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Bioelectromagnetism

3.6.1 Electroreception

Electroreception is common in aquatic animals. It has been found in a number of vertebrate species

including the fsh, amphibians, and platypus (Kalmijn, 1971; Hurd et al., 1984; Gregory et al., 1987). In

aquatic animals living in electrically conductive environment such as seawater, electroreception relies

on direct transmission of stimulus from the water (conductive medium) to the nervous system though

Lorenzini (conductive receptor channels). Ampullary electroreception needs the presence of an electri­

cally conductive medium.

In the past, electroreception in an aerial environment had been hypothesized. Recently, for terrestrial

animals in air, Sutton et al. concluded that sensory hairs are a site of electroreception in the bumblebee

(2016). In fair weather, a static electric feld is the order of amplitude of 0.1–0.2 kV/m as a consequence of

the global atmospheric electric circuit. Te electric feld is a very important key factor for the electrobiol­

ogy. Te relevance of static electric felds for electrobiology has been considered (Reiter, 1992). Human

and terrestrial animals have no use of electroreception due to high electrical resistive medium of air

(insulator) environment. Tey can detect electric discharge through sensory and motor nerve fbers

stimulation from direct or indirect contact with conducting objects.

In animals living in terrestrial environment, the detection of electric feld must operate diferently

using diferent sensory mechanisms (Clarke et al., 2017). Recent studies provided behavioral evidence in

bees for electroreception. Te electroreception of insects such as honey bees can detect very weak static

electric feld as the electrobiology will be introduced. Te relevance of static atmospheric electric feld for

biology has been considered (König, 1979, König et al., 1981). Te research focused on the relationship

between insect pollinators and plants (Clarke et al., 2013). Bumblebees (Bombus terrestris), a solitary

species and honey bees (Apis mellifera), and social hive species have the detection of weak static electric

felds using diferent sensory mechanisms (Clarke et al., 2013; Greggers et al., 2013). In Bumblebees, the

detection of static electric feld is through mechanosensory hairs, which are mechanically defected by

an applied electric stimulation (Sutton et al., 2016). Flowers generate weak electric feld and bumblebees

can sense those electric felds using the tiny hairs on their fuzzy bodies. Bumblebees beat its wing up to

200 times per second through the air. Bumblebees can sense the presence of weak electric feld surround­

ing fowers and discriminate between static electric felds with diferent radial geometries (Clarke et al.,

2013). Bumblebees detect electric felds around plants and learn to use them to decide whether or not to

visit fowers. Te sensory basis for electroreception in honey bees was hypothesized to be the antennae,

electromechanically coupled to the surrounding electric feld in virtue of bees being electrically charged

(Greggers et al., 2013). Honey bee uses their antennae. Te antennae oscillate under static electric feld.

Tis stimulation can elicit activity in the antennal nerve. Honey bees with removed or fxed antennae are

less able to associate food reward with static electric feld stimulation (Greggers et al., 2013).

It was shown that spiders can use electric feld in fair weather to balloon upwards (Morley and Robert,

2018). Spiders can detect static electric feld in natural atmospheric electricity. Te ballooning behavior

of spiders is triggered by these static electric felds. In the experiment, a static electric feld was generated

with electrodes that simulated the atmospheric electric environment, and spiders (Linyphild, Engone)

were placed in the feld to observe their behavior. When the electric feld was turned on, the spider’s

abdomen stood up, and it exhibited ballooning, a preemptive behavior in which the spider blew out its

silk threads. On the other hand, when the electric feld was turned of, the spider moved downward.

Since spiders have trichobothria, which are mechanical receptors, it is possible that these act as recep­

tors for sensing electric felds. Te authors found that hairs respond to a small amount of air fow, or

stimulation from an electric feld. Te spider, which does not have wings, uses silk threads blown out of

its body to perform ballooning using atmospheric electricity. It was concluded that atmospheric elec­

tricity could provide forces sufcient for dispersal by ballooning in spiders and hair-shaped sensors are

putative electroreceptors (Morley and Robert, 2018).

In 1917, Parker and van Heusen published historically well-known paper on the nibbling response of

the catfsh (Amiurus nebulosus) to metallic and non-metallic rods (1917). Tey found that a blindfolded