Skip to main content

THE ELECTRIC FISH

 The idea of a fish being able to generate electricity strong enough to light lamp bulbs or even to run a small electric motor is almost unbelievable, but several kinds of fish are able to do this. Even more strangely, this curious power has been acquired in different ways by fish belonging to very different families. The best known are the electric rays, or torpedoes, of which several kinds live in warm seas. They possess on each side of the head, behind the eyes, an organ consisting of small hexagonal shaped cells rather like a honey comb. The cells are filled with a jelly like substance, and contains a series of flat electric plates.
   The fish gives an even more powerful shock. The system is different from that of the torpedo in that the electric plates run longitudinally and are supplied with nerves from the spinal cord. Consequently, the current passes along the fish from head to tail. The electric organs of these fish are really altered muscles and like all muscles, are to tire, so they are not able to produce electricity for very long.
    The electric catfish has a different system again by which current passes over the whole body from the tail to the head. The shock given by this arrangement is not so strong as the other two, but less unpleasant. The electric catfish is a slow, lazy fish, fond of gloomy places and grows about one metre long, it is eaten by the Arabs in some as areas.
    The power of producing electricity may serve these fish both for defense and attack. If a large enemy attacks, the shock will drive it away, but it appears that the catfish and the electric use their current most often against smaller fish, stunning them so that they can easily be overpowered.

Comments

Popular posts from this blog

Natural soil

 Natural soils are influenced by rainfall and temperature,heavy rain causes the soil to become leached. High temperatures increase the rate of decomposition of organic matter in the soil, thereby lowering its humus content. Thus, climatic conditions tend to produce poor soils in the tropics and rich soils in the temperate regions. Besides climate and vegetation, the parent rock material also contributes to the quality of the soil. For example volcanic rocks tend to produce fertile soils.    Laterite, a red soil which is a product of leaching, is commonly found in the tropics. It is composed mainly of iron and aluminium compounds,and poor in humus and essential plant nutrients, such as phosphorus, nitrogen and potassium. The black and brown soil of the temperate grasslands are the world's richest soils, with a high mineral and humus content. The light coloured desert soils tend to be very rich in minerals but have a low humus content.    Mainly the soils ar...

What do women really want?

What men want is thought to be understood quite well. In general, their sexual desire is orderly, consistent, and narrowly directed. A heterosexual man is heterosexual. If you show him heterosexual sex, his sexual physiology and subjective, reported desire rise in tandem. Homosexual sex will leave him cold both physically and emotionally. For men, there is an excellent match between physiological arousal (as measured by penile tumescence) and level of reported desire. Viagra’s success demonstrates the simplicity of the male mechanism. Viagra does not target desire, but works by increasing genital blood flow, allowing erection. This, apparently, is all that is needed in many cases. As the penis rises, desire is already waiting.       For women, the story is different. The female body, studies show , likes everything, or at least responds to everything (or does not know what it likes, some cynics will say). Female physiological arousal (as measured by vaginal lu...

What the Bible says about marriage and divorce

Matthew 5:31-32  “It has been said, ‘Anyone who divorces his wife must give her a certificate of divorce, but  I tell you that anyone who divorces his wife, except for sexual immorality, makes her the victim of adultery, and anyone who marries a divorced woman commits adultery. Mark 10:2-12 Some Pharisees came and tested him by asking, “Is it lawful for a man to divorce his wife?” 3 “What did Moses command you?” he replied. 4 They said, “Moses permitted a man to write a certificate of divorce and send her away"  “It was because your hearts were hard that Moses wrote you this law,” Jesus replied. 6 “But at the beginning of creation God ‘made them male and female. 7 ‘For this reason a man will leave his father and mother and be united to his wife, 8 and the two will become one flesh. So they are no longer two, but one flesh. 9 Therefore what God has joined together, let no one separate"  When they were in the house again, the disciples asked Jesus about this. ...