Do early life history characteristics determine species ranges and dispersal of coral reef fishes in the Indo‐Pacific?

The Indo‐Pacific consists of extensive continuous coastlines and many island groups of varying sizes and isolation. The species ranges of coral reef fishes vary enormously from Indo‐Pacific wide to highly endemic. There is also great variation in the early life history characteristics of coral reef fishes ( e.g . pelagic larval durations, spawning strategies and swimming abilities). We use individual‐based models (IBMs) to simulate the dispersal of coral reef fishes in the Indo‐Pacific. The development of dispersal strategies is explored based on ecological and geographical constraints. Simulations are presented for climatic and anthropogenically‐induced events.     

Genbank accession #: AF111812

Plant Molecular Biology -     

Effects of growth rate and methotrexate on folate polyglutamates and folylpolyglutamate hydrolase activity in Krebs ascites cells

The activity of folylpolyglutamate hydrolase was measured throughout intraperitoneal growth of Krebs ascites cells in mice and after exposure to methotrexate. Hydrolase activity was lowest during the log phase of growth. Methotrexate administered intraperitoneally during log growth caused a dose- and time-dependent increase in hydrolase activity. Modest changes were observed in endogenous folate polyglutamate chain length distributions throughout growth and upon exposure to methotrexate, but these changes could not be correlated with hydrolase activity.     

Glucose Transport in Stationary-Phase Cultures of an Asporogenous Strain of Bacillus licheniformis

The sporulation-deficient industrial organism Bacillus licheniformis HWL10 possesses two distinct glucose transport systems in log-phase cells, a glucose phosphotransferase system (PTS) and a non-PTS mechanism. The strain continues to take up glucose at a significant though reduced rate during prolonged stationary-phase incubation, but only the PTS is active.     

Diversity and biomass dynamics of unicellular marine fungi during a spring phytoplankton bloom

Microbial communities have important functions during spring phytoplankton blooms, regulating bloom dynamics and processing organic matter. Despite extensive research into such processes, an in-depth assessment of the fungal component is missing, especially for the smaller size fractions. We investigated the dynamics of unicellular mycoplankton during a spring phytoplankton bloom in the North Sea by 18S rRNA gene tag sequencing and a modified CARD-FISH protocol. Visualization and enumeration of dominant taxa revealed unique cell count patterns that varied considerably over short time scales. The Rozellomycota sensu lato (s.l.) reached a maximum of 10⁵ cells L⁻¹, being comparable to freshwater counts. The abundance of Dikarya surpassed previous values by two orders of magnitude (10⁵ cells L⁻¹) and the corresponding biomass (maximum of 8.9 mg C m⁻³) was comparable to one reported for filamentous fungi with assigned ecological importance. Our results show that unicellular fungi are an abundant and, based on high cellular ribosome content and fast dynamics, active part of coastal microbial communities. The known ecology of the visualized taxa and the observed dynamics suggest the existence of different ecological niches that link primary and secondary food chains, highlighting the importance of unicellular fungi in food web structures and carbon transfer.