Electro-Reception

1. Electro-Reception Calvin Laverick

2. Why the PowerPoint Calvin? • First seen in S1 E1 of “Inside the animal mind”. • http://www.bbc.co.uk/programmes/b03thwhf

3. Definition • Electro reception is the biological ability to perceive natural electrical stimuli.

4. What animals can use it? • It has been observed almost exclusively in aquatic or amphibious animals. • These include sharks. • It is thought that this is because water is a much better conductor of electricity than air. • A list of known animals can be found here.

5. It was thought that electroreception is only found in vertebrates. • However, new research shows that bees can detect the presence and pattern or a static charge on flowers. • The organs needed for electroreception is thought to derive from the Mechanosensory system.

6. In most groups of animals electroreception is passive. • This means not under direct mental control. • This is thought to be because it is used in predation. • Predation meaning predatory activities. • An exception to this rule can be found here.

7. How is it used? • There are 3 main types of use for electroreception: • Electrolocation • Active and passive. • Electrocommunication • Sensory mechanism: • Hence it’s allowance into the Mechanosensory system.

8. Active Electrolocation • This is when the animal generates electrical fields around itself: • This is by using electroreceptor organs. • It then detects distortions. • A phenomenon known as Jamming Avoidance response can be found here.

9. Passive Electrolocation • In this process the animal simply detect weak bioelectric fields given off by other animals and uses them to locate the animal. • This bioelectric field is given off by all animals due to the activity of their nerves and muscles. • A second source of this field can be found due to Osmoregulation in ion pumps in the gill membrane.

10. Electrocommunication • Weakly electric fish can communicate by modulating the electrical waveform they generate. • This is often used for mate attraction and territorial displays.

11. Sensory Mechanisms • A loose plug of epithelial cells which capacitively couples the sensory receptor cells to the external environment. • This means that they can detect electric communication signals of other fish.

12. Primary Example • Sharks and rays have organs known as the ampullae of Lorenzini. • These consist of electroreceptor cells connected to the seawater by pores on their snouts and other zones of the head. • It is thought that this is used by sharks to detect the worlds magnetic field and navigate the earth.

13. Other examples • Electric eel: • Used for attack, navigation and prey detection. • Monotremes: • These include the platypus. • Bees: • They detect a positive static charge while flying through the air.

14. Effects On Wildlife • An unusual effect is that electromagnetic fields generated by pylons and masts have adverse effects on wildlife.

15. Sources • http://en.wikipedia.org/wiki/Electroreception • http://en.wikipedia.org/wiki/Mechanosensory • http://en.wikipedia.org/wiki/Jamming_avoidance_response