Molluscs Flashcards
example of molluscs species
clams, oyster, squids, octopus, snail
where do they live?
marine, fresh water, terrestrial
are they soft or hard
all soft bodied some secrete a hard shell
what are the three main parts of the molluscs
- muscular foot
- visceral mass
- mantle
What is involved in the muscular foot?
involved in movement and senses
what is the visceral mass?
digestive, aculatory, respiratory, reproductive and sensory organs
what does the mantle do
excretes hard shell
what are the three main groups?
- gastropods
- bivalve
- cephalopods
give example of the species in gastropods
snails, limpets, whelks, conch, sea hares, periwinkles, sea slugs
what makes gastropods different from other molluscs
they are the only molluscs to invade land
what does the outer and inner layer of gastropods shells consist of
outer layer consists of conchiolin and inner consists of calcium carbonate
what is the benefit of the pearl layer on the inside of the shell
pearl from inside shell as a defence against potentially threatening irritant such as a parasite
what are the three classes of gastropods
Prosobranchia- periwinkles and limpets
Opisthobranchia- sea hares and sea slugs
Pulmonata- land and fresh water snails
what animals belong to the bivalve group
mussels, clams , scallops, oysters,
what type of feeders are bivalves
suspension feeders
do bivalves have a brain
no
have do bivalves open and move
held by a hinge ligament adductor to open
valves held by teeth in hinge
what does cilia in the stomach of bivalves do
cause rotation of the contents
what happens to waste material in bivalves
pushed through the rectum via anal pore
what is the benefit of the bivalves shell
defence and support internal organs
how does filter feeding work in bivalves
cilia on the gills capture food and they are also used for gas exchange
what are the species that belong to the cephalopods group
cuttle fish, squids, octopus
what type of feeders are cephalopods
predators
do cephalopods have a brain
they have a brain which the cranium protects and it has separate regions that have different functions
what are the inc sacs in cephalopods for
released when the animal is alarmed
cephalopods have chromatophores for what?
they are present so effect of camouflage is enhanced by reflector cells
