Download Porifera and Cnidaria Student Guided Notes

Porifera and Cnidaria Student Guided Notes
Characteristics of Animals
There are approximately ___________________________ recognized by zoologists.
We are going to spend the remainder of the course looking at the most common animal phyla.
We will start with the simplest phyla and work our way to the most complex. Below is a list of
animals you will learn more about.
Porifera
Cnidaria Platyhelmin Nematoda Annelida
thes flat
Roundwor Segmented
worms
ms
Worms
Sponges
Planarians
Sea
anemone
10,000
known
species
Coral
Flukes
Calcareous, Jellyfish Tapeworms
glass,
coralline
(tropical),
demospong
es (like the
bath
sponge)
Hydra
Ascaris
Mollusca
Arthropoda
Oligochaeta Bivalves: Spiders
:
clams,
Earthworms oysters,
mussels
Hirudinea:
Leeches
Echinod Vertebrat
erms
es Chordata
Sea
urchin
Gastropo Crustaceans Sand
ds: Snails, (crab, lobster) dollars
nudibranc
hs
Polychaeta: Chitons
Cephalop
ods:
Squid,
Octopus
Insects
Sea star
Sea
cucumbe
r
How did Animals Evolve?
Today it is thought that...
The earliest animal probably _________________________________________
___________________________________________ (700 mya)
Hypothesis: ______________________________________________________
_____________________ and the early animals populated seas, fresh waters, and
eventually land
Use the following table to help make comparisons as you move through the rest of the course:
Characteristics of Animals
Animals are __________________________________________________________
______________________________________. Animals can be large, have a stable
controlled internal environment and ______________________________________. Animals
have two unique types of tissues: ____________________________ for impulse conduction
and _____________________________________ for movement (Tissue: several cells
working together to do a job)(Organ: made up of several different tissues). As we go through
this part of the course look for development of sensory organs and coordination of systems.
Animals are Multicellular and Heterotrophic
What does it mean to be multicellular?
- ____________________________________.
- usually have different cell types.
- ____________________________________
_____________________________________
that benefits the whole animal.
- cells work together by forming tissues (____
____________________________________
____________________________________).
- ____________________________________
___________________________________
(group of different types of cells working together
to perform a common function - ex. heart is
formed of muscle and nerve tissue working
together).
Having many cells allows ________________
_____________________________________.
Because of cell specialization the animal can be
large. They can also move. This size allow
stabilization of the animals internal environment
and relative independence from a harsh
environment.
What does it mean to be heterotrophic?
Heterotrophs must ingest other organisms or organic material that is decomposing.
___________________________________________________________________________
_______________________________________________. This is the opposite of autotrophic
organisms that make their own organic molecule.
Animal Development
___________________________________________________________________________
__________________________________________________________________. In most
species, small flagellated sperm fertilizes larger non-motile eggs. The zygote goes through
mitotic cell divisions and ____________
________________________________
________________________________
________________________________.
During gastrulation,
________________________________
________________________________
_______________________________(a
small dent). ____________________
_____________________. The ___________________ as the inner layer and the
________________ as the outer layer.
After gastrulation there are two
patterns of development:
1. ____________________
- the blastopore develops into
the _____________.
2. ____________________
- the blastopore develops into
the ______________.
Classifying Animals
****This is very important*****
As you learn about the various phylum you will be asked to compare them based on
these criteria.
Animals, being such a diverse kingdom, are classified into phyla based on a variety of
characteristics. Those characteristics include: ________________________________
______________________________________________________________________
_____________________________________________________.
Level of Organization, Body Cavity, and Body Plan
Levels of organization from simplest to most complex is ______________________________
____________________________________. Although many animals have the highest level
of organization, ___________________________, some are only organized at the
__________________________. This means that __________________________________.
Those that do have tissues can be distinguished from those with organs _________________
__________________________________________________. If an animal develops with
___________________________________________________________________________
__________________________________. If an organism has ________________________
__________________________________________________________________________.
_________________________________________. Not all animals have all ______________
__________________________________________________________________________.
1. __________________________________________ body plan is a blind sac or ______________________.
With this type of body plan food goes in the same
opening waste comes out of. Examples of acoelomates
are Cnidarians (ex. Jellyfish) and Platyhelminthes
(flatworms).
2. __________________________________________
- body plan is a _______________________________.
A tube-within-a-tube has a separate digestive system
(inside tube) surrounded by the body (outside tube).
This allows for more specialization of tissues as
different sections of the tube develop to perform
different roles. _______________________________
___________________________________________.
An example of a pseudocoelomates are ____________
_________________________________.
3. _____________________________________
or body cavity - body plan is a _______________
_________________________________, but
_______________________________________
_______________________. These organisms
often have ______________________________
__________________________. Coelomates
include _________________________________
_____________________________________, Mollusca (mollusks), Echinodermata (ex. sea
star)
Organization Practice Exercises
Types of Symmetry and Segmentation
Symmetry describes __________________________________________________________
Animals can be asymmetrical, radially symmetrical, or
bilaterally symmetrical.
__________________________________________
__________________________________________.
No matter how you slice it both sides will be of a
different shape. These animals are often sessile or
non-motile.
__________________________________________
____________________________________________________________. These animals
can be compared to round objects such as bowls, tires, or wheels. These animals are often,
but not always sedentary.
___________________________________________________________________________
____________________. They can only be cut one way to produce two equal halves. These
animals are ____________________________________________________________. The
word cephalization comes from the root word cephalon which _________________. Although
not all animals with cephalization have a distinct head, they will have ___________________
_____________________________________. This nervous tissue is found only in animals.
___________________________________________________________________________
____________________________________________________.
The _____________________________________________ is referred to as segmentation.
This ____________________________________________________________ as different
segments can specialize for different roles.
Porifera
Introduction to Sponges
"... the subject is actually repulsive in its difficulties''
- Carter (1875) on the study of sponges
Phylum Porifera
The simplicity of this group led to the frustration of scientists such as
Carter for many years. Being ____________________________
and __________________________________________________
are __________________________________________________
_________________________. For these reasons they were often
classified as plants. However, upon examination of their _____________________________
_________________________________it was determined that _______________________
___________________________.
The term ________________________________________.
The "pore bearers" are the sponges and are thought to be
one of the oldest multicellular species. Fossils of sponge
spicules have been found in the precambrian era rock layers
dating to 600 million years ago.
It is the sponges with a spongin skeleton that are dried and used
commercially. The skeleton of these animals was used as a washing
sponge before synthetic sponges became common. They can still
sometimes be purchased as a "sea sponge" for sponge painting or you
may find that the sponge that you have been bathing with is really an
animal. Did you know that the bath sponge actually received its name
from the animal and not the other way around.
The are about 9000 different species of Sponges.
SIZE
Sponges range in size from as small as 0.5 cm tall to as large as 2 meters tall.
HABITAT
mostly warm marine waters ____________________________________________________
do exist. example: Grantia
Characteristics of Sponges
BODY ORGANIZATION
Sponges have _______________________________________ because they have no true
mesoderm. ________________________________________________________________.
In addition, they _____________________________________________________________
__________________________________________________________________________. .
Sponges have many pores on their surface that are both _____________________________
______________________________________.
These multicellular sponges ____________________________________.
1. Endoderm – inside skin.
2. Ectoderm – outside skin, protective.
The “middle area” contains ______________________________
____________________________________.
______________________________________ in the middle
layer _______________________________________________
___________________ (hence the name). _________________
____________________________________________________
______________________________________________________________. They also carry
oxygen to other cells, dispose of waste products, and maintain the structure of the sponge.
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________.
MOVEMENT
The _________________________________ (moving) and can swim. The _______________
______________________ (non-moving). Adults are attached to substrate such as rocks.
Classes of Sponges
Demospongea – _______ Hexactinellida – ___________
______________________ __________________________
_____________________. __________________________
_________________________
Glass sponges - hexactinellids.
Calcarea - _______________
_________________________
_________________________
____________
Sponge Reefs were thought to be abundant during the Jurassic period 200 million years ago.
These reefs were thought to be extinct until 4 reefs
were found in the early 1990s. Sponge reefs are
restricted to temperate
Pacific coastal waters.
Such reefs exist in
Hecate Strait and
Queen Charlotte
Sound.
Feeding in Sponges
A sponge that is 10cm tall must filter more
then 100L of water a day to stay alive!!
In feeding, __________________________
___________________________________
___________________________________
___________________________________
______________________. The sponge is a
_____________________ and ___________
____________________________________
___________________________________.
The food particles are then either digested by the collar cell or passed to an amoeboid-like cell
for digestion and circulation.
Review of Feeding in Sponges
Not a true digestive system.
_______________________ – food enters with water.
Water enters via tiny pores (ostia) = incurrent.
Water exits via massive pore (osculum) = excurrent.
Collar cells (choanocytes) engulf and digest food.
Reproduction in Sponges
Both _________________________________________________________ occur in
sponges. _________________________________________________________________
_______________. In _____________________________, a piece breaks off and forms a
separate animal. In __________________, the animal reproduces by growing a second
sponge from the side of the parent that eventually detaches. During sexual reproduction, an
egg and sperm combine to form a flagellated zygote which can swim to a new location.
REPRODUCTIVE SYSTEM – not a true system.
Again we see sperm and eggs are specialized cells.
Sponges are monoecious meaning a sponge can make both egg and sperm.
Other Systems in Sponges
RESPIRATORY SYSTEM – not a true system
- _____________________________________
__________________________________ (O2
diffuses into and CO2 out of cells).
-water enters via tiny pores (ostia) = incurrent
-water exits via massive pore (osculum) =
excurrent
CIRCULATORY SYSTEM – not a true system
-specialized cells = _______________________
__________________________________ to
other cells in the sponge.
EXCRETORY SYSTEM – not a true system
-specialized cells = ___________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________.
-Water enter via ostia = incurrent.
-Water exits via osculum = excurrent.
NERVOUS SYSTEM – NONE
MUSCULAR SYSTEM – NONE
SKELETAL SYSTEM – NONE
Economic Importance
Sponges are used for ________________
(spicules of spongin). They have the ability to hold large amounts of water. Sponges have now
been replaced with synthetic materials for cleaning.
Natural sponges are still harvested from the Gulf of Mexico. ___________________________
___________________________________________________________________________.
Cnidaria
Introduction to Cnideria
Phylum Cnidaria includes animals such as _________________________________________
___________________________.
Cnidae refers to the creatures’ “_____________________________” and they are commonly
called "sea nettles". Nettles are a stinging plant.
Cnidarians are further up the “evolution ladder” meaning _____________________________
__________________________________ (sponges).
There is estimated to be approximately 10 000 species of
Cnidarians.
The habitat for most cnidarians is ___________________
(marine = salt water) but some species live in _________
___________.
______________________________________________
_______________________________________. The
medusa form (bell-shaped) __________________ (moving)
while the _______________________________
_______________________________ (non-moving). Some
cnidarians exist in both forms throughout their life cycle
showing an ________________________________
___________________________________________________________________________
The size of cnidarians ranges from as small as a 0.5 cm tall bell up to a 2.4 m diameter with
tentacles ranging upwards of 50 meters.
FACT: Cnidarians have a single external opening that serves as both the mouth and the anus!
Characteristics of Cnidarians
Cnidarians are a _______________________________ animal. They can be ____________
______________________ and some species will have life cycle stages of each.
They have an _______________________________________________________________
__________________________________________________________________. These
_____________________________ lead to a tissue level of organization. _______________
_____________________________________________________________. The
gastrodermis surrounds the center of the body which is called the ______________________
____________________________________________________________. That is, food
enters the same opening that waste is excreted through. Tentacles are arranged to surround
the mouth.
___________________________________________________________________________
__________________
are examples of polyps.
The difference being that
corals have a calcium
carbonate skeleton while
sea anemones _______
____________________
____________________
____________________
____________________
____________________
____________________
Stinging Cells
For capturing prey and for defence _______________________________________________
___________________________________________________________________________
_____________________________ which contains a coiled hollow thread. These
nematocysts are triggered to discharge by direct contact or other external stimulus. The thread
will uncoil when the cnidarian is touched and spear the prey or predator. The spines help
anchor the stinging thread into the prey.
In some species these threads _______________________
________________________________________________
________________________________________________
________________. This is why handling jellyfish can cause
the skin to numb or in more severe cases cause muscle
paralysis and heart failure. In some areas of the globe large
numbers of jellyfish cause beach closures. The sting of a
Box jellyfish may cause death in as little as 3 to 20 minutes.
Classes of Cnidarians: There are four Classes of Cnidarians;
Class Hydrozoa: Examples are Hydroids.
Class Scyphozoa: Example is the Floppy jellyfish.
Class Cubozoa: Examples are the Box jellyfish.
Class Anthozoa: Examples are Sea anemones and Corals.
Class Hydrozoa
This class of cnidarian
includes approxiamtely
3,700 species. Most live in
colonial organizations in
the oceans.
Example: Physalia –
_____________________
_____________. Its gas
filled float keeps the colony
at the surface of ocean.
Tentacles can be up to
20m long and the
nematocysts poison can be
fatal.
Colonialism in Hydroids
Hydroids live in finely-branched
colonies. Individual hydroid polyps
are connected to each other by
their gastrovascular cavity. There
are different kinds of polyps in the
colony. Gastrozooid feeding
polyps have many tentacles for
catching plankton. Dactylozooid
defense polyps use nematocysts
to catch prey or deter predators.
Gonozooid reproductive polyps
produce medusoids (tiny jellyfish
like structures). Ex. ___________
___________________________
__________________________
_____________ exist only as
polyps and are not colonial.
They live in fresh water such
as quiet ponds, lakes, and
streams. Hydra range from 1-4
cm in length and are white or
brown in color. They attach
themselves to rocks or water
plants by means of a sticky
secretion produced by cells in
the hydra’s base. __________
________________________
________________________
________________________
________________________
_____ when low temperatures
trigger the development of
eggs and sperm.
Draw one here:
More on the Hydra
As previously stated, __________________________________________________________
____________________________ in most lakes and ponds. __________________________
___________________________________________________________________________
___________________________________________________________________________
__________________________________________________________________. During
development the endoderm and ectoderm produce different tissues. ____________________
___________________________________________________________________________
________________________________________________________. Tentacles are used for
prey capture and are controlled by muscle fibres and a _______________________________
___________________________________________________________________________.
Hydra ____________________
_____________________ by
producing testis or ovaries in the
body wall, but do not enter a life
cycle with a medusa. Instead,
the sperm and egg will combine
and grow to form a polyp.
_________________________
_________________________
_________________________
_________________________
_________________________.
Label the Hydra
Label the Hydra
Class Scyphozoa
This class of Cnidarians are referred to as
"cup" animals. This shape describes the
________________ form. There are more
then 200 species known commonly as
jellyfish. They can have tentacles up to 7m
long. _____________________________
___________________________________________________________________________.
Life cycle of a Jellyfish (Aurelia)
To reproduce the _______________________
_____________________________________
_____________________________________
____________________________________.
A zygote is formed followed by a blastula
which leads to a planula (ciliated larva) and
finally a new polyp.
Class Anthozoa
The term Anthozoa means
“___________________________________”. There
are approximately 6,100 marine species.
Examples are
_______________________......................._______
_________________________________________
_____________________________. When they die
their hardened skeletons remain and over time build
up into ____________________________. Coral
reefs are restricted within 30 degrees north or south of the equator as they require sunlight.
Corals get the majority of there food energy from photosynthetic algae.
Phylum Ctenophora
There are approximately 100 species of Ctenophora. The
term “_____________________________” refers to the
_____________________________________________
that run along the outside. Unlike jelly fish ____________
______________________________________________.
They are the largest organism to move this way. Ctenophora
resemble jellyfish and are called _____________________.
Comb jellies have _______________________. They
_______________________________________________
_______________________________________________
_______________________________. Colloblasts are
normally located on 2 tentacles. They also _____________
_______________________________________________
________________________________________________________. The most striking of
these species are bio-luminescent so can produce light.
Cnidarian Body Systems
DIGESTIVE SYSTEM – not a true system.
-Food enters gastrovascular cavity via mouth.
-Extracellular digestion (enzymes secreted into cavity).
-Cells lining the cavity absorb digested nutrient and smaller food particles.
The relationship between structure and function is clearly seen in the way cnidarians feed. The
tentacles capture small animals with their nematocysts and paralyze them by injecting poison.
The tentacles then push the prey into their gastrovascular cavity through the mouth. Once in
the mouth enzymes found here break up the prey and the cells lining the cavity absorb the
nutrients.
CIRCULATORY SYSTEM – not a true system.
-Nutrients and gasses _____________________ directly across the thin cell layers.
RESPIRATORY SYSTEM – not a true system.
-Gas exchange directly between cells and water by _________________ (O2 diffuses into and
CO2 out of cells) both across epidermis and gastrovascular tissues.
EXCRETORY SYSTEM – not a true
system.
-Waste diffuses from cells into
gastrovascular cavity and is then released
through the mouth.
MUSCULAR SYSTEM – NONE.
-No muscle cells but some cells can
contract and relax (e.g. in the tentacles).
SKELETAL SYSTEM – NONE.
NERVOUS SYSTEM – a basic system.
-A ______________________________
____________________ that react to
presence of food and danger for the
purposes of feeding and protection.
REPRODUCTIVE SYSTEM
Many cnidarians alternate between ____________________________________ forms in their
life cycle. ___________________________________________________________________.