Sponges, Cnidarians(jellies), Comb Jellies, Marine
worms, Portuguese Man O’ War, and many many
many many many more fun things…
…I just felt like typing many…many times…
Sponges are interesting organisms that can grow quite large.
Sponges are sedentary(attached/non moving), like a similar
organism called a Bryozoan. But, the also similar Rotifer, is
capable of movement… The animals found in all 3 of these
groups are multicellular, bottom-dwelling inverts.
The sponge has only a few specialized structures. 2 layers
of mostly undifferentiated cells; an inner layer called the
endoderm and and outer layer called the ectoderm.
Between the 2 layers there is a jellylike material called
mesenchyme. What a fun word huh…
Sponges are in the PHYLUM PORIFERA, meaning pore
bearing. Since they inhabit the seafloor-duh!, from the
intertidal zone down to the depths of the ocean, sponges
are considered BENTHIC, or bottom
Life functions of the Sponge
A sponges body has many holes or pores. Food particles
enter here at pores, called Ostia. Water and waste exit
through the large hole called the osculum, usually located at
or near the top. Inside the sponge are collar cells that
contain flagella, whiplike tail structures that beat back and
forth and aid in water circulation, and “food getting.”
Other cells called amebocytes are found in the
mesenchyme, also ingest and digest food. Digestion in the
sponge occurs within food vacuoles inside the individual
cells…similar to that of protozoa..it is intracellular.
More fun with a sponge…that kinda
Sponges aren’t exactly…responsive. Its not
going to run away if you touch it…I
know…shocker. It lacks a central nervous
system, so rapid reflex doesn’t occur. It does
have muscle like cells called myocytes, located
near the ostia and oscula. These can open and
close to allow water in or out. Most think this is
a defense mechanism.
Reproduction in the Sponge
Sponges reproduce with the typical egg and sperm set
up. Some will release eggs into the water as larvae,
some will disperse and settle to the seafloor to start a
generation. Individual sponges can be either male or
female, or can have both parts at any time…YES, I AM
SERIOUS. They are hermaphroditic, and can self
fertilize themselves. Sponges can also reproduce
asexually via a process called regeneration. If a piece of
a sponge breaks off, it can regrow into a whole new
sponge. Some other inverts do this…like most sea
Sponges are mainly marine. Although a FEW species
can be found in freshwater. Typically found in warm
habitats/tropical seas to cold polar waters. The bath
sponge (Euspongia), lives in trop. Waters and is very
common. Sponges have a commerical value to society,
but many are now being replaced with synthetic
sponges. It is estimated that a single Euspongia can
filter 100 liters of seawater in an hour. Sponges also
recycle minerals back into the water.
Sponges like the yellow boring sponge (Cliona) grow on
shells of clams and other shellfish. It uses an acid to bore
into holes in shells in order to attach to them. This sponge
also recycles calcium carbonate back into the water. Living
things, like sponges, that grow over the surfaces of
substrates are called encrusting organisms. Barnacles are
Some sea stars, snails, and fish eat sponges, particularly
young sponges. However, few animals overall eat sponges
because of their hard mineral matter, such as CaCO3 or
Silica. Sponges have a rigid structure and spines called
spicules. Some have elastic fibers called spongin. Sponges
come in a variety of shapes, sizes, and colors, as well as live
at various depths…Some sponges like the basket sponge,
grow large enough a person could sit inside them.
sponge. LEFT TOP
Cnidarians- “animals with stinging
Animals with stinging cells or stinging tentacles are
classified in the Phylum Cnidaria. Besides jellyfish and
corals, the Phylum Cnidaria includes sea anemones,
hydras, and other similar animals. There are more than
9,000 species in this Phylum, and they are divided into
3 classes- the Scyphozoa, Anthozoa, and Hydrozoa.
One of the worlds most toxic animals is in this Phylum.
It is the Box Jellyfish, found only in Australia. It is a
small, clear, extremely long tentacled jellyfish found off
Box jellyfish (sea wasp)
Members of this Phylum Cnidaria are characterized by
two cell layers, and a saclike digestive tract, tentacles,
which are long, flexible appendages, are arranged in a
ring around a central mouth, thereby giving these
animals radial symmetry.
A network of nerve cells and receptor cells make up the
nerve net, which is a simple nervous system. Impulses
do not travel along definite pathways. Instead, when
one part of the body is stimulated, the whole animal
Jellyfish are members of the Class Scyphozoa. All members of this
class have an umbrella shaped structure called a medusa, with tentacles
hanging down from it. The medusa is composed of two membranes,
the epidermis or outer membrane and the a gastrodermis, meaning
“stomach skin” or inner membrane. Lying between these two
membranes is the jellylike mass called the mesoglea. The lightweight
structure, shape, and thin ness of the jellies, as well as the material they
are made of allow them to float with ease. Jellyfish are typically
considered a zooplankton. They have limited locomotion (
movement) and are often found washed onto the shore/beaches.
Jellyfish carry out respiration by oxygen absorption diffusing thru the
thin tissue of their cells via the seawater. Waste gas, CO2 will diffuse
out in the opposite direction. The entire surface of the jelly does this
Diver and Lions Mane Jelly
Jellyfish feeding and defense…
Jellyfish use their tentacles for feeding and defense
mechanisms. The tentacles contain stinging cells called
cnidoblast. Inside each cnidoblast is a coiled threaded
barb called a nematocyst. This usually contains the
Nematocyst can discharge from either a chemical or
mechanical stimulus, and can also discharge even when
the organism is non living.
Food is digested in a saclike cavity with enzymes that
dissolve it. Waste products are egested, or expelled,
through the mouth. The medusa in many jellies is
sticky and can also catch food.
Jellyfish jellyfish jellyfish jellyfish…
Jellies have separate sexes and can produce both sexually
These look like colorful underwater flowers and are
members of the Class Anthozoa ( means “flower
animal”) They also posses stinging cells radial
symmetry and a nerve net…like jellyfish. UNLIKE
jellies though, these live as a Polyp, attached to a
substrate by means of a muscular foot. It is stationary
or sessile, and has limited movement. If you touch an
anemone, the animals responds by contracting and
closing up all of its tentacles and brings them inside of
its fleshy polyp.
Feeding/Defense in anemones…
Stinging cells are used to obtain food. Tiny organisms and small
fish are paralyzed by the discharging tentacles when they come in
contact with them.
Little shrimp and clownfish can often be found living unharmed
within the tentacles. This is because they have a protective
covering of mucus that protects them from being stung. Certain
clownfish will only associate with certain anemones. The shrimp
also serve to keep the anemone clean. Both the shrimp and
clownfish get protection and food from the anemone. This is a
mutual relationship called symbiosis. These “participants” are
referred to as symbionts.
Feeding occurs in the anemones mouth and digestion occurs
with enzymes after the stinging cells do their job. They engulf
their food completely surrounding it from the mouth and
bringing it in.
Reproduction is either sexual or asexual.
Coral reefs come in all shapes and sizes. Some are huge, like the
Great Barrier Reef in Australia, which is about 2,000 km long
and 80 km wide. However, the organism responsible for these
reefs is so small it might escape notice outside of its stony home.
They can only be seen through a microscope.
There are 2 types of coral- STONY (hard) and SOFT corals.
Stony corals are made of a hard limestone material like calcium
carbonate. These form massive structures and include corals like
the brain coral, staghorn coral, and star coral.
Soft corals are more flexible and are like a fibrous protein fiber.
They look similar to plants and sway in the water. Examples of
soft corals are the sea fan, sea whip, and sea plume.
The basic structure of the coral is the coral
polyp. The polyp resembles a small anemone.
Life activities such as ingestion, digestion,
sensitivity, exchange of gases, and reproduction
are similar in both anemones and coral polyps.
Coral is considered a COLONIAL animal- they
are attached to one another by a thin membrane.
The reef is a massive rock like structure composed
of CaCO3, which is built by stony coral polyps and
the organisms that live in them.
Living with the coral polyps are specialized cell
organisms that aid to absorb CO2. They are called
zooxanthellae. These are a type of dinoflagellate
that are captured by the coral polyp from the
marine environment. These aid in providing energy
in the form of glucose and sunlight to the coral, and
the coral provide a safe living spot for the
zooxanthellae algae. It is a symbiotic relationship.
Reefs are found in tropical areas around the world.
The water must be warm and have plenty of
sunlight. Corals are found in water shallow enough
for sunlight to penetrate, to provide warmth and
high energy amounts to the coral organisms.
Bleaching on corals can occur from to much UV
rays, as well as being broken in heavy storms,
waves, and even being run over by large
Sea Fans and Sea Whips
Hydroids and the
Portuguese Man-O- War (Man-of-War)
The Hydroid is a Cnidarian that closely resembles a
plant. These are members of the Class Hydrozoa.
They live in intertidal and subtidal zones.
Hydroids are actually colonial animals, made up of
many individual polyps that function together as a
single organism. The snail fur (Hydractinia) is a
hydroid colony who’s pink and reddish growth coats
the shells of many ocean animals like the hermit crab.
There is a hydroid that is not colonial, it is the
Tubularia, however, most hydroids do live a colonial
The Portuguese Man of War ( Man O’ War) is the
most feared of the hydroid colonies. It is not a true
jellyfish. It gets its name from the British sailors
during an 18th century war as an insult to a crew of
Portuguese Soldiers. The man of war (PHYSALIA)
is a hydrozoan because it is a colony made up of
different types of polyps. It has a set of long
tentacles with powerful nematocyst. The sting of
the PMOW is very strong and powerful. Many
people become ill from the sting. Death does or can
occur in rare instances.
More Port. MOW
The different polyps that make up Physalia are
adapted for a variety of functions. One kind of
polyp makes up the gas filled float or bag that keeps
the colony afloat. The “float” resembles that of a
sail. Another type of polyp makes up the stinging
tentacles, which can be several meters long. And
again, another type of polyp makes up the digestive
These are often found on shore, washed up because
of their inability to move against currents and the
“sail” often directs them towards the shore.
INTERESTING REEF OCTOPUS…not
related here…showing you..
1) Compare one of the body systems of a sponge with
that of a human. (think of one!!!!) Describe how they
are similar and/or different.
2) Describe AND Draw how a sponge filter feeds.
Include the labeled “parts” of the sponge.
3) Define ostia and osculum and explain how they
4) Explain one way that sponge larvae are more animal
like than adult sponges. THINK!!! ( it is NOT a
“notes” answer…THINK THINK THINK!)
The boat debate:
Doctor Girl- 6 yr old
Engineer Father of boy
Judge Mother of boy
Police officer Child in wheelchair
Fireman Adult Entertainer
Priest (any religion) You
Boy- 6 yr old Captain
Pro- Athlete Mechanic
______ are in the Phylum Porifera. There are about ___ different species and
most of these are _______organisms found in oceans and seas. A few sponges
are found in the ______ zone, but these are small and not brightly colored.
Sponges are _______ that trap ______ from water as it flows through them.
Sponges have no basic body arrangement and are said to be _________.
Sponges live attached to one spot as adults so they are ______. The skeleton
of sponges is made of a flexible protein called _______ and hard fibers called
______ which are composed of Calcium carbonate (CaCO3) or silicon dioxide.
Sponges are full of holes called _____ through which water flows into their
______ bodies. Sponges are the simplest animals and lack the ______ level of
specialization like all other animals. Sponges do have some specialized
_______in their bodies. Special cells called _________ line the pores and have
_________ that spin to pull in water. ______cells at the base of the
choanocytes capture plankton from the water and start digesting it. ________
are special cells that carry this food to all other parts of the sponge. Waste and
excess water leave a sponge through a large opening at the top called the
________. Sponges reproduce asexually also and are __________, producing
both eggs and sperm.