... attractant by bioassay-guided fractionation and high-performance liquid chromatography, and chemically identified it as the free-amino acid l -tryptophan ( l -Trp). In the present study, levels of this ecologically meaningful compound were quantified in various abalone tissues, and in freshly spawned eggs...

...-tryptophan was the natural sperm attractant in H. rufescens . Eggs released L-tryptophan at concentrations that triggered both activation and chemotaxis in sperm, exhibiting significant activity at levels as low as 10 -8 mol l -1 . The D-isomer of tryptophan was inactive,showing that the sperm response...