1. PHYLUM MOLLUSCA

2. Of all the legendary sea monsters - sea serpents, giant squid,
man-eating clams and huge otocopuses- which one really exist?
A young boy , Tom Squires, and his father and a friend set out of
Conception Bay, Newfoundland, for a day a squid jigging.
Their dory bumped a sleeping giant squid, which immediately wrapped
tentacles around the dory and became decidedly grumpily about their
little accident.
The two men were petrified with fear but the 12 year old boy grabbed
a heavy fish knife and hacked off part of a tentacle.
The squid released the boat. The section of the tentacle left around the
boat was reliably measured at 19 feet 6 inches.
Estimate the length of a squid that could have a 19.5 foot long tentacle.

3. WHAT IS A MOLLUSK?
Why are animals that look and act so different grouped in the same phylum? It is because they share developmental patterns.

4. Characteristics of Mollusk
1. mantle
2. mantle cavity
3. shell
4. true coelom
5. head, muscular foot, visceral cavity
6. systems: circulatory, respiratory, digestive, excretory, reproductive, and nerve impulses

5. Mollusks are well defined as soft bodied animals that either have an
external or internal shell.
Their name comes from the Latin word molluscus meaning soft.

6. Most mollusks are composed of 4 basic parts:
foot - flat surface adapted for locomotion and usually contains the mouth and other feeding structures
mantle - covers most of the body and secretes the shell
shell - composed of calcium carbonate
visceral mass - contains the internal organ

7. Unique features of most mollusks include
Mantle
ctendia - special gill which are also used for filter feeding
radula - rasping tongue-like structure used for scraping

8. INTERNAL TRANSPORT
OPEN CIRCULATORY SYSTEM
In open circulatory systems, the blood is not always contained in vessels. There is a simple heart and a few arteries but there are no veins. Blood leaves the heart and bathes the internal organs and travels through the body in open spaces called sinuses. These sinuses lead the blood to the gills where oxygen and carbon dioxide are exchanged (diffusion).

9. What is a closed circulatory system?

10. Excretion -
All animals must remove waste products An open circulatory system will work well for slow
moving animals. Why is an open circulatory system not adequate for fast-moving animal