Comparative biology of deep-sea shelly invertebrates

点击翻译按钮获取中文摘要

Various important knowledge has been obtained about the comparative biology of marine shelly invertebrates (Bivalvia, Gastropoda, Cephalopoda, . Ostracoda and Crinoidea) which well in deep-water and cryptic environments (22 papers and 20 oral presentations).Hayami and Kase found a rich molluscan assemblage in several submarine caves of Ie-jima and Shimoji-jima in Ryukyu, and its uniqueness in morphology, ecology and development was clarified with assistance of skilled divers. This fauna contains "living fossil". genera, Neritopsis and Pycnodonte, and numerous minute molluscs which are surprisingly similar to deep-sea faunas in generic assemblage and developmental strategy. The predominance of paedomorphosis and K-selection in cave molluscs is very interesting for the test of some general theories and models in evolutionary ecology.Hayami clarified the airfoil function of streamlined pectinid shells by hydrodynamic experiments. -Tanabe studied early development and larval ecology of bivalves (Limopsidae), and also obtained various new knowledge about the early ontogeny and functional morphology of ammonites and living Nautilus. Abe examined sexual behavior of an ostracod using video and clarified the function of limbs. Oji described Miocene crinoids in Japan, and cultured living crinoid, obtaining much information about their ecology, functional morphology, autotomy regeneration of arms.