# Northern Acorn Barnacle

*Semibalanus balanoides*

Barnacles glue themselves head-down to rocks using a natural cement so powerful that scientists still struggle to replicate its strength.

- **Taxonomy:** Animalia › Arthropoda › Hexanauplia › Balanomorpha › Balanidae › Semibalanus
- **IUCN Red List status:** Least Concern
- **Population trend:** stable
- **Biome:** aquatic
- **Habitat:** Rocky intertidal zones of cold temperate and polar seas.
- **Diet:** Plankton and organic detritus filtered from seawater.
- **Range:** North Atlantic Ocean, North Sea, Arctic Ocean, Pacific Coast of North America
- **Size:** Up to 15 mm in diameter
- **Lifespan:** 3-6 years
- **Active:** diurnal
- **Threats:** Ocean acidification, rising sea surface temperatures, and coastal development.
- **Safe to approach?:** Harmless, but their calcium carbonate shells are razor-sharp. Wear thick-soled water shoes when walking on rocky shores to avoid painful cuts. If scratched, wash the wound thoroughly with clean water and apply antiseptic to prevent marine bacterial infection.

## About

Semibalanus balanoides is a common and widespread boreo-arctic species of acorn barnacle. It is common on rocks and other substrates in the intertidal zone of north-western Europe and both coasts of North America.

## Sources

- Plate: https://gaia-dex.com/species/bca6b4f7-8bb9-41f0-9203-d144e741289a
- iNaturalist: https://www.inaturalist.org/taxa/118832
- Wikipedia: https://en.wikipedia.org/wiki/Semibalanus balanoides
- Conservation status: IUCN Red List category, as recorded by Gaia-Dex
- Photo: https://inaturalist-open-data.s3.amazonaws.com/photos/41373988/medium.jpeg (hitchco, CC0, via iNaturalist)

Habitat, diet, size and similar notes are AI-written summaries; check them against the linked sources before relying on them.