The response of the crab Paralithodes Camtschaticus (Tilesius, 1815) to geomagnetic storms

Abstract

There are a number of environmental factors for whose perception Nature has not provided living organisms with special receptors. The most important one is the geomagnetic field. If animals had magne� toreceptors, they could use them as a compass to ori� ent in Earth’s magnetic field. Therefore, many researchers have long been trying to discover the abil� ity to perceive the geomagnetic field in different ani� mal groups and in humans with the use of a variety of techniques [5, 8]. However, these studies are notable for the lack of reasonable assumptions on the mecha� nisms of action of magnetic fields on animalsThe dis� covery of electroreception in some fish species gave the opportunity to prove, with the help of rigorous meth� ods of sensory physiology, the ability of animals to per� ceive Earth’s electric and magnetic fields [4]. How� ever, electroreceptors were found in a small group of fish. The finding of biogenic magnetite in many ani� mals allowed a new insight into the problem of magne� toreception [3]. For this reason, a hypothesis on the possible use of biogenic magnetite by animals for geo� magnetic orientation is attractive among biologists [1, 2]. The finding of the ability of certain sensory structures to perceive magnetic fields is also important for sen� sory physiology, because this is evidence for a new type of receptors (magnetoreceptors) that may help to explain orientation and migration behaviors. How� ever, these sensory formations have not been found in animals thus far. Invertebrates, including crabs, lack electrorecep� tors, although, in the course of evolution and vital activity, they are exposed to variations in Earth’s mag� netic field. Therefore, our study was aimed at evaluat� ing the possibility of perception of the geomagnetic field and its variations by invertebrates as exemplified by crabs. We used a special experimental setup to study the locomotor activity of crabs under the action of the geomagnetic field. The setup contained a kinematic block, a transducer of direct current to modulated