Page 120 - The World of Animals

A fish does not have eyelids as do human beings. It looks at the
world through a transparent curtain covering its eyes. This curtain

resembles a diver's eyeglass. Since they usually need to see objects very

close to them, fish's eyes have been created to meet this need. The
spherical and hard structure of their eyes are adjusted to see objects
close to them. When they want to look at an object at a distance, the

lens system is drawn backward by means of a specific muscle
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mechanism in the eye.
Beside its five basic senses of sight, smell, hearing, touching and
taste, the fish also perceives the outside world through its "lateral"

lines. Sensitive nerves that lie along these lines perceive the size and

direction of objects the fish passes by. In this way blind cave fish can
move very easily in the dark. This system is a kind of underwater radar
or "sonar" system.

Furthermore, many fish species have a long and slender balloon-like

air-filled sac in the abdominal cavity. They maintain their balance in
the water with the help of this sac.
Fish of various kinds created by the will of Allah amaze people with

their beautiful colours and movements. You can hardly find such vivid

colours as those seen in many fish in any other animal.