Effects of Microcystis aeruginosa on population dynamics and sexual reproduction in two Daphnia species

Effects of colonialMicrocystis aeruginosaand interspecific competition on the population dynamics and resting egg formation of two cladocerans

“…Thus, more than 90% of the ephippia contained resting eggs. By contrast, for D. carinata, sexual females had difficulty mating with the males when the male percentage was low (Deng et al 2010), which increased the frequency of empty ephippia. Moreover, the per capita cumulative ephippia of D. carinata in the single-species culture was higher than that in the mixed culture at higher colonial M. aeruginosa biomass (M10).…”

“…Jarvis et al (1987) found that Daphnia pulex feeds on 60-100 mm Microcystis colonies, whereas 100-150 mm Microcystis colonies could not be digested and utilized. Although lower colonial Microcystis biomass did not significantly inhibit the population growth of D. carinata, D. carinata could not complete their growth and development in the presence of higher colonial Microcystis biomass (Chen et al 2007;Deng et al 2010;Dai & Chen 2012).…”

“…Colonial M. aeruginosa interferes with the feeding of Daphnia, decreasing their filtering rates (Gliwicz & Siedlar 1980;Jarvis et al 1987;Hessen & Donk 1993) and affecting their growth and reproduction (Tillmanns et al 2008;Deng et al 2010;Ferrão-Filho & Kozlowsky-Suzuki 2011). However, the toxic or inhibitory effect of colonial M. aeruginosa is less on small cladocerans (Fulton & Paerl 1987).…”

“…Under worsening environmental conditions, such as during inhibition by colonial Microcystis or in the presence of interspecific competition, the reproductive mode of cladocerans changes from parthenogenesis to sexual reproduction to produce resting eggs (Carvalho & Hughes 1983;Deng et al 2009;Smith et al 2009). Although the effects of cyanobacteria on the population dynamics and competitive outcomes of cladocerans have been extensively investigated (Fulton & Paerl 1988;DeMott 1989;Chen & Xie 2003;Chen et al 2007;Deng et al 2008), little attention has been given to the influence of colonial Microcystis aeruginosa on the ephippium production and resting egg formation of two Daphnia species in single-species cultures (Deng et al 2010). Moreover, the mechanism by which colonial Microcystis triggers the sexual reproduction of cladocerans in mixed cultures remains unclear.…”

Combined effects of colonial size and concentration ofMicrocystis aeruginosaon the life history traits ofDaphnia similoides

“…Many previous investigations had indicated that the body length of Daphnia declined with increased M. aeruginosa concentrations [7,9,18], including the body length at maturity [13,21,25]. Cerbin et al [4] found also that increasing microcystin concentrations significantly reduced the body length at first reproduction of D. pulicaria.…”