Day 6 Body Cavities and Porifera
Diploblastic organization
-Diploblastic tissue organization is the simplest type of tissue organization
-There is basically only two tissue levels in a diploblastic animal
-The two layers are the
-Ectoderm
-Endoderm
-In between these two layers is a Mesoglea which sometimes has cells and sometimes does not
-The ectoderm gives rise to the epidermis and the endoderm gives rise to the gastrodermis
Sea Jellies are an example of a diploblastic animal
Triploblastic Organization
-Triploblastic organisms have an extra tissue layer called a Mesoderm
-The mesoderm gives rise to the organs
Coelom
-A coelom is the space between the mesoderm and the gut
-This space is where the organs rest
There are three types of animals with coeloms
-Acoelomate
-Psudocoelomate
-Coelomate
Invertebrates
-97% of all species of animal on the planet are invertebrates
-Almost all invertebrates have a marine representative
-If it was not for the insects we would be able to say that the majority of animals are marine!
Now lets start talking about our 9 phyla of animals!
Phylum Porifera (Sponges) 5,000+ Species
Porifera Characteristics
-The name Proifera translates as Pore Bearers
-The phyla Porifera are the sea sponges
Sea Sponges are:
-Benthic - Live on the bottom of the sea
-Sessile - Stuck to the bottom
-Suspension Feeders - eat whats floating in the water
-Filter Feeders - filter the water
-Mostly Hermaphrodites - the make both sperm and egg
-Broadcast spawning - Release sperm and eggs into the water where they fertilize on their own
-Planktonic Larva - The larva float around in the water until they land somewhere and grow
-Porifera Body structure
-Asymmetrical - No symmetry
-Have three cell types
-Pinacocytes
-Mesenchyme cells
-Choanocytes
-They have a central cavity
-They have no tissue or organs
-Sponges have a rough skeleton made of silica spicules
-There are some sponges however that have a soft calcium based spicule skeleton
-This group is in the Genus Spongia
-The sponges in the Genus Spongia are the ones that humans use as cleaning sponges
-They were also used for many other things like, helmet padding, contraceptive, and painting
-Sponges are one of the oldest animals still extant (not extinct)
-They lived almost 500 million years ago
-They are the simplest animal
-They have no real muscles
-No brain
-No nervous system
-It is hypothesized that they evolved from a colony of single celled protists similar to the choanoflagellida
-A sponge's choanocytes strongly resemble the choanoflagellida
-Sponges use their choanocytes (collar cells) to filter water
-The collar cells move their flagella pumping water through the sponge
-The sponge's cells feed on any particles that were in the water
-Sea sponges are important to the ocean ecosystem because they filter and clean the water
-Sea sponges also have amoebocytes
-Cells that can move through the body of the sponge
Watch this video on the phyla porifera. Create a box in your sketchbook, title it "The Phylum Porifera" and take notes, write down interesting things that you learn from the video and include an image in your sketchbook. Make sure you understand the characteristics of a sea sponge and what a sea sponge is.
There are three classes of Porifera
-Class Calcarea
-This class has spicules composed of calcium
-Class Hexactinellida
-This class has spicules composed of silica
-Six rayed
-Lattice, cup, or vase shape
-Class Demospongiae
-Brilliantly colored
-needle shaped or four rayed spicules
-Some are made of silica and some spongin
Sponges come in many shapes
There are tube sponges
Yellow Tube Sponge
Barrel Sponges
Giant Barrel Sponge
Vase Sponges
Pink Vase Sponge
Rope Sponges
Encrusting Sponges
Watch this SciShow video on sea sponges. Create a box or section in your sketchbook and title it "Carnivorous Sponges". Take notes, write down anything interesting that you have learned.