Larvotoxic extracts of the hard coral Goniopora tenuidens: allelochemicals that limit settlement of potential competitors?

Aqueous extracts of Goniopora tenuidens inhibited larval metamorphosis and post-metamorphic growth of the hard coral Pocillopora damicornis. The extracts killed swimming larvae of four scleractinian corals and modified the behaviour of larvae of P. damicornis at concentrations as low as 3.9 micrograms ml-1. This toxicity may indicate the presence of allelochemicals that limit the settlement of potential competitors.