PowerPoint about molluscs, their anatomy, ralation with humans and some curiosities.

2. INDEX
-How are molluscs?
-Anatomy of a snail.
-Types of molluscs
-Relation with
humans.
-Curiosities.

3. Molluscs are invertabrate animals, so they dont have a
bony skeleton. They are heterothrophic multucellular
organisms that have eukaryotic cells.
Most molluscs are aquatic, but some of them live in
land.
All of them have:
- A visceral mass, that contains all internal organs.
-An external layer that surrounds the internal organs
inside the visceral mass.
-An internal ot external shell. Some molluscs, like the
octopus don´t have a shell.
-A complete digestive system, which includes the
radula in all individualds except in bivalves.
-They reproduce sexually.

4. This is the anatomy of a snail, that is part of
gastropods. It has a foot use for moving, the
lung, anus, heart, mouth (with a radula use for
biting and chewing) , eyes, tentacles and anus.

5. Types of
molluscs
There are three
types of
molluscs:
-Bivalves
-Gastropods
-Cephalopods
Gastropods and
cephalopods
have foot,
separed head
and a radula.
Bivalves is the
only group that
don t have
them.

6. Types of molluscs
Bivalves have no
separed head from
their bodies. They
don´t have a radula,
like other molluscs,
and don´t move
because they don´t
have foot. They
usually live in water.
They have gills to
respire.
Gastropods hava a
muscular foot, that
they use for
moving. They have
a complete
digestive system
and they are
herbivores. They
have an external
shell.
Cephalopods live in
water and they
have tentacles.
They use their
tentacles to cath
their pray, because
they are carnivores.
Not all of them
have a shell.

7. Some of them can be pets, like the famous ``Pulpo
Poll´´. They have also beneficies in pharmaceuticas
industries, because some of the substances they
segregate can be used to make cream or medicines.
For example, the snail secretion is used to make cream
and the squid ink, was used to make pen´s ink.
And some people like me, considerate molluscs as a
delicious dish.

8. Some molluscs are completelly simetric on
both sides, for exaple the snails. There are
100.000 different types of molluscs, and the
80% are gastropods.
The gigant squid is the biggest mollusc in
the word.
Another curious date is that are 35.000
extint species in thw word, because thay
had soported radical changes.

9. Bibliography
www.moluscos/wikipedia.
com
www.bivalves/wikipedia.c
om
www.10curiosidadessobr
emoluscos.com