Frontiers in Marine Science (Nov 2015)
Delayed consequences of extremely low frequency magnetic fields and the influence of adverse environmental conditions on roach Rutilus rutilus L. embryos
Abstract
It is widely known that animals are most sensitive to the influence of different environmental stressors, including magnetic fields, during the embryonic period. Our study presents data collected over a six-year period on the effects of extremely low frequency magnetic fields (MFs) (1.4-1.6 µT, 500 Hz and 1.4-1.6 µT, 72.5 Hz) and MFs in combination with other environmental stressors (elevated temperature, 0.01 mg/L water solution of trichlorfon, 0.01 mg/L water solution of copper sulphate penta-hydrate) on roach embryos. The effects of these stressors were studied during different stages of early development. The fish developed in ponds for four months after exposure to MFs. The weight, standard length and morphological characteristics of underyearlings which developed from the exposed embryos were recorded. An increase in embryo mortality and a decrease in size-weight indices in underyearlings were noted after fish had been exposed to a combination of magnetic fields and different adverse environmental factors. In addition, exposure to magnetic fields led to changes in the total number of vertebrae and in the number of seismosensory system openings in the mandibular bones of underyearlings. Magnetic fields of different frequency caused both increases (500 Hz) and decreases (72.5 Hz) in underyearlings' morphological diversity. The stressors used did not increase the fluctuating asymmetry of bilateral morphological characters. The possible microevolutionary effects of exposure to magnetic fields alone and in combination with other adverse environmental factors upon natural fish populations are discussed.
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