Inhibition of barnacle settlement and behavior by natural products from whip corals,Leptogorgia virgulata (Lamarck, 1815).

Laboratory-reared barnacle larvae were used to study natural products from whip corals. Biological assays used barnacle responses in behavioral assays and in larval settlement assays. Whip corals contained substances that were active in both assays. Substances inhibiting swimming and reversible attachment of barnacle larvae were found in an aqueous extract of whip corals. Low-molecular-weight substances inhibiting barnacle settlement were found in a methylene chloride extract of material soluble in aqueous methanol. Antisettlement activity was associated with substances with specific mobilities in several chromatography systems. Partially purified material was effective in preventing settlement at concentrations of less than 0.2 μ/ml. Settlement inhibition involves adsorption of the natural product to surfaces.