Transcript mollusc - WordPress.com

Today i´m going to explain a presentation
about mollusks









Information
Bivalves
How do they eat
Gastropods
Cephalopods
Mollusks and humans beings
A Pearl
Questions
Videos
Any of some 75,000 species of soft-bodied invertebrate
animals (phylum Mollusca), many of which are wholly or
partly enclosed in a calcium carbonate shell secreted by
the mantle, a soft covering formed from the body wall.

Bivalves (Bivalvia) are a group of molluscs that
include clams, scallops, oysters, mussels,
razor shells, cockles, venus shells, borers,
trough shells and many others (some of
which have yet to be identified
Bivalves are filter feeders,this means that they stract nutrients from the
water.
Mollusks have a rough tongue called radula.it’s gotmany tiny teeth on it’s
surface. mollusks use their radula to scrape food and break it into smaller
pieces.



Many gastropods,like snails,have got a spiral shell.other gastropods,like
slugs,haven’t got a shell
Gastropods have got a head and body.they’ve also got four tentacles.
Most gastropods are hervivores



Cephalopods have got a head with a mouth and well-developed eyes.
They’ve also got long arms to catch their food.Some cephalopods,like
squid have got tentacles too.
Most cephalopods are carnivores



We use mollusks for a number of purposes.
We can eat somo types of mollusks,such us
mussels,clams,oysters,cockles,squid,and octopuses
We can also use the shells and pearls of oysters to make jewellery and
beautiful objects

Sometimes a small grain of sand is between the oyster’s shell and the
mantle ,the oyster produces a hard shiny substance called nacre to
protect itself.The sand is slowly covered with many layers of nacre that
eventualy form a pearl.for this reason ,nacre is called ´mother of pearl´





1.How do bivalves eat?
2.what is the name of the substance of the oyster?
3.how do we call snail’s tongue?
4.bivalves have a shell?
5.have gastropods a shell?





1.they filter the water
2. nacre
3.radula
4.no they haven’t
5.yes they have