Overview of molluscs - Phylum Mollusca Snails, slugs, clams,
mussels, squids and octopuses are all very different-looking
animals. However, they are all molluscs. Molluscs live almost
everywhere - on the rocky shore, in freshwater habitats and in
your garden. Generally molluscs have: - an unsegmented, soft
body - a muscular foot or tentacles - a mantle that can secrete
a shell Most, but not all, molluscs have: - an internal or
external shell - a radula (tongue with teeth) Molluscs are one
of the largest animal groups with about 200,000 species
worldwide. The number of species in Australia is about 15,000
with more than 2,000 known from Sydney. Sydney has an amazing
diversity of molluscs, from the Little Blue Periwinkle the size
of your little fingernail to the Giant Cuttlefish over 1 m long.
Despite the many differences in external appearance, their
internal structure is very similar. Mollusca means 'soft-bodied'
and, although some have developed a tough shell, they are all
soft on the inside. Molluscs are fu