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 Platyhelminthes flat worms

Nematoda Roundwor

ms

Annelida Segmented

Worms

Mollusca Arthropoda Echinoderms

Vertebrates -

Chordata

Sponges Sea anemone

Planarians Ascaris Oligochaeta: Earthworms

Bivalves: clams, oysters, mussels

Spiders Sea urchin

10,000 known species

Coral Flukes Hirudinea: Leeches

Gastropods: Snails, nudibranchs

Crustaceans (crab, lobster)

Sand dollars

Calcareous, glass, coralline (tropical), demosponges (like the bath sponge)

Jellyfish Tapeworms Polychaeta: Chitons Insects Sea star

Hydra Cephalopods: Squid, Octopus

Sea cucumber

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. ___________________________________________________________________.