Reproductive allocation in Daphnia exposed to toxic cyanobacteria
| Autor: | Mari Walls, Jaana Hietala, Marko Reinikainen |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Avian clutch size
Ecology biology Offspring media_common.quotation_subject Branchiopoda Aquatic Science biology.organism_classification Daphnia pulex Daphnia Animal science Cladocera Microcystis aeruginosa Reproduction reproductive and urinary physiology Ecology Evolution Behavior and Systematics media_common |
| Zdroj: | Journal of Plankton Research. 21:1553-1564 |
| ISSN: | 1464-3774 |
| DOI: | 10.1093/plankt/21.8.1553 |
| Popis: | We investigated experimentally how resources were allocated to reproduction in Daphnia pulex and Daphnia longispina when varying levels of toxic Microcystis were added to higher quality food. We used multiple regression models to estimate mean offspring size and clutch size in relation to maternal size and clutch number, and analysed effects of treatments on residuals from the models. We also measured variation in per offspring investment. At a high cyanobacterial level, D.pulex was virtually unable to reproduce. At a lower level, D.pulex produced small clutches. However, the regres- sion model residuals indicated that the presence of cyanobacteria increased the portion of available resources allocated to reproduction. The observed allocation may be a means to maximize repro- duction under diminished longevity. Effects on mean offspring size were marginal in D.pulex, but variation in per offspring investment sometimes decreased in cyanobacterial exposures. Daphnia longispina was affected by a higher cyanobacterial level only, where offspring size was reduced. Devi- ations from the regression model indicated that effects on maternal size alone do not explain this effect. Clutch size residuals and per offspring investment were unaffected by treatments in D.longispina. The observed responses differ from theoretical models on reproductive allocation under food limitation. |
| Databáze: | OpenAIRE |
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