Transcript INVERTEBRATES

INVERTEBRATES
Animals that do not have bones
So
They don’t have a skeleton or a
backbone
1.- Classification
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Invertebrates are classified into smaller
groups.
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Sponges
Cnidarians
Echinoderms
Worms
Molluscs
Arthropods
SPONGES
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They are the simplest type of
animal that exits.
They cannot move.They attach
themselves to rocks or the sea
floor.
They are often irregular in shape.
Their bodies have lots of small
holes that allow water to pass in
and out.
They eat microscopic organisms in
the water that they filter through
their body.
CNIDARIANS
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Cnidarians have jelly-fish like
bodies.
They are aquatic animals.
They have very simple bodies with
an opening at one end.This
opening acts like a mouth and an
anus.
They have soft tentacles that can
sting you.
Some, such as coral and sea
anemone, attach to rocks. Others,
such as jellyfish, can move about.
Many cnidarians like jellyfish and
sea anemones have a poisonous
substance in their tentacles to
catch their prey.
Jellyfish
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Sea anemone
white coral
ECHINODERMS
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Echinoderms are symetrical.
Starfish tipically have 5 or
more arms which radiate from
a central point where their
mouth is.
Echinoderms are invertebrates
with hard plates under their
skin.Some like sea urchins
have movable spines on the
outside of their bodies.
They live in the bottom of the
sea.
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Starfish
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Sea urchins
WORMS
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Worms are animals with
long, soft bodies and
moist skin.
They do not have legs.
They move by wriggling.
Most live in the sea or in
fresh water. Some live on
land like earthworms.
Some worms are
parasites. They live in the
intestines of other
animlas and eat their
food.
MOLLUSCS
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Molluscs are classified into 3 groups.
Gastropods.
Bibalves.
Cephalopods.
GASTROPODS
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Gastropods usually have a shell where
they hide in when they sense danger.
They move by sliding on a slimy, mucus
substance that they excrete.
snail
BIVALVES
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Bivalves have one shell divided into 2 moving parts
called valves, which they close when they sense danger.
They usually stay in one place. They eat small organisms
that are in the water.
mussel
clams
oyster
CEPHALOPODS
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Cephalopods have no protective external covering but
some have a shell hidden under their skin.
All cephalopods are marine animals.
They have eight or ten tenctalces that help them to
swim and catch teir prey.
octopous
squid
cuttlefish
ARTHROPODS
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Arthropods have an external skelenton
called exoskeleton which supports and
protects the body.
Classification:
Crustaceans
Arachnids
Myriapods
Insects.
CRUSTACEANS
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Most of them live in the sea.
They usually have 10 legs
The exoskeleton is very hard.
lobster
crab
prawns
ARACHNIDS
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Arachnids ar terrestrial and carnivorous.
Arachnids have 8 legs.
spider
scorpion
MYRIAPODS
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Myriapods have many legs in their bodies.
centipedes
millipedes
INSECTS
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Insects have 6 legs.
butterfly
Many insects have wings.
Their body is divided into 3 parts:head, thorax and
abdomen.
fly
mosquito
bee
grasshopper
wasp