Effect of some environmental factors (physical and chemical) on hatching time of Daphnia magna resting eggs

Effect of some environmental factors (physical and chemical) on hatching time of Daphnia magna resting eggs

Authors

  • Sara Haghparast Agriculture Sciences and Natural Resources University of Gorgan, Gorgan, Iran, Iran, Islamic Republic of
  • Ali Shabani Agriculture Sciences and Natural Resources University of Gorgan, Gorgan, Iran, Iran, Islamic Republic of
  • Bahareh Shabanpour Agriculture Sciences and Natural Resources University of Gorgan, Gorgan, Iran, Iran, Islamic Republic of
  • Seyed Abbas Hosseini Agriculture Sciences and Natural Resources University of Gorgan, Gorgan, Iran, Iran, Islamic Republic of

Abstract

The aim of this study was to investigate the mean time of hatching of D. magna resting eggs under some abiotic factors. To do so, resting eggs were collected from different parts of live food ponds in Sad Voshmgir Cultivation and Breeding Centre of Gorgan, and after isolation, the eggs were kept in dry and wet conditions at ٤°C for ٢ months in darkness. Following the pre-incubation period, the two aforesaid groups were subdivided into ٢ smaller parts and each was floated in ١% NaOCL and distilled water for ٥ min. AdaM medium was used to determine the effect of photoperiod levels (continuous illumination, ١٢h light day-١) and temperature levels (٢٠ºC, ٢٥ºC and ٣٠ºC) on the hatching time of resting eggs and the incubation period last for ١٥ days. On the obtained results, the incubation of wet eggs of this species and their subsequent exposure to continuous illumination at ٢٠ºC and ٢٥ºC had a significant shortening effect on the mean time to hatch (P<٠٫٠٥).

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Published

2009-11-13

Issue

Vol. 1 No. 4 (2009)

Section

Articles

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