Genotype × genotype interactions between the toxic cyanobacterium Microcystis and its grazer, the waterflea Daphnia

Abstract

Toxic algal blooms are an important problem worldwide. The literature on toxic cyanobacteria blooms in inland waters reports widely divergent results on whether zooplankton can control cyanobacteria blooms or cyanobacteria suppress zooplankton by their toxins. Here we test whether this may be due to genotype × genotype interactions, in which interactions between the large-bodied and efficient grazer Daphnia and the widespread cyanobacterium Microcystis are not only dependent on Microcystis strain or Daphnia genotype but are specific to genotype × genotype combinations. We show that genotype × genotype interactions are important in explaining mortality in short-time exposures of Daphnia to Microcystis. These genotype × genotype interactions may result in local coadaptation and a geographic mosaic of coevolution. Genotype × genotype interactions can explain why the literature on zooplankton–cyanobacteria interactions is seemingly inconsistent, and provide hope that zooplankton can contribute to the suppression of cyanobacteria blooms in restoration projects.

Clonal Variation in Growth Plasticity within a Bosmina longirostris Population: The Potential for Resistance to Toxic Cyanobacteria

“…This large variation in resistance to cyanobacteria in bosminids not only confirms previous studies reporting genetic differences in resistance among Daphnia clones from different populations [8,22,34,35], but also demonstrates that substantial clonal variation can occur within a population since our bosminid clones were randomly isolated from one zooplankton sample. Given that M .…”

Setae thickening in Daphnia magna alleviates the food stress caused by the filamentous cyanobacteria

“…Perhaps, clonal variation in response to food stress caused by cyanobacterial filaments was due to a different history of examined clones. Many previous studies have shown that Daphnia genotypes experienced with cyanobacteria in the past can have a greater performance at the next encounter with cyanobacteria in comparison with not experienced genotypes (Lemaire et al 2012;Chislock et al 2013). Although we cannot be sure whether our clones had contact with filamentous cyanobacteria before they have been acquired, the ponds where the Wilson and Zoot clones originate from never-experienced cyanobacterial blooms.…”

A quantitative protocol for rapid analysis of cell density and size distribution of pelagic and benthic Microcystis colonies by FlowCAM

“…However, Microcystis forms colonies under natural conditions, which must be disintegrated before enumeration. Typical techniques for disintegrating Microcystis colonies are sonication (Asai et al 2000;Briand et al 2009;Kurmayer et al 2003;Zhou et al 2012), alkaline hydrolysis (Janse et al 2004;Kardinaal et al 2007;Reynolds and Jaworski 1978), and heating/boiling (Chaffin et al 2011;Joung et al 2006;Lemaire et al 2012;Zohary and Madeira 1987).…”