1,738 publications from this institution
Organisms have evolved the ability to manipulate light for vision, as a means to capture its energy, to protect themselves from damage, especially against ultraviolet (UV) and other high flux radiation, and for display purposes. The makeup of the structural elements used for this manipulation often discloses novel pathways for man-made photonic devices. Iridocytes in the mantle of giant clams in the Tridacninae subfamily manipulate light in many ways, e.g., as reflectors, scattering centers, and diffusers. There is, however, a void in understanding the absorption and photoluminescence (PL) emission dynamics of these cells. In turn, a profound understanding of iridocytes’ photophysics can offer the prospect for a new generation of advanced optoelectronic materials and devices. Here, the structural and optical properties of the iridocytes embedded in the mantle tissue of the Tridacna maxima are investigated and their use as a high-speed color convertor for UV photodetection, well-suited to application in UV optical wireless communication, is demonstrated.
The deep scattering layer (DSL) is a ubiquitous acoustic signature found across all oceans and arguably the dominant feature structuring the pelagic open ocean ecosystem. It is formed by mesopelagic fishes and pelagic invertebrates. The DSL animals are an important food source for marine megafauna and contribute to the biological carbon pump through the active flux of organic carbon transported in their daily vertical migrations. They occupy depths from 200 to 1000 m at daytime and migrate to a varying degree into surface waters at nighttime. Their daytime depth, which determines the migration amplitude, varies across the global ocean in concert with water mass properties, in particular the oxygen regime, but the causal underpinning of these correlations has been unclear. We present evidence that the broad variability in the oceanic DSL daytime depth observed during the Malaspina 2010 Circumnavigation Expedition is governed by variation in light penetration. We find that the DSL depth distribution conforms to a common optical depth layer across the global ocean and that a correlation between dissolved oxygen and light penetration provides a parsimonious explanation for the association of shallow DSL distributions with hypoxic waters. In enhancing understanding of this phenomenon, our results should improve the ability to predict and model the dynamics of one of the largest animal biomass components on earth, with key roles in the oceanic biological carbon pump and food web.
