Semibalanus balanoides
ARTHROPODA
Cirripedia
🌊 🪨Barnacles are everywhere! But have you ever wondered what they really looked like?
😱🌋They are scary, aren’t they?! Up close, these seemingly innocuous creatures look like miniature volcanoes, with a scary hand reaching out!
🦀 🦞As they have a hard exoskeleton, they are arthropods, related to crabs and lobsters. Adult barnacles are sessile animals, growing their shells directly onto the substrate.
🫴🪶Inside, barnacles hide a fascinating filter-feeding mechanism, using feathery appendages called cirri to sweep nutrients from the water.
🦐🌋The anatomy of the barnacle – as adults, represent a unique example of modified crustaceans, resembling a sessile “shrimp” affixed to rocky substrates. Their calcareous shell plates serves as both protection and anchorage.
💧🚪Sessile (fixed) animals in the intertidal zone have evolved strategies to combat desiccation between high tides, like these opercular plates that help them retain moisture. It’s all about survival skills!
➿🦶Ever wondered where the name 𝘊𝘪𝘳𝘳𝘪𝘱𝘦𝘥𝘪𝘢 comes from? It’s derived from the Latin words 𝘤𝘪𝘳𝘳𝘪𝘵𝘶𝘴 “curly” and 𝘱𝘦𝘥𝘪𝘴 from 𝘱𝘦𝘴 “foot”. Together, it means “curly-footed”, as a reference to the barnacle’s distinctive curled legs used in filter-feeding.
📚🙇 Charles Darwin wasn’t just about finches and evolution. He spent eight years studying barnacles (1846-1854), laying the groundwork for Cirripedia studies, and eventually influencing his groundbreaking theories of natural selection. Even the father of evolution had a barnacle phase!
Sources
- MarLIN – very complete page!
- Doris
- Jean Deutsch, Darwin and barnacles, Comptes Rendus Biologies, Volume 333, Issue 2 (2010), https://doi.org/10.1016/j.crvi.2009.11.009