NATURE IS FULL OF BLOSSOM AND BEAUTY AND IT ATTRACTS EVERY ONE WHO WANNA DIVE INTO IT, ONE OF THE FLOWERS OF NATURE ARE MOLLUSKS WHICH ARE CALLED THE BEAUTY OF THE OCEANS AND THEY ARE PRESENT IN A LARGE VARIETY. SO, HERE IS SOME CUTE AND INTERESTING INFORMATION ABOUT MOLLUSKS FOR YOU GUYS. ALIKE WILL BE APPRECIATED.

1. PRESENTED BY:
MUHAMMAD SOHAIB
PRESENTED TO:
SIR ASAD ALI

2. CONTENTS
• INTRODUCTION
• BIODIVERSITY
• classes
• famous….
• MORPHOLOGY
• ECOSYSTEM
• ecology
• environment
• habitat
• GEOGRAPHICAL RANGE
• FACTS
• BIBLIOGRAPHY

3. INTRODUCTION

4. BIODIVERSITY

5. CLASSES
• Cephalopoda
• Monoplacophora
• Gastropoda
• Scaphopoda
• Pelecypoda
• Rostroconchia
• Polyplacophora
• Aplacophora
Ultimate Evolutionary Ancestors
Low Abundance
Most Abundant
Abundant

6. FAMOUS….
Also Called “STOMACH-FOOT”
Highly Diversified Class In Phylum
Uni-valve
Can Be Uni-shell Or No-shell
Only Mollusks Found On Land
Simple Nervous System With Small Brain
All Gastropods Have Mouth With Radula
e.g: Snails, Slugs, Abalone, Chitons, Limpets
GASTROPODA

7. FAMOUSCOUNT…
Also Called “HEAD-FEET”
Most Active Mollusks
Most Complex & Recently Evolved
Moves Very Fast Using Their Arms And Tentacles
Most Complex Nervous System
Can Have & Lack Shell
Propel Themselves With Jets Of Water
e.g: Cuttlefish, Squid, Chambered Nautilus
CEPHALOPODA

8. FAMOUSCOUNT…
Also Called “NO-FEET”
Bi-Valve
Most Lazy Mollusks
Stay Stationary
No Such Evolution
Lack True Nervous System
Stay On The Surface Of Bed
Use Mantle Cavity To Feed & Gaseous Exchange
e.g: Clams, Scallop, Mussels, Oyster
PELECYPODA

11. STRUCTURE
FO4UR PARTS
RADULA:
Strap Like Rasping Organ Used To Scrape Up Food With Curved
Teeth. It Contains Mouth , Eyes And Tentacles.
FOOT:
It Allows The Mollusks To Scrape Algae And Other Food Off Of
Rocks And Drill Through The Shell Of Prey Or Catch Fish. It Is
Ventral , Thick And Muscular . Variously Modified For Creeping
And Seizing .

12. STRUCTURECOUNT…
MANTLE:
A Fold Of Tissue That Drapes Over The Visceral Mass And Secretes A
Shell If There Is One Present
• Mantle Cavity:
Water-filled Chamber That Houses The Gills, Anus, And Excretory Pores
VISCERAL MASS:
Visceral Mass- Contains Internal Organs Used For Digestion,
Excretion, And Reproduction

14. SHELL
IT CONSISTS OF TH3REE LAYERS

Outer Layer Made Of
Conchiolin (protein)

Middle Layer Made Of
Calcium Carbonate

Inner Layer Made Of
Calcium Carbonate (Crystalline)

15. TYPESOFSHELLONBASISOFVALVE
FI5VE TYPES
UNI-VALVE:
Which Have Only One Shell At Top & Have All Body Organs e.g: Snails
BI-VALVE:
Which Have Two Shell Joined Together & Lack Some Mollusks Organs e.g: Oyster
PEEUDO-BIVALVED:
Which Are Univalves When Larva And Bivalves When Adult e.g: Rostroconchia
MULTI-VALVED:
Which Have Multi Valves & Are Rare In Nature e.g: Unknown
SPICULES:
Which Have Needles Like Structures Made Of Any Material e.g: Sea Urchin

16. DIGESTIVESYSTEM
The Digestive Tract Is
Complete And Ciliated With A
Mouth, Anus, And Complete
Stomach.
Food Is Taken Up By Cells In
The Lining Of The Stomach
And Passed Into The Blood

17. EXCRETERYSYSTEM
Excretory Functions Are Carried Out By A Pair Of Nephridia
NEPHRIDIA:
Tubular Structures That
Collect Fluids From Coelom
And Exchange Salts With
Body Tissues As Fluids Pass
Along The Tubules.

18. NERVOUSSYSTEM
 Relatively Complex
o Most Complex- Octopus
 2 Pairs Of Main Nerve Cords
o Visceral- Serve The Internal Organs
o Pedal-control The Foot
 Brain Encircles The Esophagus
 Sensory Ability
o Variety Of Organ Systems
o Large, Complex Eyes
 Larges Eyes- Large Squid
(eyes The Size Of Dinner Plates)

19. RESPIRATORYSYSTEM
Respiration Pigment- Hemocyanin
Respiration Is Through Gills, Ctenidia, Located In The Mantle
Cavity

20. CIRCULATORYSYSTEM
 Open Circulatory System.
 The Blood Does Not Circulate Entirely Within Vessels But Is
Collected By The Gills, Pumped Into The Heart, And Released In
Spaces In The Tissue (Hemocoel) and Returns To The Gills, Then
The Heart.
■ HEMOCOEL- "BLOOD CAVITY"

21. REPRODUCTIVESYSTEM
 Sexual
 Can By Simple Or Very Complex
o Varies In Different Classes
 Fertilized Egg Develops Into
A Swimming Form Called A
Trochophore Larva.
 This Then Elongates To Become
A Veliger Larva.

22. LOCOMOTORYSYSTEM
● Varies, But Is Dictated By The Structure Of The Foot
● Herbivorous Forms Are Gliders, Moving On Waves Of Muscular
Contraction.
● Cephalopods Swim Actively By Jet Propulsion In Which Water
Is Rapidly Expelled From The Mantle Cavity.
● Cuttlefish And Sea Hares Rely On Lateral Fins For Locomotion.

24. ECOSYSTEM

25. ECOLOGY

26.  Any Terrestrial Or Aquatic Environment
o Mostly Have Marine Habitat
o Some Live In Terrestrial Habitat [Moist Land]
 Both Shallow And Deep Regions Of The
Ocean, Fresh Water, And Most Land Areas
ENVIRONMENT&HABITAT

27. GEOGRAPHICALRANGE

28. FACTS
 First Organism With Complete Body System.
 Largest Marine Phylum.
 There Are About 85,000 Species Of Mollusks.
 Most Intelligent Phylum Of All Marine Phylum.
 Most Beautiful Of All.
 2nd Largest Animalia Phylum.
 Mollusks Serve As Food For Humans As Well As For Other Animals.
 They Are Used For Pearls And Native American Currencies.
 Some Are Used As Environmental Indicators Because Their Bodies Are Filled
With Water.

29. BIBLIOGRAPHY
 notes
 https://www.slideshare.net/jodie26/molluscs-1396548
 https://www.slideshare.net/agospodarek/mollusks-8083518
 https://www.slideshare.net/loulizerlinfante/mollusks-
31292566
 https://www.slideshare.net/mcdevittapbio/phylum-mollusca-
11870161