Editing Barnacle (section)

=== Species-specific zones ===

Although they have been found at water depths to {{convert|600|m|ft|-2|abbr=on}},<ref name=Doyle1997/> most barnacles inhabit shallow waters, with 75% of species living in water depths less than {{convert|100|m|ft|-2|abbr=on}},<ref name=Doyle1997/> and 25% inhabiting the [[intertidal zone]].<ref name=Doyle1997/> Within the intertidal zone, different species of barnacles live in very tightly constrained locations, allowing the exact height of an assemblage above or below sea level to be precisely determined.<ref name=Doyle1997/>

Since the intertidal zone periodically [[Desiccation|desiccates]], barnacles are well adapted against water loss. Their calcite shells are impermeable, and they can close their apertures with movable plates when not feeding.<ref name="Buckeridge 2012">{{cite journal |last=Buckeridge |first=John S. |title=Opportunism and the resilience of barnacles (Cirripedia: Thoracica) to environmental change |journal=Integrative Zoology |volume=7 |issue=2 |date=2012 |issn=1749-4877 |doi=10.1111/j.1749-4877.2012.00286.x |pages=137–146|pmid=22691197 }}</ref> Their hard shells are assumed by zoologists to have evolved as an [[anti-predator adaptation]].<ref name="Zimmer Ferrier Zimmer 2021">{{cite journal |last1=Zimmer |first1=Richard K. |last2=Ferrier |first2=Graham A. |last3=Zimmer |first3=Cheryl Ann |title=Chemosensory Exploitation and Predator-Prey Arms Races |journal=Frontiers in Ecology and Evolution |volume=9 |date=2021-11-12 |issn=2296-701X |doi=10.3389/fevo.2021.752327 |doi-access=free |page=}}</ref>

One group of stalked barnacles has adapted to a rafting lifestyle, drifting around close to the water's surface. They colonize every floating object, such as driftwood, and like some [[Acorn barnacle|non-stalked barnacles]] attach themselves to marine animals. The species most specialized for this lifestyle is ''[[Dosima fascicularis]]'', which secretes a gas-filled cement that makes it float at the surface.<ref>{{Cite journal |last1=Zheden |first1=Vanessa |last2=Kovalev |first2=Alexander |last3=Gorb |first3=Stanislav N. |last4=Klepal |first4=Waltraud |date=2015-02-06 |title=Characterization of cement float buoyancy in the stalked barnacle Dosima fascicularis (Crustacea, Cirripedia) |journal=[[Interface Focus]] |volume=5 |issue=1 |pages=20140060 |doi=10.1098/rsfs.2014.0060 |pmc=4275874 |pmid=25657839}}</ref>