My research interests focus on marine and freshwater crustaceans and other benthic macro-invertebrates, and range broadly across animal behavior, population dynamics, community ecology, taxonomy, systematics, biogeography, phylogeogaphy, and environmental sciences. I have been intensively studying the taxonomy of hermit crabs in the Indo-West Pacific area and found global patterns of diversity. The greatest diversity is seen in the Philippines, Malay Peninsula, and Australia, known as the Indo-Malayan center of maximum marine biodiversity, or the coral triangle, due to its large number of marine organisms. A distribution boundary of many species is found at the eastern edge of West Pacific (i.e. the East Pacific Barrier). Hotspots of speciation are found in peripheral areas of the Indo-West Pacific, including Japan, Hawaii, and the Red Sea.