Invertebrates
6.L.4
Classifying Animals
1.
2.
3.
4.
During this unit we will look at 4 major ways to classify animals.
Structures- what features do these animals have (vertebrate or
invertebrate/ ectothermic or endothermic/ bodily systems)?
Resources- how do these animals obtain food and how do they get
oxygen?
Movement- How do these animals move and for what purpose?
Reproduction- by what means do these animals reproduce?
Sponges
Phylum: Porifera
Invertebrate
• A sponge is an invertebrate, meaning it
has no backbone or internal skeleton.
• They are made of a jelly-like substance
that is surrounded by a tough outer
membrane (skin)
• Some have spines for protection from
predators
Sponge
Structures
• Filter Feeder - The membrane has
many pores that filter water and allow
the sponge to obtain resources (food,
oxygen, and other nutrients)from the
ocean.
• The water is then released, along with
waste, through a tube in the top of the
sponge, called the osculum.
Sponge
Resources
Sponge- Movement
Most sponges do not
move. They attach
themselves to a solid
surface.
A few sponges actually
move at the amazing speed
of 1-4 millimeters per day!
Sponge Reproduction
*Sponges reproduce
sexually by releasing sperm
cells that are absorbed by
other sponges
* also asexually by budding.
SPONGES REPRODUCE
BOTH WAYS! ….COOL,
RIGHT?
Sponge releasing sperm
cells
A sponge
producing
a bud
osculum - the large
openings in a
sponge through
which water flows
out of the sponge
epidermis - the layer
of cells that covers
the outer surface of
the sponge
holdfast - root-like tendrils that
attach the sponge to rocks
water flows in water flows into a
sponge through
pores (holes)
located all over its
body. The sponge
obtains its
nutrients and
oxygen by
processing this
flowing water
Sponge Lab
Focus Question- Will a natural sponge or a synthetic sponge absorb more water?
Hypothesis: I predict that the ___________ sponge will
filter more water because…
Amount of water absorbed (mL)
Trial 1
Natural Sponge
Synthetic Sponge
Trial 2
Trial 3
Total Amount
Procedure
• 1. Place the natural sponge in the container of water
• 2. Squeeze the water out of the natural sponge into the
beaker.
• 3. Record the amount of water in the beaker. Then pour the
water back into the container
• Repeat steps 1-3 for each trial.
• Repeat steps 1-3 using the synthetic sponge.
Sponge Lab Conclusions
1.Explain if your hypothesis was correct or incorrect.
2.What sponge type is better at absorbing?
3.What do you feel contributed to this outcome?
4.What are some errors you may have made in this activity?
Segmented
Worms
Phylum: Annelida
3 Major types of worms
1) Flatworms- are flat shaped and
primarily parasites. Ex. Tapeworms
2) Roundworms- found in moist areas and
can be parasitic. Ex. Hookworm
3) Segmented – most advanced of the
worms. Ex. Earthworms, leeches
Structures
• More then 17,000 species of segmented worms
• Have long tube-like bodies that are divided into segments or
“rings”
• Simplest organisms with a true nervous system and blood
contained in vessels
Resources
• A long digestive tube runs down
the length of the worm’s inside
body
• Worms take in dissolved oxygen
from the water through their skin
• Ex. earthworms, leeches
Movement/Responses
• Most segmented worms move by contracting and expanding their
muscles creating a wave of movement
•
•
Most segmented worms
respond to light by moving
away to an area of darkness.
Most will also move toward
an area of more moisture.
Reproduction
• Reproduction- depending on
the species they can reproduce
either sexually or asexually.
• Some worms have the ability to
regenerate their body parts.
Worm Lab
Focus Question- How do earthworms respond to light?
• How did the worm respond to
light?
• How did the worm respond to
different textures/surfaces?
Mollusks
Phylum mollusca
Mollusks
•There are three major classes
of mollusks:
1. Gastropods-snails and slugs
2. Bivalves-oysters and clams
3. Cephalopods-octopus
Structure
• Most have an outer shell, some
have an inner shell or have lost
their shell
• Mantle- tissue covering body
• Foot- contains a mouth or radula,
used for movement and
burrowing
Defenses
• Some can release “ink spray”
• Many use camouflage to hide
• Cephalopods have a very well
developed brain and can learn
Resources
Bivalves are
herbivorous filter
feeders and obtain
oxygen through gills
Gastropods are
herbivores and
absorb oxygen
through their skin
Cephalopods are
carnivores and
obtain oxygen
through gills
Movement/Responses to stimuli
Bivalves are mostly stationary
The bivalves have sensory
cells for discrimination of
touch and light.
Gastropods move by using their
foot attached to the stomach
They have nerve cells in the
tentacles, at the anterior end.
Some have eyes that are highly
developed.
Movement/Responses to stimuli
Cephalopods move by swimming or using jet propulsion
(pushing water out of their bodies to move rapidly through the
water)
They have well-developed brains, along with their highly
developed sensory systems and their lively, predatory behavior.
Cephalopods are considered the most
advanced of all invertebrates, and in
some cases are thought to be more
advanced than some vertebrates!
Reproduction
Reproduction:
• Most mollusks reproduce sexually.
• Some have external fertilization (bivalves and gastropods) while
others are mostly internal (cephalopods)
• Cephalopods have complex courtship and mating behaviors
including males fighting for access to the female for reproduction.
– Some cephalopod females even guard their eggs until after they are
born(octopus)
16 Echinoderms
Phylum: echinodermata
Structures
• Arms that extend from the middle
body outwards
• Have tube feet that take in oxygen
from the water and spines
• Ex. starfish, brittle stars, sea
cucumbers, sea urchins
Structures/Defenses
• Most echinoderms have an internal skeleton, or endoskeleton, made of
hard plates under the skin.
• Most species have radial symmetry and have body parts in multiples of 5.
• Defenses:
– Spines- sea urchin
– Toxins
– Loss of body parts
Resources
• Some species of echinoderms are filter feeders, such as the
sea cucumber
• Most species have small teeth that allow them to eat plant
material and animal matter.
Movement/ Responses to Stimuli
• Most echinoderms have a water vascular system (tubes of water)
that pumps water into tubed feet (suction cups) that they use for
movement.
• They have a simple nervous system with no brain
Reproduction
• Most species reproduce sexually
through external fertilization
• One species of sea star can reproduce
asexually by releasing an arm and a new
star can form from the severed arm
Draw and label this diagram
18 - Arthropods
Phylum Arthropoda
• Arthropods are the largest phylum in the animal kingdom with over
one million different species.
• The major groups of arthropods are:
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Crustaceans (shrimp, crab)
Arachnids (spiders, scorpions)
Centipedes and millipedes
Insects (grasshopper, butterfly)
Structures
• Have jointed legs
• Have hard outer coverings
(exoskeletons)
• Have segmented bodies
• Some have wings
• Open circulatory system
Resources
• Depending on the species they can
be herbivores, omnivores, or
carnivores.
• Obtain oxygen from the air through
gills or air tubes
Movement/ Responses to Stimuli
• Arthropods use jointed appendages to move.
They can walk, jump, swim or fly using these
jointed legs
• As they grow they shed or lose their
exoskeleton, this is called molting.
Reproduction
– Most species reproduce sexually
– Metamorphosis- a process in which an animal’s body undergoes a
dramatic change throughout its life cycle.
– In some species parents care for their young.
Defenses
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Hard exoskeleton for protection
Movement- running, jumping
Bad smells or tastes (stink bug)
Stingers (bees, wasps)
Camouflage – caterpillars
Poisons- Black widow spiders