Transcript 10-1 Mollusks

Warm Up
Is a snail’s shell like a coral reef? Explain
your answer.
Mollusks, Arthropods, and
Echinoderms
Mollusks
Chapter 10
Section 1
Discover Activity
• How can you classify shells? Page 328
Objectives:
• To identify the main characteristics of
mollusks.
• To describe the major groups of mollusks
and tell how they differ
• Many seafoods you are familiar with are
members of the phylum Mollusca. These
include: clams, oysters, and mussels.
• Mollusks are soft-bodied animals that
typically have inner or outer shells.
Structure
• Mollusks have a thick, muscular foot which they
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use to open and close shell, move, or bury
themselves.
The head region of a mollusk usually contains a
mouth and sense organs like eyes.
The rest of the body contains organs for
processes such as digestion, circulation,
respiration, or reproduction.
A soft mantle covers much of mollusk’s body.
This makes the material that creates the shell
• Mollusks are divided into groups according
to characteristics:
a. Presence of a shell
b. Type of shell
c. Type of foot
The three main groups of mollusks
are:
1.
2.
3.
Snails and slugs -- Gastropods
Two shelled mollusks -- Bivalves
Tentacled mollusks -- Cephalopods
Gastropods
• The largest group of mollusks is animals that
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have a single shell or no shell at all.
Two examples of these would be slugs and
snails.
Gastropod means foot-stomach. They move by
means of a foot that is near their stomach.
Gastropods have a radula that is a file-like
tongue that cuts off pieces of plants.
Slugs are gastropods that do not have a shell.
http://www.enchantedlearning.com/s
ubjects/invertebrates/mollusk/gastro
pod/Snailprintout.shtml
http://www.enchantedle
arning.com/subjects/inv
ertebrates/mollusk/gast
ropod/Snailprintout.sht
ml
Species Achatina fulica (giant african snail)
Achatinella
Brown-lipped snail (Cepaea nemoralis)
http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Gastropoda.html
Cerithiumsp., India
Haminoea linda, South Pacific
Cerithium sp., India
glossy pillar
Cochlicopa lubrica, Michigan
http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Gastropoda.html
rosey wolfsnail
Euglandina rosea
dusky ancylid
Laevapex fuscus
Gastrocopta, Michigan
escargot
Helix pomatia
http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Gastropoda.html
white-lip globe
Mesodon thyroidus
Unidenified Nembrotha species
Batangas, south Luzon, Philippines
big-eared radix
Radix auricularia
http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Gastropoda.html
Volutidae
unidentified sea slug
Nudibranchia
Bunakin National Park, Indonesia
http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Gastropoda.html
unidentified sea slug
Nudibranchia
Bunakin National Park, Indonesia
http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Gastropoda.html
giant garden slug
Limax maximus
http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Gastropoda.html
Ariolimax columbianus Banana Slug
Arion
http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Gastropoda.html
For all pictures taken from the above website:
Citation: Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S.
Hammond, and T. A. Dewey. 2006. The Animal Diversity Web
(online). Accessed November 26, 2006 at
http://animaldiversity.org.
Sponsored in part by the Interagency Education Research
Initiative, the Homeland Foundation and the University of
Michigan Museum of Zoology. The ADW Team gratefully
acknowledges their support.
©1995-2006, The Regents of the University of Michigan and its
licensors. All rights reserved.
Bivalves
• Two shelled mollusks are bivalves. Examples
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would be oysters, clams, and scallops.
These animals have two shells held together by
a powerful muscle.
Bivalves are filter-feeders, which means as water
passes over their bodies they filter out small
particles.
A pearl is created in a bivalve when a foreign
object inside the bivalve irritates the mantle and
its coats the object.
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Bivalvia/v02_id345_con_bivanat.jp
g/view.html
Tubba-taha reef, Sulu Sea, Philippines.
This particular variety of clam (Tridacna species), with its brilliant blue mantle, is a common sight on
shallow Philippine reefs. It measures about six inches from end to end. In this photo the fleshy mantle
is entirely exposed, but patience is required to see the clam in this state-- the clam will abruptly close
its shell with only a minor change in light, such as a shadow. Specialized cells called ocelli along the
outer edge of the mantle are responsible for light reception.
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Bivalvia/v02_id345_con_bivanat.jp
g/view.html
Giant clam species (Tridacna), captive.
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Bivalvia/v02_id345_con_bivanat.jp
g/view.html
bivalves and clams
Bivalvia
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Bivalvia/v02_id345_con_bivanat.jp
g/view.html
Bivalves dislodged from beneath a single rock in a coral lagoon in the South
Pacific. Included are pen shells, pearl oysters and a young Tridacna. Note the
bivalve with its inhalant (ventral) and exhalant (dorsal) siphons extended
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Bivalvia/v02_id345_con_bivanat.jp
g/view.html
spike
Elliptio dilatata
tubercled blossom
Epioblasma torulosa
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Bivalvia/v02_id345_con_bivanat.jp
g/view.html
plain pocketbook
Lampsilis cardium
creek heelsplitter
Lasmigona compressa
wabash pigtoe
Fusconaia flava
three-horn wartyback
Obliquaria reflexa
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Bivalvia/v02_id345_con_bivanat.jp
g/view.html
salamander mussel
Simpsonaias ambigua
peaclams
Pisidiidae
mapleleaf
Quadrula quadrula
pimpleback
Quadrula pustulosa
deertoe
Truncilla truncata
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Bivalvia/v02_id345_con_bivanat.jp
g/view.html
Cephalopods
• The most developed mollusks are the tentacled
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mollusks, or cephalopods.
Examples would be octopuses and squid.
Most cephalopods do not have an outer shell,
but have part of a shell within their bodies.
Cephalopods use their tentacles to move and
capture food.
They also move by using a form of jetpropulsion.
They can also release an ink that helps to hide
them from predators.
Octopodidae
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Bivalvia/v02_id345_con_bivanat.jp
g/view.html
Octopodidae
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Bivalvia/v02_id345_con_bivanat.jp
g/view.html
blue-ringed octopus
Hapalochlaena maculosa
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Bivalvia/v02_id345_con_bivanat.jp
g/view.html
Hapalochlaena lunulata, a blue-ringed octopus
The photographs of H. lunulata were shot by Roy Caldwell.
http://www.thecephalopodpage.org/lunulata.php
Octopus
rubescens, the Red
octopus
Octopus macropus
http://www.thecephalopodpage.org/lunulata.php
Octopus salutii
Tremoctopus violaceus,
a gelatinous octopus
http://www.thecephalopodpage.org/lunulata.php
A cuttlefish (Sepia latimanus). The behavior shown, with
two of its tentacles raised, is typical of a posture assumed
just before lashing out with whip-like appendages to
capture prey.
Cuttlefish are curious-- this one stayed
around for a look at me, though it could
have easily "jetted" away with its siphon.
The safest position for it is just as seen
here; since its siphon is pointed toward
the threat (me), its direction of movement
would be away from the camera.
Cuttlefish can change colors faster than
a television screen. Their "bones", the
inner chitonous skeleton, often wash up
on the beach, and are frequently sold in
pet stores for parakeets and other birds
to sharpen their beaks.
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Bivalvia/v02_id345_con_bivanat.jp
g/view.html
This cuttlefish, about two feet in length, is staring inquisitively at me as I caught it in the
beam of a small spotlight on my strobe. At night, the protective coloration is less useful,
so the cuttlefish apparently hasn't made its mind up about what color or texture to
assume. This one was seen over a large expanse of white coral sand.
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Bivalvia/v02_id345_con_bivanat.jp
g/view.html
Sepia officinalis, the Common Cuttlefish
Sepioloidea lineolata, the Striped pyjama squid
Sepia pharaonis, the Pharaoh Cuttlefish
http://www.thecephalopodpage.org/lunulata.php
Sepioloidea lineolata,
the Australian Giant Cuttlefish
http://www.thecephalopodpage.org/lunulata.php
Euprymna scolopes, Hawaiian bobtail squid
http://www.thecephalopodpage.org/lunulata.php
Euprymna tasmanica, Southern Dumpling squid
http://www.thecephalopodpage.org/lunulata.php
Rossia pacifica, Stubby squid
Loligo forbesi, Veined squid
http://www.thecephalopodpage.org/lunulata.php
Vampyroteuthis infernalis,
Deep-sea Vampire squid
Architeuthis, Giant squid
Illex illecebrosus, Short-finned squid
http://www.thecephalopodpage.org/lunulata.php
Sepioteuthis sepioidea, Caribbean Reef squid
http://www.thecephalopodpage.org/lunulata.php
Sepioteuthis sepioidea, Caribbean Reef squid
http://www.thecephalopodpage.org/lunulata.php
Sepioteuthis sepioidea, Caribbean Reef squid
http://www.thecephalopodpage.org/lunulata.php
Nautilus pompilius, Nautiluses
http://www.thecephalopodpage.org/lunulata.php
http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Gastropoda.html
For all pictures taken from the above website:
Citation: Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond,
and T. A. Dewey. 2006. The Animal Diversity Web (online). Accessed
November 26, 2006 at http://animaldiversity.org.
Sponsored in part by the Interagency Education Research Initiative, the
Homeland Foundation and the University of Michigan Museum of Zoology.
The ADW Team gratefully acknowledges their support.
©1995-2006, The Regents of the University of Michigan and its licensors.
All rights reserved.
Homework
• Workbook pages 137 - 140