**5. Conclusions**

The Australian Muricidae *D. orbita* biosynthesizes a range of biologically active secondary metabolites, which have stimulated extensive biological and chemical investigations since the 1960s. Early research focused on the identification of the precursors to the well known ancient dye Tyrian purple, and revealed an interesting association between these brominated indole precursors and choline esters. The muscle-relaxant and neurotoxic activity of Muricidae choline esters has been well described in the literature and more recent research has focused on the anticancer properties of the brominated

indoles. Despite significant research interest, the ecological and physiological role of the Tyrian purple precursors remains uncertain. However, the combination of biologically active compounds present in *D. orbita* provides interesting potential for nutraceutical development. Increasing biological knowledge on the ecology of the snail, as well as the biodistribution and biosynthesis of secondary metabolites in this species will facilitate sustainable supply. These biological and chemical insights on *D. orbita* provide a good basis for future research and position this species as a suitable model system for novel method development and other innovative research in marine natural product chemistry.

**Acknowledgments:** Support from the Marine Ecology Research Centre, Southern Cross University and School of Biological Sciences, Flinders University is much appreciated. I would like to thank all of the postgraduate research students and collaborators who have contributed to my research program on *D. orbita* over the last 10 years, my original Ph.D. advisors Andy Davis and John Bremner at the University of Wollongong where this research began, as well as Joe Baker for his inspiration and personal insights on *D. orbita*.
