SHELTERING BEHAVIOUR OF SPINYCHEEK CRAYFISH (ORCONECTES LIMOSUS) IN THE PRESENCE OF AN ARTIFICIAL MAGNETIC FIELD

The potential of artificial hideouts, outfitted with magnets or their imitations (control), to attract spinycheek crayfish Orconectes limosus was studied. The experiments were carried out within 1999-2002 in an 80-hectar natural lake. There were three parallel setups, with three experimental treatments (hideouts) each. The presently acquired results suggest explicitly that the magnetic field generated at the entrance to the hideouts (made of ceramic pipes), affects the movement direction of crayfish. This was evident from statistically significant differences between the numbers of crayfish attracted to the pipes equipped with magnets and to the control ones.