Transcript Cnidaria - Raleigh Charter High School

Ctenophora
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“Tortugas Red” (still
unnamed)
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Gastrovascular cavity: canal
system and one or more anal
pores
No coelom
Germ layers: ectoderm and
endoderm (with mesoglea in
between- this is up for debate)
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Biradial symmetry
Tentacles with colloblasts (discharge
sticky filament)
Uses comb plates, or plates of cilia,
for mobility (unique)
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Mesoglea is a jelly like
substance that makes up most
of the organism and forms
structural support
Digestion is extracellular.
Breakdown products are
distributed via branches of the
gastrovascular cavity.
Undigested food is expelled
through mouth and anuses.
Digestive system includes a
“pharynx” of folded
epidermis.
Sexual, external reproduction
(although has great
regeneration powers) – mostly
hermaphrodites
Lack the polyp-medusa life
cycle found in Cnidaria
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Most have no nematocysts
Lack the polyp-medusa life
cycle found in Cnidaria
Lack cnidocytes found in
Cnidaria
Nerve net: form nerve-like
strands beneath the comb
cells
Unique structure: statocysts.
Used for balance and
movement (much like a
flagellum) – serves as the
body’s main sense organ
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Pleurobranchia (sea
goosebery)
Beroe
•Bathocyroe fosteri
•Larva of
Bolinopsis
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In a few species, special cilia in the mouth are
used for biting gelatinous prey.
The opening of the mouth is able to seal up like
a zip-loc bag once the prey is inside.
Ctenophores can live in depths of up to 4 km!
“Ctenophore” in Greek means “comb-bearer”
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Movie of Beroe Ctenophore
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Radial Symmetry
Two germ layers
(ectoderm and
endoderm)
No Coelom
Blastopore does not go
all the way through and
it has no anus
The Gastrovascular
cavity is also called the
coelenteron
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Movement is
coordinated by a simple
network of nerves
Have Tentacles that get
the food to their central
mouth
They use jet propulsion
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Cnidarians reproduce both sexually and asexually.
They reproduce asexually by budding. The bud will
eventually fall off the parent organism and becomes a
new polyp. Some cnidarians reproduce sexually by
releasing egg and sperm into the water. They (the eggs)
will be fertilized by sperm and develop into a larva
called planula. The planula will then develop into a
new polyp which will produce new medusas called
ephyra. Medusa body types of cnidarians have both a
sexual and asexual stage. The stages alternate. Medusa
reproduce sexually to produce polyps, which will grow
up and reproduce new medusa.
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Has an outer wall, epidermis, specialized and
complex
Contains Sensory cells and nematocysts (also called
cnidocytes) that are defense
 Inside is the mesoglea which is a jellylike substance
that supports the jellyfish
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The Bluebottle or Portuguese Man-of-War is not a
single animal but a colony of four kinds of highly
modified individuals (polyps). The polyps are
dependent on one another for survival.
The float (pneumatophore) is a single individual
and supports the rest of the colony. The tentacles
(dactylozooids) are polyps concerned with the
detection and capture of food and convey their
prey to the digestive polyps (gastrozooids).
Reproduction is carried out by the gonozooids,
another type of polyp.
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Grow in low nutrient waters
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High nutrients encourage the growth of algae which
harms reef
Many individual coral organisms that secrete
calcium carbonate which is the hard structure
that makes up the reef
A coral reef supports many different life forms
Anthoazo
Hydrozoa
Scyphozoa
Conulata
Cubozoa
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Sponges can be either radially
symmetrical or asymmetrical
• Sponges have three different body plans
* Asconoid sponges are shaped like a simple tube perforated by pores. The open internal part of the
tube is called the spongocoel; it contains the collar cells.
* Syconoid sponges tend to be larger than asconoids and have a tubular body with a single osculum.
The synconoid body wall is thicker and the pores that penetrate it are longer, forming a system of simple canals.
These canals are lined by collar cells, the flagellae of which move water from the outside, into the spongocoel and
out the osculum.
*The third category of body organization is leuconoid. These are the largest and most complex
sponges. These sponges are made up of masses of tissue penetrated by numerous canals.
Porifera
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Water movement is driven by the beating of flagellae, which are located
on specialized cells called choanocytes (collar cells)
Adult sponges are generally assumed to be completely sessile, but a few
studies have shown that adult sponges in a variety of species can crawl
slowly.
Reproduction by sponges is by both sexual and asexual means. Asexual
reproduction is by means of external buds. Sexual reproduction takes
place in the mesohyl. Male gametes are released into the water by a
sponge and taken into the pore systems of its neighbors in the same way
as food items. Spermatozoa are "captured" by collar cells, which then lose
their collars and transform into specialized, amoeba-like cells that carry
the spermatozoa to the eggs. Some sponges are monoecious; others are
dioecious. In most sponges for which developmental patterns are known,
the fertilized egg develops into a blastula, which is released into the water.
The larvae may settle directly and transform into adult sponges, or they
may be planktonic for a time.
A spongocoel is a large central cavity of sponges. Water enters into the
spongocoel through hundreds of tiny pores (Ostia) and exits through the larger
opening (osculum).
Porifera Anatomy
Stove Pipe Sponge
Hard Coral
Purple Tube Sponge
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Poriferans don't have mouths; instead, they have tiny
pores in their outer walls through which water is
drawn.
Water flowing through sponges provides food and
oxygen, as well as a means for waste removal.
Many times of poisonous porifera have been found in
oceans
In 1997, use of sponges as a tool was described in
Bottlenose Dolphins in Shark Bay. A dolphin will
attach a marine sponge to its nose, which is
presumably then used to protect it when searching for
food in the sandy, and sometimes rough sea bottom.
Porifera are also used by cosmetic companies to make
lufas and bath sponges
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What is a spongocoel?
Explain briefly how a sponge reproduces
What kind of symmetry do sponges have?
Describe two types of sponges
What Group has biradial symmetry?
What Group includes the Portuguese Man of
War?
Which group has cilia in their mouth to bite
gelatinous prey