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The interactive effects of ammonia and microcystin on life-history traits of the cladoceran Daphnia magna: synergistic or antagonistic?

Yang Z, Lü K, Chen Y, Montagnes DJ - PLoS ONE (2012)

Bottom Line: The occurrence of Microcystis blooms is a worldwide concern that has caused numerous adverse effects on water quality and lake ecology.Interactive effects of the toxins occurred for five traits: the time to first batch of eggs appearing in the brood pouch, time to first clutch, size at first clutch, number of clutches, and total offspring per female.In conclusion, the released toxins during the degradation of Microcystis blooms would result, according to our data, in substantially negative effect on D. magna.

View Article: PubMed Central - PubMed

Affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, Nanjing, China.

ABSTRACT
The occurrence of Microcystis blooms is a worldwide concern that has caused numerous adverse effects on water quality and lake ecology. Elevated ammonia and microcystin concentrations co-occur during the degradation of Microcystis blooms and are toxic to aquatic organisms; we studied the relative and combined effects of these on the life history of the model organism Daphnia magna. Ammonia and microcystin-LR treatments were: 0, 0.366, 0.581 mg L(-1) and 0, 10, 30, 100 µg L(-1), respectively. Experiments followed a fully factorial design. Incubations were 14 d and recorded the following life-history traits: number of moults, time to first batch of eggs, time to first clutch, size at first batch of eggs, size at first clutch, number of clutches per female, number of offspring per clutch, and total offspring per female. Both ammonia and microcystin were detrimental to most life-history traits. Interactive effects of the toxins occurred for five traits: the time to first batch of eggs appearing in the brood pouch, time to first clutch, size at first clutch, number of clutches, and total offspring per female. The interactive effects of ammonia and microcystin appeared to be synergistic on some parameters (e.g., time to first eggs) and antagonistic on others (e.g., total offspring per female). In conclusion, the released toxins during the degradation of Microcystis blooms would result, according to our data, in substantially negative effect on D. magna.

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Size at first clutch.Effect of ammonia under different microcystin-LR concentrations (a–d) and the effect of microcystin-LR under different ammonia concentrations (e–g) on size at first clutch. Error bars indicate 1 SE, and different letters denote significant difference at P<0.05.
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pone-0032285-g005: Size at first clutch.Effect of ammonia under different microcystin-LR concentrations (a–d) and the effect of microcystin-LR under different ammonia concentrations (e–g) on size at first clutch. Error bars indicate 1 SE, and different letters denote significant difference at P<0.05.

Mentions: The size at first eggs was significantly affected by ammonia and microcystin (Table 1). In general, size at first eggs increased with increasing microycstin concentration (Figure 4e–g), but the effect of ammonia on size at first eggs was irregular (Figure 4a–d). Surprisingly, size at first clutch significantly decreased under high ammonia and high microcystin (Figure 5a,e) but remained unchanged under mixed toxins with high concentrations (Figure 5d,g), indicating significant interactive effect of ammonia and microcystin on size at first clutch (Table 1).


The interactive effects of ammonia and microcystin on life-history traits of the cladoceran Daphnia magna: synergistic or antagonistic?

Yang Z, Lü K, Chen Y, Montagnes DJ - PLoS ONE (2012)

Size at first clutch.Effect of ammonia under different microcystin-LR concentrations (a–d) and the effect of microcystin-LR under different ammonia concentrations (e–g) on size at first clutch. Error bars indicate 1 SE, and different letters denote significant difference at P<0.05.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3293791&req=5

pone-0032285-g005: Size at first clutch.Effect of ammonia under different microcystin-LR concentrations (a–d) and the effect of microcystin-LR under different ammonia concentrations (e–g) on size at first clutch. Error bars indicate 1 SE, and different letters denote significant difference at P<0.05.
Mentions: The size at first eggs was significantly affected by ammonia and microcystin (Table 1). In general, size at first eggs increased with increasing microycstin concentration (Figure 4e–g), but the effect of ammonia on size at first eggs was irregular (Figure 4a–d). Surprisingly, size at first clutch significantly decreased under high ammonia and high microcystin (Figure 5a,e) but remained unchanged under mixed toxins with high concentrations (Figure 5d,g), indicating significant interactive effect of ammonia and microcystin on size at first clutch (Table 1).

Bottom Line: The occurrence of Microcystis blooms is a worldwide concern that has caused numerous adverse effects on water quality and lake ecology.Interactive effects of the toxins occurred for five traits: the time to first batch of eggs appearing in the brood pouch, time to first clutch, size at first clutch, number of clutches, and total offspring per female.In conclusion, the released toxins during the degradation of Microcystis blooms would result, according to our data, in substantially negative effect on D. magna.

View Article: PubMed Central - PubMed

Affiliation: Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, Nanjing, China.

ABSTRACT
The occurrence of Microcystis blooms is a worldwide concern that has caused numerous adverse effects on water quality and lake ecology. Elevated ammonia and microcystin concentrations co-occur during the degradation of Microcystis blooms and are toxic to aquatic organisms; we studied the relative and combined effects of these on the life history of the model organism Daphnia magna. Ammonia and microcystin-LR treatments were: 0, 0.366, 0.581 mg L(-1) and 0, 10, 30, 100 µg L(-1), respectively. Experiments followed a fully factorial design. Incubations were 14 d and recorded the following life-history traits: number of moults, time to first batch of eggs, time to first clutch, size at first batch of eggs, size at first clutch, number of clutches per female, number of offspring per clutch, and total offspring per female. Both ammonia and microcystin were detrimental to most life-history traits. Interactive effects of the toxins occurred for five traits: the time to first batch of eggs appearing in the brood pouch, time to first clutch, size at first clutch, number of clutches, and total offspring per female. The interactive effects of ammonia and microcystin appeared to be synergistic on some parameters (e.g., time to first eggs) and antagonistic on others (e.g., total offspring per female). In conclusion, the released toxins during the degradation of Microcystis blooms would result, according to our data, in substantially negative effect on D. magna.

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