There are three major research focuses in our lab:
・Body plan evolution in deuterostomes
・Evolution of metazoan development patterns
・Diversity of marine invertebrate development
Below are the ongoing projects:
Placozoa is an amoebae-like marine flat animal about 0.5-2mm in diameter, possessing one of the simplest body plans within the metazoans. It lacks tissues or organs, and does not possess neurons or muscle cells. Since the simple body plan may represent the ancestral state of metazoans, intensive phylogenetic analyses have been done on the animal. However, its sperm and development still remain a mystery. We have discovered Placozoans at Shimoda Marine Research Center in 2010. We are studying the morphology, ecology, and phylogeny of Shimoda Placozoans, with aims of observing its development and establishing lab cultures.
Xenoturbella is a strange worm–like marine animal about 1 cm long, lacking typical bilaterian traits such as an anus, gonads, coelomic cavities, and brain. Due to this simple body plan, their phylogenetic position was long obscure. Since 2004, I have being studying the development, phylogeny, morphology, and ecology of Xenoturbella. Together with collaborators, we reported in 2011 that Xenoturbella and acoelomorpha, (another simple worm) forms a new phylum within the deuterostomes. Regular collections of the animal are currently only possible in Sweden, but there are reports from other parts of the world and we hope to find Xenoturbella in Japan.
３．Diversity of Marine Invertebrate Development
Almost all living phyla possess species that have marine plaktonic larva, and a typical larva is known for most animal groups. However, these ‘typical’ larvae are sometimes speculated from just a few species, and there are many species whose development remains unknown. We hope to uncover the development of these less studied animals, and by comparing the development patterns with other species, we aim to uncover the diversity in marine invertebrate development and to gain new information on the ancestor and evolution of metazoans and deuterostomes.
Sagami Bay and Suruga Bay is known to be one of the most biodiversity rich seas in the world, and countless species of animals can be collected at Shimoda Marine Research Center. We hope to perform many other experiments on various animals as well.