First evidence of "paralytic shellfish toxins" and cylindrospermopsin in a Mexican freshwater system, Lago Catemaco, and apparent bioaccumulation of the toxins in "tegogolo" snails (Pomacea patula catemacensis).

Exposure to cyanobacterial toxins in freshwater systems, including both direct (e.g., drinking water) and indirect (e.

Cell volume distribution dynamics of Chlorella vulgaris Beij. in batch cultures under continuous light.

Cell volume distribution in Chlorella vulgaris cultures coming out of senescence was measured by flow cytometry every 6 h for 114 h in a full-factorial experiment with initial nitrate (420-4200 microg NO3-N l(-1)), phosphate (9-186 microg PO4-P l(-1)), and continuous light (50-330 microE m(-2) s(-1)) as treatments. The maxima in median and median absolute deviation (MAD) of cell volume were achieved within 6 h of each other and their timing was not affected by any treatment. Population specific growth rate during the first 66 h calculated from volume distribution changes was significantly affected by light treatment only (p=0.