this may help you at some how.

1. Subject : Marine Biology
Lectured by : Prof: Chea Leng
Room : Samdach Oum Su
Topic : Biology of Molluscs
Prepared by : Group 2

2. Biology of
Molluscs

3. Content
• Introduction
• Digest
• Nervous System and Behavior
• Reproduction and Life History
• Reference
• Q and A
3

4. Digestion
• Digestion involves Salivary and
digestive glands.
• Other aspect of the digestive system
differ among groups and according to
diet.
4

5. • Chitons and many snail are grazers
Digestion (Con’t)
5

6. Elisha's Ecology of Atlantic Shores H
6

7. • Molluscs have a circulatory system:
o Open circulatory system
• Blood flows out of vessels into open blood
spaces
o Closed circulatory system
• The blood always remains in the vessels and
can be more effectively directed to oxygen
demanding organs such as the brain
Digestion (Con’t)
7

8. sharon-taxonomy2009-p3 - Mollusca
8

9. Nervous System and Behaviour
• The nervous system of
molluscs seems to be
wide range of
complexity.
• Moreover of single
brain, the molluscs have
a set of “Local Brains”.
9

10. Nervous System and Behaviour (con’t)
• In cephalopods, complexity of the nervous
system reaches its highest point, then
separates local brains are fused into a
single large brain that coordinates and
stores information received from the
environment.
10

11. Nervous System and Behaviour (con’t)
• Most cephalopods, especially cuttlefishes,
display color changes correlated with
particular behaviours and moods for their
hiding.
• Mostly of the cuttlefishes flash two large
black spot resembling eyes.
11

12. Reviews
• Scientific classification
o Kingdom : Animalia
o Super phylum: Lophotrochozoa
o Phylum: Mollusca
• Classified by Carl Linnaeus in 1758
(Sweden)
• 85,000 Recognized living species.
12

13. snail slug
oyster clam
octopus squid
13
Group 1 slide

14. Reproduction of Mollusc
• Mollusk use sexual reproduction to pass
on there genes. (Male and Female)
• Exception of some snails that are
hermaphroditic.
• Some organisms such as oysters change
there sex many time throughout their life.
• All are produce eggs.
14

15. Oyster Life Cycle
15

16. Reference
• Castro Huber, 1997. Marine Biology (third edition)
• https://en.wikipedia.org/wiki/Mollusca
• http://study.com/academy/lesson/definition-
formation-features-types.html
• http://oceanservice.noaa.gov/facts/.html
• www.botos.com
• https://en.wikipedia.org/wiki/Mollusca
• https://www.nsta.org/publications/press/extras/files
/nexttime/MolluskAdaptations.pdf
16

17. Thank You for Your Paying
Attention!!!
Q & A
17