Research activies of the Research Program for Marine Biology and Ecology from 2004 to 2008.

Abstract

In 2004, a department of JAMSTEC, Marine Ecosystem Rearch Division, was reorganized and the Research Program for Marine Biology and Ecology was established as one of research programs in the Extremobiosphere Research Center (XBR). This review describes the research activities in this program. In the last 5 years, we have conducted two research projects, Symbisis and Evolution of Marine Organisms Research Project and Marine Ecosystem Research Project. In the former project, we have studied genome of the chemoautotrophic symbiotic bacterium of Calyptogena okutanii (a deep-sea symbiotic clam), and comparative genome analysis of Calyptogena clam symbionts. We have also studied symbiotic mytiliid clams found in whale-fall animal communities, symbiosis found in foraminifers and some other symbiotic systems. These studies have opened a way to address questions not only in mechanisms underling the deep-sea chemoautotrophic sysmbiosis, but also in the origin of eukaryotic organelles. In the latter research project, we have studied plankton and benthos. In the plankton research, we have quantitatively analyzed vertical distribution of animal plankters, diurnal/seasonal changes of their distributions and biomasses, and their contribution to the biological pump (downward transport of organic carbons) in marine ecosystems. We have also studied deep-sea dwelling jellyfishes, their lifecycles and interaction with other organisms, such as mollusks and crustaceans. For future research on the global marine ecosystems, we have developed an AUV (Autonomous Unverwater Vehicle), which can equip with a highdefinition TV camera and/or a VPR (Visual Plankton Recorder). These researches are expected to contiribute to the future marine ecosystem ecology, which is becoming more and more important to overcome the global warming on our planet. In the research of benthos, we have studied growth and distribution of some benthic animals. Spawning of a deep-sea Calyptogena clam has been studied in detail by using a dee-sea observatory system in Sagami-bay. In the research of diversities in benthic organisms, we have investigated various organisms from protists (unicellular eukaryotes) to multicellular animals. These studies will contribute to understanding the biodiversity on the earth. Biological rerearch on deep-sea animals is hampered by difficulties of rearing them in laboratories. We have tried to develop rearing techniques of deep-sea animals in collaboration with Shin-Enoshima Aquarium. We have also found that half decomposed whale bones provide a suitable substratum for many deep-sea symbiotic animals. These techniques seem to be promising to establish the long term rearing technique of deep-sea animals. Since the establishment of JAMSTEC, scientists have reported many new species of deep-sea animals around Japan. However, there had been no textbook of deep-sea biology in Japan. In 2008, we published a textbook of deep-sea biology with many pictures of those animals in situ. We extend this line of out-reach to develop a database of deep-sea animals in 2009. We have also published a children's book of deep-sea living world. We hope that these books will draw attentions for general public and for young children who will become biologists to study deep-sea life in the future.
In this review, we also describe our studies on subjects other than the program researches. They are biology of piazophiles, biochemistry of chaperonin in a hyperthomophile, and comparative immunology of marine mammals.