Which fish is the slowcoach of the sea?
The living world
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Fish have been around for 400 million
years! They live in seas, rivers, and
lakes. Wherever you find water,
you can bet there are plenty
of fish swimming around.
Fish out of water
Mudskippers are one of the only fish that can
survive out of water. They have special gills
that take oxygen from air or water. They skip
along mudflats using their fins as elbows.
Gills
Like other
animals, fish
need to take in
oxygen in order to live.
But, unlike us, they can
breathe underwater using
their gills. Fish gulp in water and
their gills filter the oxygen out of it.
Fish have fins
that keep them
upright when
they swim.
The tail of a fish sweeps
from side to side to
push the fish forwards.
The gills lie
behind the eyes.
Fish skin, made
up of scales, is
slimy to let them
slip through
water easily.
Types of fish
There are over 24,000
types of fish, which
fall into three groups.
Bony fish:
95% of the fish
in the world are bony fish
with hard skeletons.
Cartilaginous fish:
rays,
skates, and sharks
make up this group.
Jawless fish:
only
hagfish and lampreys
fall into this small group.
The world of fish
Mudskipper
Bony fish have
a skeleton with
a skull, ribs, and
a backbone.
Pyjama
cardinalfish
