Adult specimens of Chthamalus fragilis Darwin were removed carefully from the leaves and stalks of marsh grass and placed with their bases on the bottoms of polystyrene dishes containing sea water in order to allow reattachment of the animals. During overnight culture, animals secreted small volumes of a sea water-insoluble material which reattached the animals to the surface of the polystyrene dishes. The secreted material made a contact angle with the polystyrene surface of ∼ 15°, indicating that, before "setting," the liquid precursor of the "set" material has considerable wetting properties. Dishes with reattached barnacles were mounted in a centrifuge to load the animals in shear and were subjected to increasing speeds of rotation until each of the reattached barnacles became detached. Reattached barnacles sustained relative centrifugal forces of up to 6,800 x g before detachment, which usually occurred at the barnacle basis/ cement interface. The strength of adhesion of individual barnacles reattached to polystyrene ranged from 0.0014―0.3589 Newtons. Using the area of attachment between cement and polystyrene dish, the strength of adhesion averaged 1.05 × 105 Nm–2, with a range of 0.14 × 105 to 2.79 × 105 Nm–2. These data are comparable to forces of adhesion reported for the temporary attachment of cyprid larvae and the normal attachment of adult barnacles to plastics and other materials measured by techniques which load the animals in tension. Our observations and measurements indicate that the material secreted by adult barnacles under in vitro culture conditions exhibits significant adhesive properties. It is unlikely that adult barnacles detached from marsh grass reattach to polystyrene by Stefan effects.
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William J. Dougherty (1990) studied this question.