PHYLUM MOLLUSCA (SOFT BODIED ANIMALS): GENERAL CHARACTERS
Mollusca is the second largest phylum.
- Grades of organization:
- Organ system.
- Bilateral symmetry.
- Few are terrestrial.
- Gills in aq. forms and pulmonary sac in terrestrial forms.
- Open type.
- Development is direct or indirect.
- Body has head, visceral hump & muscular foot.
- Head has sensory tentacles.
- Calcareous shell.
- Mantle: The membrane which covers visceral mass.
- Space between the hump and mantle is called mantle cavity. It contains feather-like gills for respiration & excretion.
- Radula: File-like rasping organ present in the mouth. It is used for feeding.
- Pila (Apple Snail), Pinctada (Pearl Oyster), Sepia (Cuttlefish), Loligo (Squid), Octopus (Devil fish), Aplysia (Sea Hare), Dentalium (Tusk shell), Chaetopleura (Chiton).
👇 Select Your Topic Here 👇
- Topic 1: Basis of Classification
- Topic 2: Porifera
- Topic 3: Cnidaria
- Topic 4: Ctenophora
- Topic 5: Platyhelminthes
- Topic 6: Aschelminthes
- Topic 7: Annelida
- Topic 8: Arthropoda
- Topic 9: Mollusca
- Topic 10: Echinodermata
- Topic 11: Hemichordata
- Topic 12: Chordata - up to Sub phylum Vertebrata
- Topic 13: Chordata - Cyclostomata, Pisces
- Topic 14: Chordata - Tetrapoda