Phase reduction approach to elastohydrodynamic synchronization of beating flagella.

We formulate a theory for the phase reduction of a beating flagellum. The theory enables us to describe the dynamics of a beating flagellum in a systematic manner using a single variable called the phase. The theory can also be considered as a phase reduction method for the limit-cycle solutions in infinite-dimensional dynamical systems, namely, the limit-cycle solutions to partial differential equations representing beating flagella.

A new large tellinid species of the genus from the Ryukyu Archipelago, Japan (Mollusca, Bivalvia).

A new tellinid species, , is described from sand banks around Amami Islands, the Ryukyu Archipelago, in southern Japan. A molecular phylogenetic analysis suggests that this new species is closely related to . This species has long siphons and lives buried deep in well-sorted white sand syntopically with .

Substrate-borne vibrations induce behavioral responses in the leaf-dwelling cerambycid, Paraglenea fortunei.

Many insects utilize substrate-borne vibrations as a source of information for recognizing mates or predators. Among various substrates, plant leaves are commonly used for transmitting and receiving vibrational information. However, little is known about the utilization of vibrations by leaf-dwelling insects, especially coleopteran beetles.

A novel filtering mutualism between a sponge host and its endosymbiotic bivalves.

Sponges, porous filter-feeding organisms consisting of vast canal systems, provide unique substrates for diverse symbiotic organisms. The Spongia (Spongia) sp. massive sponge is obligately inhabited by the host-specific endosymbiotic bivalve Vulsella vulsella, which benefits from this symbiosis by receiving protection from predators.

Host specificity and population dynamics of a sponge-endosymbiotic bivalve.

We assessed the host-use pattern of the sponge-endosymbiotic bivalve Vulsella vulsella and its demographic consequences in an inland sea in Okinawa Island, Japan. Vulsella vulsella utilized only one massive globular sponge species Spongia sp. as a host, and no Spongia sp.

Pattern and process of diversification in an ecologically diverse epifaunal bivalve group Pterioidea (Pteriomorphia, Bivalvia).

The pterioid bivalves (superfamily Pterioidea) are epifaunal filter feeders that attach to various substrata, including rocks, corals, gorgonians, and sponges. An intriguing question is how different substratum types have affected the diversification of pterioid bivalves. To elucidate the evolutionary pathway of Pterioidea, we conducted a phylogenetic analysis of 49 individuals belonging to 18 pterioid and 5 outgroup species using 18S and 28S ribosomal RNA genes.