Large-scale genome sequencing reveals the driving forces of viruses in microalgal evolution

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Appetitive Responses to Computer-Generated Visual Stimuli by Female Rhombodera basalis, Deroplatys lobata, Hierodula membranacea, and Miomantis sp. (Insecta: Mantodea)

We used computer-generated stimuli to assess the stimulus parameters eliciting prey-directed behaviors in four mantis species: Rhombodera basalis (60 mm body length), Deroplatys lobata (70 mm), Hierodula membranacea (80 mm), Miomantis sp (38 mm). All responded appetitively to erratically moving disks subtending 10° or more. R. basalis responded more consistently to checkered (versus solid black) disks; only D. lobata displayed a size preference (14–23 deg disks); Miomantis sp. struck at disks as large as did the largest species; only Miomantis sp. displayed approaching behavior. H. membranacea and R. basalis preferred black disks on a white background (versus the reverse), and red disks (versus blue or green) on a brightness-matched grey background. All preferred elongated stimuli moving parallel (versus perpendicular) to their long axes.     

Seasonal patterns of growth and nutrient status of the macroalga Adamsiella chauvinii (Rhodophyta) in soft sediment environments

The seasonal growth and nutrient status of the temperate subtidal macroalga Adamsiella chauvinii was determined at three soft sediment sites with different ranges of tidally-driven current speeds. A. chauvinii thalli exhibited maximum growth rates during the late summer (February) and no evidence of nitrogen limited growth in summer as often exhibited by macroalgae growing on hard substrata in temperate environments. We suggest that growth was maintained during the summer period, when seawater nitrogen concentrations were low, by localized sources of ammonium probably produced by sediments and fauna within the canopy. Growth rates were up to 50% lower at the site with the slowest water velocity throughout most of the experimental period. However a greater tissue nitrogen content of A. chauvinii thalli at the slow flow site did not support evidence for mass-transfer limitation. It is suggested that as a consequence of slow flow, sedimentation on blade surfaces reduced the amount of light available for photosynthesis and growth. Lower growth rates at the slow flow site reduced metabolic demand for nutrients resulting in accumulation of tissue nitrogen and phosphate.