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The body shape of almost all
piranhas is high-backed , more or less stocky , and very narrow.
The piranha's shape indicates that they live in slow-flowing and
stagnant waters . The head is large, with a steep profile. The keel
formed by enlarged scales and more or less extending along the midline
of the belly is toothed like a saw. It is to this "SAW" that the
whole piranha family, Serrasalmidae (Saw Salmon), owes its name. |
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The largest piranha grows to
be about 2 feet long. Most other piranhas are a little over or a
little under 1 foot long. There are many species of smaller piranhas
whose average size is between 8 and 12 inches. |
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The Natural
Range Of The Piranha includes:
1.The Orinoco Range
2.The Guyana Range
3.The Amazon Range
4.The Rio Sao Francisco Range
5.The Rio Paraguay and Rio Parana Range
Piranhas, in the wild, can be
found only in South America. They are freshwater tropical
fish. Piranhas live in the so-called white water rivers in
the wild. Piranhas never live in mountain streams or lakes. |
Distribution Map |
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The round scales
of the piranhas are small and set in the skin like the tiles on
a roof, arranged in horizontal and vertical rows. They form an effective
barrier against infection and foreign bodies. Above the scales lies
a layer of skin that secretes mucus, which gives the fish its slimy
texture. Attacks and scratches constantly result in the loss of
scales. This loss is harmless since the scale regenerate quickly.
Piranhas do not actually produce color. Rather, the color is created
by many pigment-containing cells - the chromatophores - in the skin
in which the scales are embedded. If numerous cells with red pigment
lie close together, the area concerned will look red. |
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Every piranha has both paired
and unpaired fins. Paired fins include the pectoral fins, which
are inserted behind the gills, and the small ventral fins, attached
on the abdomen, behind the pectorals. The unpaired (vertical) fins
consist of the long-lobed anal fin that lies between the anus and
the caudal peduncle; the caudal (or tail) fin, which has only a
shallow notch; the dorsal fin; and the well-developed adipose fin
behind it. |
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Most people outside
South America first learned about piranhas in 1914 from Theodore
Roosevelt, a former president of the United States. When he came
back from his Amazon travels, he told terrifying stories about the
fish. One story he told was about a soldier in Brazil who fell off
his horse into the river and was eaten so completely that only his
bones were left! It is probably true that the travelers found the
soldier's skeleton, but it is most likely that he drowned and was
later eaten by the many aquatic animals, including piranhas, that
eat dead flesh. |
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Piranha teeth
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The most famous part of a piranha's
body is its teeth. Their teeth are sharped like triangles.
The lower jaw of a piranha sticks out farther than its upper
jaw. This makes the piranha's teeth fit together like a trap.
When a piranha bites something, it easily tears it into tiny
pieces. The lower jaw is big and immensely powerful. Hidden
behind the lips there is alarge, extremely pointed and razorblade-sharp
set of teeth. Because of their razor powerful teeth they cause
serious injuries or death even to large warm-blooded animals. |
Piranha profile |
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Piranhas eat
small fish, shrimp, tiny crustaceans, insects, the flesh of dead
animals, and even fruit, seeds, and pieces of plants. Some piranhas
prefer a diet of fins or scales from other fish. A few piranhas
eat mostly vegetables. |
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When piranhas
eat, they use their teeth only to cut and bite, they never chew
their food. Instead of chewing, they swallow their food whole. By
doing this, they can eat very, very quickly. With so many piranhas
eating during a feeding frenzy, the food disappears quickly. The
faster a piranha can eat, the more food it gets! |
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Thanks to the
position and shape of the eyes, piranhas, like most fishes, have
a very wide field of view. To a limited extent they are able to
percieve movements that go on behind them. This means that the fish
become aware of possible danger at an early stage and thus have
an increased chance of escaping. |
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Little is known
about when piranhas become sexually mature. Breeding occurs during
one of two spawns - one before the rainy season in April/May and
possibly a second one in late summer. Prior to spawning the general
aggressiveness of the piranhas increases considerably, and members
of the same species are bitten more frequently. |
