Optimal light conditions for Daphnia filtration
Daphnia populations are present in lakes and ponds. They are known to experience diurnal vertical migrations according to their feeding needs. During the day they migrate downwards to avoid predation in light-receiving layers and at night they migrate upwards, searching for food in the shallow produ...
| Autores: | , , , , , |
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| Tipo de documento: | artigo |
| Estado: | Versión aceptada para publicación |
| Data de publicação: | 2019 |
| País: | España |
| Recursos: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repositório: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:10256/18726 |
| Acesso em linha: | http://hdl.handle.net/10256/18726 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Daphnia magna Aigües residuals -- Depuració -- Tractament biològic Sewage -- Purification -- Biological treatment Aigua -- Depuració -- Filtració Water -- Purification -- Filtration |
| Resumo: | Daphnia populations are present in lakes and ponds. They are known to experience diurnal vertical migrations according to their feeding needs. During the day they migrate downwards to avoid predation in light-receiving layers and at night they migrate upwards, searching for food in the shallow productive layers. The light photoperiod and light intensity vary depending on the latitude and, therefore, the precise location of lakes and ponds will be an additional and crucial parameter in determining the development of Daphnia. Here we will focus on a population of Daphnia magna (a genus of the Cladocera order). The effect of both light intensity and photoperiod on Daphnia filtration was studied in laboratory experiments. An increase in the light intensity resulted in two D. magna responses depending on the exposure time of individuals to light. Short time exposures to a decrease in the light intensity of less than one day produced an increase in the D. magna filtration. However, exposures of longer than one day resulted in a decrease in the D. magna filtration along with a decrease in the light intensity. Photoperiod exposures of 8, 12 and 16 h produced greater D. magna filtrations than photoperiods of 0, 4 and 24 h. In this study, regulation of the light intensity and the period of exposure were used in laboratory experiments to establish D. magna development thresholds by latitudinal variation in the photoperiod |
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