The influence of the low-frequency direct and variable fields common action on the daphnia heart rate has been investigated. During investigation the single daphnia from aquarium culture was placed into the camera which confines the daphnia movements. Video image of the daphnia heart rate was analyzed using special developed program. The amplitude of the variable magnetic field inside of the camera near it’s bottom was 25 mTl, the maximum induction of direct magnetic field orthogonal to variable one was 1.2 mTl. Time of fields common action was 1 hour. Daphnia heart rate variation was recorded for 0 individuals.
The measurement of daphnia heart rate was carried out before and after magnetic fields influence. The measurements of daphnia heart rate shift depending on the frequency of influence of variable magnetic field at inductions of 1.2 mTl, 0.8 mTl, 0.6 mTl and in the absence of magnetic field. It has been determined that when direct field induction decreases from 1.2 mTl to 0.6 mTl. The variation of daphnia heart rate increases approximating to the values obtained in the absence of direct magnetic field. Also the dependence of the daphnia heart rate shift on the induction variable magnetic field at the frequency of 6 Hz with direct magnetic field induction of 1.2 mTl has been measured. The results of measurements show that the presence of magnetic field direct component leads to evident decrease of daphnia heart rate shift. At the same time, the frequency dependence of daphnia rate shift on the increase of direct magnetic field induction become less and less expressive. It is noted that observed regularities can be used for explanation of the magnetic fields influence on the aqua medium and bioobjects.