x.2004.02225.x. 15245390 . 18401309 .
4. Zaixso, H.E., Boraso de Zaixso, A.L., Pastor de Ward, C.T., Lizarralde, Z., Dadón, J.R. and Galván, D. 2015. Capítulo 2. El bentos costero patagónico. In: Zaixso, H.E., A.L. Boraso de Zaixso, C.T. Pastor de Ward, Z. Lizarralde, J.R. Dadón and D. Galván (Eds.), La Zona Costera Patagónica Argentina. Volumen II. Comunidades Biológicas y Geología, Editorial Universitaria de la Patagonia, Comodoro Rivadavia, pp. 43–152.
5. Evangelina Schwindt. 2007 . The invasion of the acorn barnacle Balanus glandula in the south-western Atlantic 40 years later . . 87 . 5 . 1219–1225 . 10.1017/S0025315407056895. 11336/103239 . free .