Sponges and Cnidarians

Report

Phylum = Porifera
› Scientific name = Calcareous sponge
 Common Name = Yellow Calcareous Sponge

Phylum = Porifera
› Scientific name = Spongia officinalis
 Common Name = Bath Sponge

Phylum = Cnidaria
› Scientific name = Physalia utriculus
 Common Name = Bluebottle

Phylum = Cnidoria
› Scientific name = Octocorallia alcyonacea
 Common Names = Red Sea Soft Coral
Sponges were one of the first animals living on
Earth, dating back 730 million years ago.
 Most are marine (9,000+ species)
 They share some characteristics with living animals
today.
 Sponges are multicellular but are thought to have
evolved from unicellular protists.

› Multicellularity
 If they are put through a fine mesh, they separate and then
come back together to form a new sponge.


Various shapes, sizes, habitats, and colors
Sponges date back to the Precambrian era
One of the first animals fossils that were
recognized were cnidarians
 The first cnidarians were composed of
soft tissue
 The earliest Cnidarian fossil discovered is
580 million years of age


Sponges
› Asymmetrical
 They lack symmetry
› Acoelomate
 Do NOT have a body cavity
› Can also have radial symmetry
Pic from- http://cache.eb.com/eb/image?id=72139&rendTypeId=35
Vocabulary
 Sessile

›

Choanocytes
›

Flagellated cells that are found on the interior of the sponge
Ostia
›

Firmly attaching to surfaces and not moving
pores
Osculum
›
The opening at the top of a sponge
http://www.marinefoundation.org/sponge2.gif

Has radial symmetry
A body plan that can be divided into similar halves by
passing a plane at any along a central axis
›
http://www.uic.edu/classes/bios/bios100/labs/radial.jpg
(this website is for the works cited for this radial symmetry pic)


Cnidarians have two tissue layers
› Outer- epidermis
› Inner- gastrodermis
 In the center of the body is that gastrovascular cavity
 a hollow gut
Vocabulary
 Medusa

Bell-Shaped
› Specialized for
swimming
›

Polyp
Vase-Shaped
› Specialized a sessile
existence
 sessile existence
›
 Being able to attach
firmly to a surface and
not move

Some sponges are supported by spongin
›

Flexible protein fibers acting as a skeleton for support
Other sponges are supported by spicules
›
Small-needlelike made of silicate (silicon dioxide) or calcium carbonate

The structural support in Cnidarians is
Mesoglea
› Jelly like substance provides structural
support in water


Sessile, do not have the ability to pursue food
Filter Feed
› Choanocytes beat flagellum, pumping water in through
the ostia, pores
› Sponges filter the food out of the water
› Choanocytes trap the food in their small hair-like
projections
› Water leaves through osculum or mouth
Water/food IN
through ostia
Water-OUT
through osculum

Cnidocysts capture prey
› Tentacles are used to capture food
› Trigger triggers the nematocyst to be
expelled
 The nematocysts sting the prey the spine and
trap food with the fillaments
› Trap food with mucous found at mouth and
tentacles
Transportation:
 During the premature stage

› The larva moves by means of flagella until
they find a place to attach to and thus
begin their sessile stage

Sessile
› During adulthood

Circulation:
› A sponge has water flow in through its ostia
and go out through its osculum

Many adult cnidarians are free-floating
› In the larval stage, they are free swimmers
 Larval stage- part of the life cycle of a
cnidarian
http://universe-review.ca/I10-82-cnidaria.jpg

No specialized systems found in
cnidarians that aid in circulation
› Circulation mainly achieved through
diffusion

Does not have a respiratory system
› Takes in water (H2O) through its pores
 They have canals that move the water
throughout the sponge

Goes through diffusion
› There small body size allows oxygen to
diffuse from water through their thick
membrane
 No respiratory structures are needed
 Lungs, gills, etc.
Sponges beat the flagella of certain cells
to pump water in and out of its osculum
 Sponges have carbon dioxide and other
wastes removed quite easily

› The water moves it in and out through the
pores
Maintain water balance by osmosis
 Diffuse water through their tissue


Sponges reproduce both asexually and
sexually
› Asexual reproduction- Budding internally and
externally
› The new sponges are similar to their parents

Reproduce both asexually and sexually
› Asexually- budding or binary fission
 Binary fission- splitting a parent cell into two
equal parts
› Sexually- an asexual cnidarian reproduces
 Produces an organism that can reproduce
sexually
 This leads to the variation in generations

Sponges do not have a nervous system
› Lack sensory cells and nerve cells

Contains a nerve net
› Has a network of nerve fibers
 Able to communicate when overlapped

Not cephalized

The largest sponge ever measured was a
Monoraphus sponge
› It was ten feet wide!!
In the Caribbean Sea, sponges can filter
all of the water in one day!!
 Within a sponge, it is possible to find
16,000 other animals!


Over 10,000 species
› 130 of those species recorded in Sydney
Harbor
Group name Cnidarian comes from the
word nettle
 The body of the a Cnidarian is a sack
with an opening, such as a medusa or a
polyp

"http://cache.eb.com/eb/image?id=72139&rendTypeId=35."
Marriam-Webster. 2006. 7 Apr 2009
http://www.nps.gov/history/museum/exhibits/dino/geotime/
geo_time_graphic.gif." 7 Apr 2009
Bird, Jonathan.
"http://www.marinefoundation.org/sponge2.gif ." 7 Apr
2009
"http://universe-review.ca/I10-82-cnidaria.jpg ." 7 Apr 2009
Postlethwait, John, and Janet Hopson. Modern Biology.
Austin: A Harcourt Education Company, 2006.
"iod.ucsd.edu/~amanda/Files/lab5InvertsI.ppt." 7 Apr 2009
ERA PICK IS FROM
 http://www.nps.gov/history/museum/exh
ibits/dino/geotime/geo_time_graphic.gif


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