1. Why they are related to annelids
Mollusks
Soft body with internal or external shell
Trochophore-free-swimming larval stage
Why they are related to annelids
True coelom

2. Body Plan Foot- can be flat, spade, tentacles
Mantle- outer layer of tissue covering body
Shell- calcium carbonate
Visceral Mass- internal organs

3. Feeding-herbivores, carnivores, filter, detrivores
Radula-snails & slugs, tongue with teeth
Poisons-octopi
Gills-clams, oysters, scallops
Siphon- allows water in and out to go over gills
Respiration-aquatic-gills
Land-exchange with blood vessels
Circulation-open-blood moves from vessels to sinuses (slower animals)
Or closed-octopi
Excretion-nephridia-remove ammonia
Radula

4. Response- varies greatly
Clams-very small amount of nerves
Octopi- well-developed brain, intelligent
Movement-mucus on foot, jet propulsion
Reproduction-sexual through external or internal fertilization
Some are hermaphrodites
Octopus opening jar:

5. 1. Polyplacophora- chitons
fossil record, stretching back 400 million years to the Devonian
live on hard surfaces, such as on or under rocks
Only marine
Body is a series of overlapping plates

6. 2. Gastropoda-snails, slugs, sea butterflies, sea hares, limpets, nudibranchs
Shell-less or single shelled
Radula, head with tentacles
Open circulatory system

7. 3. Bivalvia- clams, oysters, mussels, scallops
2 shells with hinge
No radula, use filter
Oysters & mussels-sessile
Pearls- made when something (sand) gets trapped between mantle & shell, so mantle secretes shell-like material

8. 4. Cephalopoda- squid, octopi, nautiluses, cuttlefish
Head attached to single foot (divided into tentacles)
Small internal shells or no shell
External shell- nautilus
Squid- internal supporting rod (pen)
Complex sense organs- sharp vision
Closed circulatory- efficient for constant blood supply to muscles
nautilus
cuttlefish

9. Octopus Facts
All are venomous, but only the small blue-ringed octopuses are deadly to humans. a neurotoxin which is also found in pufferfish that is 10,000 times more toxic than cyanide. Tetrodotoxin blocks sodium channels, causing motor paralysis and respiratory arrest within minutes of exposure, leading to cardiac arrest due to a lack of oxygen. The toxin is produced by bacteria in the salivary glands of the octopus.
An octopus has a hard beak
They swim at 25 mph, but feels like 60mph
Most don’t have a shell, some have remnants of internal shell

10. Both squids and octopuses have blue blood
Both squids and octopuses have blue blood. Their blood is this color because they use an oxygen-carrying molecule in their blood that contains copper.
short life expectancy, and some species live for as little as six months
Octopuses have three hearts. Two branchial hearts pump blood through each of the two gills, while the third pumps blood through the body
Have a memory system and even play
Ink- melanin to distract predator
Smell with arms, some can regenerate if lost
Can change color & shape
Males lose their penis while mating & regenerate it the next year, females die after mating
Squids have pens & 2 tentacles

11. Inking Shape & color change Mimic
Shape & color change
Mimic