For example, the anglerfish carries
its own “fishing rod” to catch other fish.
An extended part of the back fin has
wormlike pieces of flesh at the tip,
Yellowspot emperor fish swim in a group
called a school.
BRITANNICA STUDENT ENCYCLOPEDIA Fish 27
which are the “bait.” Anglerfish of the
deep sea have bait that lights up to
attract victims.
Behavior
Fish swim mainly by sideways movements
of the body and tail. They use
their fins for balancing, steering, and
braking. To move quickly from a resting
position, some fish shoot a stream of
water out of the gills, which causes them
to lunge forward. The fastest swimmers,
such as the tuna, can travel 30 miles (48
kilometers) per hour.
Many fish have adaptations to help protect
them from enemies. For example,
some fish have spots near their tail that
look like eyes. When an enemy strikes at
what it thinks is the head, the fish can
escape quickly. Other fish can change
color and pattern to match their surroundings
and hide themselves from
enemies.
Most fish eat other, smaller fish. The
smallest fish eat tiny water plants and
animals called plankton. Plankton also
includes fish eggs. It drifts with the currents
in large numbers.
Reproduction
All fish hatch from eggs. Usually the
females release eggs and the males release
sperm into the water. When the eggs
and sperm meet, the eggs are fertilized.
Many of the eggs, and the young that
hatch from them, are eaten by other
fish. To increase the chance that some
young will survive, some females release
as many as a million eggs.
Some kinds of fish try to protect their
eggs. The female might dig a nest in the
sandy bottom and lay her eggs there.
The female sea horse lays her eggs in a
pouch on the belly of the male, where
they stay until they hatch. Some male
catfish carry the eggs in their mouth.
Sometimes the eggs are fertilized in the
female’s body and hatch there. Then the
young are born live from the female.
Fish born this way have a better chance
A diver swims with a whale shark, the largest
of all living fish. The whale shark is
harmless to humans.
An anemone fish shelters in the tentacles of
a poisonous sea anemone. The poison does
not hurt the fish.
28 Fish BRITANNICA STUDENT ENCYCLOPEDIA
of survival. Guppies and some sharks
have live births.
Fish and Humans
Fish are valuable to people in a number
of ways. In many places fish are a major
source of food. Also, people keep fish as
pets in home aquariums. Some people
enjoy fishing as a sport. However, too
much fishing by commercial boats has
greatly reduced the number of certain
fish. Fish are also harmed by pollution.
#More to explore
Adaptation • Catfish • Eel • Plankton
• Protective Coloration • Sea Horse
• Shark • Tuna
Flag
A flag is a piece of cloth or other material
that carries a design. A flag is often
attached on one side to a pole or a stick,
called a staff. Every country and state
has its own flag. Some cities, groups,
and people have flags as well.
A flag is a powerful symbol. People
show a flag the same respect that they
show to the country or group it
represents. Many governments have
laws about flag use.
Flags of Countries
Betsy Ross may have sewn the first U.S.
flag in 1776. Since then the U.S. flag
has changed many times. The flag now
in use has 50 stars that stand for the 50
states. Its 13 stripes stand for the 13
original states. However, no state has its
own particular star or stripe.
The flags of other countries also have
meanings. Most flags of Islamic countries
use the crescent moon, the color
green, or both. These are symbols of
The earliest U.S. flags had the 13 stars arranged in different patterns. A new star was
added for each new state that joined the country. Since 1960 U.S. flags always have the
same pattern of 50 stars.
BRITANNICA STUDENT ENCYCLOPEDIA Flag 29
Islam. Many of the traditionally Christian
countries of Europe have a cross
(the symbol of Christianity) on their
flags.
Special Flags
Flags may serve special purposes. A flag
honors the dead when it flies halfway
down the pole. A yellow flag is a
warning of contagious, or catching,
disease. A white flag in a battle is a call
to stop the fighting. An upside-down
flag on a ship is a call for help. Some
flags have designs that stand for
numbers or letters. People use sets of
these flags to send messages over a
distance.
Flag History
The people of ancient China and India
used some of the first flags. These early
flags often flew over armies in battles. If
a flag fell, it meant that the commander
had been captured or killed.
Ancient Roman soldiers on horseback
carried a square piece of fringed cloth at
the end of a spear. Later, European
The modern flag of the United Kingdom combines symbols of England, Scotland, and Ireland.
Most flags are rectangular. But some flags are squares, triangles, or other unusual shapes.
The shape of the flag of the U.S. state of Ohio is called swallow-tailed.
30 Flag BRITANNICA STUDENT ENCYCLOPEDIA
countries used flags to represent themselves.
By the end of the Middle Ages in
about 1500, cities and guilds (groups of
skilled workers) also had flags.
#More to explore
Ross, Betsy
Flamingo
