Sponges and Cnidaria and Cnetophora Flashcards
What Phylum are sponges a part of?
Porifera meaning “pore bearers”
Do sponges have true tissues?
No. They have no nervous system or muscles. They have a loose aggregation of cells.
What environments do sponges live in?
Mostly marine and all aquatic
How do Sponges feed?
Filter feed through many pores and canals
What cells pump water in sponges?
Collar Cells (Choanocytes) pump water
What is the sponge made of?
Skeleton made of spicules and spongin
Do sponges move?
No. They are sessile but have motile larvae.
How has the sponge body plan evolved over time?
To enhance filtration efficiency with a high internal surface area with lots of canals and chambers.
What is the name of the opening where water flows in through on the sponge?
Ostium
What feature defines the Phylum Porifera?
Collar Cells (Choanocytes) -They pump water and allow for particle feeding
How do Choanocytes work?
Flagellum in choanocyte beats back and forth causing pressure gradient
- water is sucked in through collar of microvilli
- particles are caught and eaten as they pass through the collar
What are Archaeocytes?
Ameoboid cells that live in the mesohyl
- They ingest, digest food caught by choanocyte collars (intracellular digestion)
- They are totipotent (can change into any sponge cell)
What is the mesohyl in the sponge?
Gelatinous extracellular matrix made of jelly like collagen
What is the major structural protein in Metazoa (including sponges)?
Collagen
How do sponges reproduce?
Sexual Reproduction
-Releasing sperm and creating eggs (hermaphroditic)
Asexual Reproduction
-Budding and/or Fragmentation
What else live in the cells or mesohyl of the sponge?
Symbiotic microbes that help produce unique organic compounds
What can the unique organic compounds produced by sponges/microbes be used for?
new sources of medicines
How do sponges accomplish Excretion/Respiration?
Diffusion
Do Sponges have germ layers, symmetry or are they protostomes or Deuterostomes?
No Germ Layers
No Symmetry
Not a protostome or deuterostome
What is the group Radiata and what Phyla are included in this group?
Radiata are the two phyla with radial symmetry
-Includes Phyla Cnidaria and Cnetophora
What kinds of tissues do Radiata have?
2 Germ Layers
-Endoderm and Ectoderm
No Mesoderm or organ systems
Do Radiata have a stomach?
No. They have a Gastrovascular Cavity (gut)
What environments do Radiata live?
Mostly Marine all aquatic. Some freshwater.
What species are included in Phylum Cnidaria?
Jellyfish, Anemones, and Corals
What is the defining characteristic of Phylum Cnidaria?
Presence of Cnidocytes
Do Phylum Cnidaria species move?
Some are Sessile (Corals) and some are Moblie (Jellyfish)
-The ones that are mobile don’t swim, they drift
Are Cnidaria diploblastic or triploblastic?
Diploblastic b/c they have 2 germ layers
How do Cnidaria reproduce?
Sexually and Asexually
What are the two bodyplans of Cnidaria?
Polyps and Medusae
What are the Classes under Phylum Cnidaria?
Cubozoa, Scyphozoa, Anthozoa, Hydrozoa
Describe the Phylum Cnidaria body plan.
Polyp - sessile, thin mesoglea
Medusa - free swimming, mobile
Mesoglea - jellylike layer thicker in medusa (acts as skelton)
How many openings are there to the gastrovascular cavity in Phylum Cnidaria?
THere is one opening (mouth) and the gastrovascular cavity somtimes acts as a skeleton
Where are the highest concentration of cnidocytes?
The tentacles
What are Cnidocytes?
Specialized epithelial cells that secrete the Cnide (Nematocyst)
- Nematocyst pressurized to 2000 psi
- May release toxins or digestive enzymes
What is the stimuli for discharge of the Cnide (nematocyst)?
The Cnidocil is disturbed or mechanoreceptor cells or chemoreceptor cells
What happens to the Cnidocyte after the Cnide (nemtocyst) is fired?
The Cnide is used up but the Cnidocyte isn’t. It will reproduce another nematocyst.
Where do epithelio muscular cells derive from in the Cnidaria since there is no mesoderm?
Derived from ectoderm
Why doesn’t water pass between cells in the Phylum Cnidaria?
The epidermis and gastrodermis are both epithilia with gap junctions that form a seal
Explain the reproduction and life histories of Phylum Cnidaria, Class Hydrozoa.
- Polyps for most of life
- Sexual reproduction occurs during medusa stage
- Makes Larva
- Larva uses asexual reproduction to build colony of polyps
- the polyps have gastrozooids to feed
- the polyps have gonozooids which sprout the medusa stage of the life history
Explain the reproduction and life histories of Phylum Cnidaria, Class Scyphozoa.
- Jellyfish for most of life
- female medusa egg is fertilized (sexual reproduction)
- the zygote develops into planula larva
- larva implants on surface and grows (polyp stage)
- eventually produce the ephyra (asexual reproduction) which grows into medusa stage
What species are included in Class Cubozoa?
box jellyfish and sea wasp
What species are included in class anthozoa? WHat are the features?
anemones and coral
- no medusa stage only polyp
- symbiosis with dinoflagellate, zooxanthellae allow corals to form reefs
Are Cnidaria protostomes or deuterostomes?
Neither
What is the skeletal system of Cnidaria?
mesoglea
How do Cnidaria feed?
Carnivorous, using nematocysts
How do Cnidaria accomplish excretion/respiration?
Diffusion
What Species are included in Phylum Cnetophora?
Comb jellies and sea gooseberries
What are the distinguishing characteristics of Cnetophores?
Cnetes or combs of 8 rows which move animal in the plankton
- all aquatic, all marine
- Colloblasts: sticky, snare prey (not cnidocytes)
