Transcript unit 4b echinoderms 2012

Unit 4B
Journal #1 3/27
• Trace the path of water through the water
vascular system.
• What would happen to a starfish that had a
mutation that caused the stone canal to be
deformed?
Unit 4B
Journal #1 10/23
• What do these animals have in common?
Unit 4B
3/26
• Please turn in your mollusk essay with
rubric and pick up:
– Purple echinoderm unit sheet
– Echinoderm study guide
– Sea star structure/function activity
Unit 4B
Journal #2
3/30
• Starfish eat oysters. Oyster farmers use to
scuba dive down and cut up the starfish to
kill them. Explain why this was NOT an
effective method to kill the starfish.
Journal: What
Phylum
do all of these
organisms
have
Echinoin common?
dermata
Journal
• Get an iRespond remote and complete Journal.
• Use these words in a sentence related to one of the
animals we’ve discussed this school year. Can you
combine some of these so you don’t have to write 5
separate sentences?
–
–
–
–
Germane- relevant
Ignominious- shameful
Imminent- dangerous, close at hand
Factious- turbulent
1. What is the seive plate that filters water before it enters the
water vascular system?
a. Madreporite
b. Pyloric caeca
c. pedicellaria
2. Another name for the pyloric caeca is
a. Intestine
b. Anus
c. gonad
3. The pinchers on top of the body that are used to free skin of
debris are called
a. Madreporites
b. Pedicellaria
c. Tiedeman bodies
4. What is responsible for movement, respiration, and
circulation.
a. Pyloric caeca
b. Nervous system
c. Water vascular system
5. Which side of the starfish is shown?
a. Oral
b. aboral
General Information
1.
Echinoderm- “spiny skin”
2.
Have water vascular system
3.
Do not have true
circulatory, respiratory, or
excretory system
4.
Pentaradial symmetrybody parts arranged in fives
or multiples of fives around
an oral (mouth) and aboral
(anus) surface.
Classification
1. Kingdom Animalia
2. Phylum Echinodermata
3a. Class Asteroidea
3b. Class Echinoidea
3c. Class Ophiuroidea
3d. Class Holothuroidea
3e. Class Crinoidea
IIIa. Class Asteroidea (sea stars)
A. Structure/Support
1. Endoskeletona. calcium carbonate
plates called ossicles.
b. Spines- deter predators
2. Pedicellaria- pinchers
for protection & for
keeping aboral surface
clean of debris.
A. Structure/Support
3. Central disk- center
part of starfish
4. Ambulacral groovegroove thru which
tube feet stick out
Oral (ventral) surface
Aboral (dorsal) surface
Central
disk
Arm/Ray
Spine
B. Water Vascular System- movement, respiration, circulation, some
excretion
1. Madreporite on aboral surface.
2. Stone canal
3. Ring canal
4. Ring canal has Polian vesicles attached that allow for
storage of water.
5. 5 radial canals, one in each ray.
6. Water enters hundreds of bubble-like sacs called the
ampulla which inflate.
7. Muscles are stimulated which contract ampulla and push water
down a tube to the suction cup-like tube foot.
8. The tube foot attaches to a surface creating movement.
c. Digestion/Feeding
1. Mouth is on oral surface (underneath)
2. Use rays & tube feet to grasp prey (clams)
3. Opens shell 0.1mm, enuf to insert cardiac stomach.
4. The pyloric caeca (digestive glands) release digestive
enzymes that begin to dissolve prey.
5. As the digestive enzymes work, the clam muscles weaken,
making it easier to open.
6. Partially digested food is taken to the pyloric stomach
where it is absorbed and nutrients are passed to the pyloric caeca
which transport nutrients throughout.
7. Wastes leave thru the aboral surface thru anus.
8. This process can take up to 8 hours depending on size of clam!
D. Respiration/circulation
1. Breathe via
a.
Tube feet
b.
Dermal gills- aboral
surface
2. No blood or
circulatory system
Excretion
1. Tiedemann’s bodies(in ring canal) filter water
of debris
2. Amoebocytes- collect
debris & bodily wastes &
excrete thru dermal gills.
F. Nervous/sensory system1. Nerve ring around
mouth
2. Radial nerves in each
arm (coordinate tube feet)
3. Photosensitive eyespots
at tip of each ray
G.Reproduction
1. Asexual- regeneration
a. Can take up to a year
b. Some broken arms can regenerate
entire body if central disk is attached
2. Sexual- dioecious
a. Gonads (ovaries-red, testeswhite) in each ray
b. External fertilization
c. Gametes released thru
gonopore at base of each arm
d. Release pheromones to
induce gamete release among
other starfish in area for
spawning.
e. Larvae (bipinnaria) live
amongst plankton until adult
organs grow
IIIb. Class Echinoidea
1. Ex: sea urchins & sand dollars
2. Globe or disc shaped
3. No rays
4. Movable, hollow
spines- may be
venomous
5. Skeleton of 10
ossicle plates- test
6. Digestion- chewing
mouth called aristotles
lantern
7. Eat algae, coral,
dead animals
8. Water vascular
system, tube feet
9. Habitat- rocks,
sand, mud,
shallow water
IIIc. Class Ophiuroidea
1. Ex: brittle stars
2. Long narrow arms
3. Habitat- rocks, coral
4. Predators & scavengers
5. Use arms & tube feet in
sweeping motion to collect
prey which is then transferred to the
mouth.
IIId. Class Holothuroidea
1. Ex: sea cucumbers
2. No rays
3. Elongate body
4. Circumoral tentacles
(surround mouth)
5. No spines or pedicellaria
6. “earthworms of the sea”- feed on
detritus & turn over ocean soil
7. Digestion- food trapped in net-like
tentacles which are “licked” clean by
mouth.
8. Evisceration- eject mass of visceral
organs when disturbed. Confuses
predator.
IIIe. Class Crinoidea
1. Ex: sea lilies & feather stars
2. Usually sessile
3. Have fan-like appearance
4. Filter feeders
Environmental/Economical
Significance
• Sea urchin spines are poisonous if
stepped on.
• Sea urchin gonads are a delicacy in
Asia.
• Sea cucumbers are dried & eaten
• Sea cucumber toxin used to kill tumor
cells (may fight cancer)
• Starfish are pests in oyster beds
• Echinoderm carbonate skeletons can
be ground up and used as lime to
enrich soil
• Source of food for many organisms in
food web
• Decorations