Download Phylum Mollusca - My Teacher Pages

Intro to Molluscs
• http://shapeoflife.org/video/molluscssurvival-game
Opening Assignment
• PUT YOUR PHONE AWAY 
• Turn in your study guide for the Unit 5 test
if you have not already done this.
• Get a piece of paper out and label it
“Mollusc Trivia Quiz” 1-5
Unit 6: Phylum Mollusca,
Arthropoda, & Echinodermata
Phylum Mollusca Trivia
True or False
1. There are snails that can kill people.
2. Some oysters change their sex from year
to year.
3. All gastropods have shells.
4. An acre of mussels produces more meat
than an acre of pastureland that cows
graze on.
5. The largest gastropod was 2 ½ feet long
and weighed 40 pounds.
TRUE
1.
There are snails that can kill
people.
•
•
Pretty Dangerous
Beautiful yet deadly, cone snails mostly inhabit
the shallow tropical waters of coral reefs or
mangrove swamps. They harpoon other
invertebrate prey with a concealed hollow tooth,
through which they inject conotoxin venom. The
venom is a mixture of different toxic protein
molecules, of which each species might possess
100 varieties. Constantly revising that recipe
makes it more difficult for prey to evolve
resistance.
Cone snail shells come in a dazzling array of
colors and patterns, said the letter's co-author,
ecologist Callum Roberts at the University of
York in England. "But as swimmers who made
the mistake of tucking an attractive shell into
their costume have found out, they produce a
powerful venom." That poison is strong enough
to paralyze or kill a person.
•
TRUE
2. Some oysters
change their sex
from year to year.
• They are sequential
hermaphrodites
(different from being
able to produce both
sperm and eggs at
the same time).
FALSE
3. All gastropods have
shells.
• Nudibranchs are
gastropods that
don’t have shells.
Instead they use
toxins and bright
warning coloration
for protection.
TRUE
4. An acre of mussels produces more meat than
an acre of pastureland that cows graze on.
• Mussels produce 10,000 pounds of meat, cows
only produce 200 pounds!
TRUE
5. The largest
gastropod was 2 ½
feet long and
weighed 40 pounds.
• The Horse Conch is
the largest
gastropod, and it
lives in our area!
Have you seen one?
Day 1 Activities
• Read the Marine Biology book pages 124130 and answer the questions on
Molluscs.
• When you are finished you can turn your
paper in to the bin. 
Phylum Mollusca Questions Pages 124-129
Copy and complete the following questions.
Molluscs: The Successful Soft Body
1. Describe the body plan of a mollusc.
2. How do molluscs move?
3. What is a radula?
4. List the major characteristics of each of the types of Molluscs - Gastropods,
Bivalves, and Cephalopods including
A. Their class
B. what makes them unique,
C. most common organisms,
D. what and how they eat
E. Something unique about their behavior
Biology of Molluscs
1. Explain the basic digestive system of all molluscs.
2. How are Gastropod and Bivalve brains different than other molluscs.
3. Explain the differences in how the three types of molluscs reproduce.
Opening Assignment
• List the levels of classification from domain to
class for gastropods.
• List the 3 classes of Molluscs you have read
about and give an example of an organism in
each class.
• HINT – YOU MAY SEE THESE AGAIN ON THE
OPEN NOTES QUIZ NEXT WEEK!
• P.S. OPEN NOTES QUIZZES ARE NOT
MULTIPLE CHOICE 
Unit 6 Student Learning Goals
Students will be able to
• Describe the structure and function of the
main types of molluscs, arthropods, and
echinoderms.
• Explain how each of those play a role in
the health of the marine ecosystem.
Part 1: Phylum Mollusca
(Latin “mollis” means “soft bodied”)
Common names: Clams, squid,
snails…
General Characteristics
• One of the largest and most diverse groups on
invertebrates
• Bilateral symmetry
– Body can be divided in half along ONLY one line
• More complex than cnidarians because tissues
form distinct organs (ex. stomach, gills)
• Complete digestive system with two openings
(mouth and anus)
Anatomy
• Basic body plan: Head/ foot/ visceral mass
– Head- region with sensory capabilities
– Foot- muscular region used for locomotion or
attachment
– Visceral mass- region that contains organs
What makes a mollusc a mollusc?
Mantle: Protective tissue that covers body (and
secretes shell)
What makes a mollusc a mollusc?
Radula (EXCEPT Bivalves): Ribbon of tissue
that is covered with teeth, used for feeding
What makes a mollusc a mollusc?
Muscular foot
Used for locomotion and attachment
May be modified into tentacles (squid, octopus,
nautilus)
Types of Molluscs:
• Remember classification:
Kingdom Animalia
Phylum Mollusca
Class …
Gastropoda
Bivalvia
Cephalopoda
Class Gastropoda
(Snails & Nudibranchs)
– 75,000 species, mostly marine
– Coiled shell or no shell (nudibranchs)
– Most move slowly using foot to creep
– Marine gastropods can be herbivores, detritus
feeders, carnivores, scavengers or parasites
• Gastropods usually have a well-defined
head with two or four sensory tentacles, a
calcium carbonate shell, usually spirally
coiled into which the body can be pulled
back, and a muscular foot on their lower
surface.
Gastropods continued . . .
• Many marine gastropods burrow and have a
"siphon" extending out from the edge of the
mantle . The siphon allows the animal to draw
water into their mantle cavity and over the gill.
They use the siphon mainly to "taste" the water
to detect prey from a distance.
Gastropods continued . . .
• Most Gastropods have a muscular
crawling, flat foot used for (slow)
movement. Some species use the foot to
dig, other species, like the nudibranchs,
are free swimming.
Gastropods continued . . .
Gastropod Reproduction . . .
• Most marine gastropods have separate
sexes whilst terrestrial gastropods are
usually hermaphrodites (posessing both
male and female reproductive organs).
• They reproduce in various ways based on
the species including internal and external
fertilization and then larvae formation.
Class Gastropoda
(Snails)
Class Gastropoda
(Nudibranchs) Video Clip
Deadly Cone Snails
• https://www.youtube.c
om/watch?v=JjHMGS
I_h0Q
Class Bivalvia
(Clams, oysters, scallops, mussels)
– Body enclosed in two valved shell (two half
shells) that are joined by a hinge
– No defined head or radula
– Filter feed using gills
– May burrow in sediment (clams), attach to
substrate (oysters & mussels) or “swim”
(scallops)
Bivalves continued
• The foot of bivalves is adapted for
burrowing in all species except the
sedentary ones, where it is reduced in
size.
• Some species, e.g., the cockles, use the
foot to hop about from place to place.
Bivalves continued
• Bivalves have a greatly reduced head and
no radula.
• Most have a single pair of large gills used
for respiration and for trapping minute food
particles.
Bivalves Nervous System
• Bivalves have a relatively simple nervous
system with three pairs of ganglia and two
pairs of long nerve cords.
Bivalve Reproduction
• Bivalves usually require both males and
females to reproduce, although some
species individuals either have the organs
of both sexes or start out as males and
later become females.
• Bivalve eggs and sperm are usually
released into the water, where fertilization
takes place. The eggs hatch into veligers
(VEL-ih-jerz), or young, that live among
and eat other plankton.
Bivalve Anatomy
Class Bivalvia
(Clams, oysters, scallops, mussels)
Bivalves are AWESOME!
• https://www.youtube.c
om/watch?v=tIOSWA
bUf74
Class Cephalopoda
(Octopus, squid, nautilus, cuttle fish)
– ONLY marine
– All predators
• Foot modified into tentacles with suckers
• Beak-like jaws
– Body specialized for locomotion
• Mantle forms a siphon that is used to expel water
for jet propulsion
• Shell reduced or absent
– Advanced nervous system
• Large brain with complex eyes
• Specialized cells called chromatophores used to
change color for camoflage
Cephalopods continued . . .
• Sex and reproduction in cephalopods is in many ways quite
different than in other molluscs. First, sexes are separate
and mating usually includes a courtship that often involves
elaborate color changes. This is followed by the transfer of a
spermatophore (sperm packet) by a male to a female
through her mantle opening. The spermatophore is
transferred by the male using either a penis or a modified
arm called a hectocotylus. Most females then lay large yolky
eggs in clusters on the ocean floor or on any other hard
substrate. Eggs develop by dividing unequally instead of in
the spiral pattern of other molluscs. It is thought this is a
derived mode of development. After a period of development
within the egg, juveniles hatch out directly without the
swimming larval stage common to many other molluscs.
Most males and females die shortly after spawning
Cephalopods continued . . .
• Cephalopods are the most intelligent, most
mobile, and the largest of all molluscs.
Squid, octopuses, cuttlefish, the
chambered nautilus, and their relatives
display remarkable diversity in size and
lifestyle with adaptations for predation,
locomotion, disguise, and communication.
Squid Anatomy
Octopus Anatomy
Class Cephalopoda
(Octopus, squid, nautilus, cuttlefish)
Cephalopod Video
https://www.youtube.com/watch?v=1VjxvrXGEHk
Class Cephalopoda
(Octopus, squid, nautilus, cuttlefish)
•
•
•
•
•
Octopus camo
Octopus escape
Octopus vs. Shark
Mimic Octopus
Flamboyant Cuttlefish
Opening Assignment
1. What type of symmetry do mollusks
have?
2. List the 3 parts of the general body plan
of a Mollusc.
3. Which of these body parts is absent in
bivalves?
4. List the 3 characteristics that make a
Mollusc a Mollusc.
Opening Assignment
1. What type of symmetry do mollusks
have? Bilateral Symmetry
2. List the 3 parts of the general body plan
of a Mollusc. Head, Foot & Visceral
Mass
3. Which of these body parts is absent in
bivalves? No head
4. List the 3 characteristics that make a
Mollusc a Mollusc. Mantle, Radula,
Muscular Foot
Phylum Mollusca Mini Project
Part 1: Choose a species from the class of molluscs that you were
assigned. Research the information below and answer the questions
using complete sentences in a paragraph format. (70%)
1.What is the scientific name of your species? List the levels of classification
2.What does your species eat? Does anything eat it? (use vocab. Herbivore,
carnivore, omnivore, predator, prey)
3.How does it reproduce?
4.What ocean and ocean zone does it primarily live in? (benthic, neritic,
aphotic . . . )
5.What adaptations does your species have and how does it help it survive?
6.What is the lifespan of your organism?
7.What makes your organism awesome?
Part 2: Create! Draw or print a picture of your species and label the main
parts. (30%)
Open Notes Quiz Tomorrow
• Don’t forget to bring your Mollusc
questions that were graded and handed
back to you and also your Mollusc guided
notes.
• This quiz will be open notes but NOT
multiple choice.
Opening Assignment
• Get your notes out and ready for the open notes
quiz today. You may use your opening assignment
notes, the Phylum Mollusca textbook questions,
and the guided notes to help you.
• Answers MUST be in complete sentences or I will
deduct points. Use the back of the paper if needed
– be as complete in your answers as you can.
• Staple your guided notes and Phylum Mollusca
textbook questions to your test when you turn it in.
Phylum Arthropoda Textbook questions
Phylum Arthropoda Textbook Questions - Marine Biology Textbook
Arthropods: The Armored Achievers (pg. 130)
1. How many species of arthropods are known? How many are still undiscovered?
2. Give 3 examples of marine arthropods.
3. Describe the arthropod body.
4. What is the function of the exoskeleton and jointed appendages in an arthropod?
5. Explain the process that takes place when an arthropod grows.
6. Why are most arthropods small in size?
7. What are crustaceans?
8. How do crustaceans get oxygen?
9. What do crustaceans use their antennas for?
Biology of Crustaceans pg. (133-134)
1. Describe how the feeding of copepods is different than the feeding of larger
crustaceans like lobsters.
2. Where does gas exchange happen in crustaceans?
3. Describe the nervous system of the crustacean including the brain, eyes, and their
sense of smell.
Phylum Arthropoda
Greek means…
“jointed foot”
Common names: crab, lobster,
barnacles, shrimp, crawfish,
horseshoe crab
General Characteristics
• Invertebrates
• Largest animal phylum
• Phylum includes all insects, spiders and
scorpions
• Most can regenerate lost appendages
• Keen sense of smell- chemoreception
Anatomy
• Bilateral symmetry
• Basic body plan includes
3 main body sections:
head, thorax and
abdomen
• Head and thorax are
combined and known as
the cephalothorax
• Cephalothorax is
protected by hard outer
covering called a
carapace
What makes an Arthropod an
Arthropod?
• Jointed appendages
• Exoskeleton
– Made of chitin (like your fingernails)
– Does not grow with the animal
• Molting
– Process of shedding the exoskeleton so that the
animal can grow bigger
– Immediately after molting the animal is “soft shelled”
until the new exoskeleton is hardened
Types of Arthropods
There are many classes within phylum
Arthropoda, but I will limit our study to
just 2 that are VERY important in the
marine environment
Class Crustacea
shrimp, lobster, true crabs and
barnacles
– Primarily aquatic - mostly marine
– The only Arthropods with 2 pairs of antennae
– Usually have eyestalks
– Larvae make up large amount of plankton
Crustaceans
Largest land dwelling crustacean
• Coconut Crab
Largest marine crustacean
• Japanese
Spider Crab
•
Giant Japanese Spider Crab.
Natural habitat 50-300 metres
below sea level in the Pacific
Ocean near Japan. They can
weigh 16-20 kg, and span over 3
m outstretched clawtip to
clawtip. Taken at the Sealife
aquarium, Scarborough.
Class Merostomata –
Horseshoe crabs
– Not true crabs - doesn't have typical
crustacean characteristics - gets name from
shape of exoskeleton
– One of Earth's oldest creatures (here 100 mill.
yrs before dinosaurs)
– More closely related to scorpions and spiders
than true crabs
– Have blue blood (contains copper)
– Extremely important to survival of migrating
shorebirds
Horseshoe crabs
Where do arthropods live?
• Worldwide distribution
and habitats
• Mostly benthic
(bottom dwelling)
• Some are sessile
(barnacles)
What do arthropods eat?
• Mostly scavengers (eat already dead or
decaying organisms) but can be
predators (hunt and kill prey) also
– Voracious Phronima
How do arthropods reproduce?
• Only sexual reproduction
• Internal or external fertilization
– Remember, many crustaceans brood their eggs, then
release the planktonic larvae
• Mostly dioecious, however some (like
barnacles) are hermaphrodites
Arthropod Behavior
• Complex behavior
• Spiny lobster
migration
• Use wide variety of
signals to
communicate with
each other for territory
or courtship
• Fiddler crab waving
Let’s talk about barnacles
• What do we know about them so far?
– Sessile
– Hermaphrodites
• How do you think they reproduce?
• Well, actually… Barnacles Tell No Lies
Arthropods
• https://www.youtube.com/watch?v=SvI_5
CvKJEU
Opening Assignment - Arthropods
Can you answer these without your notes?
1. List 3 similarities between phylum mollusca
and phylum arthropoda.
2. What does arthropoda mean in Greek?
3. What restricts arthropods from growing larger?
How do they overcome this?
4. What is the cephalothorax? What is it covered
by?
5. What 3 features make arthropods unique
compared to the other phyla we have studied?
Opening Assignment - Arthropods
Can you answer these without your notes?
1.
•
2.
•
3.
•
4.
•
5.
•
List 3 similarities between phylum mollusca and phylum
arthropoda.
Invertebrate, Bilateral symmetry, sexual reproduction only
What does arthropoda mean in Greek?
Jointed foot
What restricts arthropods from growing larger? How do
they overcome this?
Exoskeleton, the process of molting
What is the cephalothorax? What is it covered by?
Region in crustaceans, combined head and thorax.
Covered by the carapace
What 3 features make arthropods unique compared to the
other phyla we have studied?
Jointed appendages, exoskeleton, molting