Piranhas
Scientists
in
the
UK
have
announced
that
the
piranha
fish's
reputation
as
a
____________________
killer
may
well
not
be
deserved
.
The
fish
,
which
is
found
in
the
Amazon
in
Brazil
,
have
been
portrayed
as
deadly
____________________
that
work
in
shoals
to
overwhelm
their
____________________
and
strip
it
of
its
flesh
in
seconds
.
However
,
____________________
from
St
Andrews
University
say
that
piranhas
are
____________________
that
mainly
eat
fish
,
plants
and
insects
.
They
form
big
groups
not
to
hunt
but
to
____________________
themselvers
against
other
predators
,
according
to
the
team
.
"
Previously
it
was
thought
piranhas
shoaled
as
it
enabled
them
to
form
a
cooperative
hunting
group
,
"
said
Professor
Anne
Magurran
.
"
However
,
we
have
found
that
it
is
____________________
a
____________________
behaviour
.
"
Piranhas
can
be
____________________
by
animals
such
as
dolphins
,
caimans
and
large
fish
,
so
forming
a
shoal
is
a
good
way
of
____________________
being
killed
.
Piranhas
of
____________________
age
stay
in
the
middle
of
the
group
for
____________________
and
the
size
of
the
shoal
differs
according
to
the
level
of
risk
.
When
the
water
level
is
high
,
the
fish
form
small
groups
as
there
is
space
to
escape
,
but
when
the
water
level
drops
,
they
form
large
groups
as
____________________
against
predators
.
