1. Department of Chemistry and Faculty of Pharmacy, Rhodes University, Grahamstown, South Africa, National Centre for Aquatic Biodiversity & Biosecurity, National Institute of Water & Atmospheric Research Ltd, Auckland, New Zealand, Department of Zoology, University of Durban Westville, Durban, South Africa, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah 84112, and Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093-0212