Phylum Cnidaria

DEFINING CHARACTERISTIC OF CNIDARIA

Contain Stinging cellsDidermicSac Body PlanGastro-vascular Cavity

STINGING CELL

STINGING CELL

Specialized Cell is Cnidocyte that contain

stinging organelle Nematocyst.

Nematocyst – has barbed and poisonous thread. They produced toxin when discharged, they help in the capture of prey or for defense

WHAT WILL HAPPEN WHEN JELLYFISH STING YOUR SKIN?

1. REMAIN CALM! THERE ARE ONLY A FEW JELLY FISH WHOSE STING IS DEADLY OR POTENTIALLY DEADLY. PANICKING WOULD BE UNHELPFUL.

How to Soothe a Jellyfish Sting

2. Get out of the water! Jellyfish stings can be extremely painful and you could lose your ability to swim

3. Remove stingers by applying shaving foam to the sting area. Scrape the skin closely with a razor, knife blade, or credit card. If you don't have a plastic card, rub sand over it to dislodge the stingers and rinse it off in salt water

4. Deactivate the remaining stingers. In the case of a plain old jellyfish sting, blot or pour 3-10% percent acetic acid solution (white vinegar) on the sting with a clean cloth.

5. Remove any venom in the skin by applying a paste of baking soda and water and using a cloth covering. If possible, reapply paste every 15-20 minutes.

6. Take a very hot shower. A 15-20 minute hot shower can deactivate the venom of some jellyfish

7. Soothe any remaining skin irritations with over-the-counter antihistamine pills.

8. Get medical care if the victim is experiencing any symptoms worse than skin irritation or has trouble breathing.

10. Severe stings need to be wrapped after treatment to keep them from getting infected

DIDERMIC

Consist of 2 tissue layer

Epidermic Gastrodermis

SAC BODY PLAN

The mouth serve as an incurrent and excurrent opening

GASTROVASCULAR CAVITY

Play an important role in Digestion. Inner Cell

dependon water within the cavity

for gas exchange and excretion.

ANATOMY OF CNIDARIA

Tentacles – contain sting cell use in capturing prey

Oral arm – Hold the prey then pass out in the mouth

Mouth – serve for food entrance, metabolic waste exit and passageway of gametes.

Nerve Net – nerve cells interconnect to form a nerve net below the epidermis

Epidermis – outer covering of Cnidaria

Gonads – responsible for production of gametes

REPRODUCTION

The life cycle of Cnidaria include two phases:When there is an alteration of Generation Medusa – the sexual phase Polyp – asexual phase

Polyp – has mouth on the dorsal surface and tentacles that point upward

Medusa – has a mouth on the ventral surface and tentacles that point downward

LIFE CYCLE OF CNIDARIA

1. The adult male and female sea jellies releases gametes

2. Fertilization occur in the water. Zygote will form that eventually develop into a planula

3. The planula will eventually settle and attaches to a firm surface. The planula then develops into a polyp with a mouth and tentacles on its unattached end. The polyp will develop a stack of medusa that will bud off.

4. The polyp will bud off immature sea jelly or ephyra then it will develop into an adult sea jelly.

CLASSES OF CNIDARIA

•Scyphozoa•Anthozoa•Hydrozoa•Cubozoa

SCYPHOZOA

Cnidaria with dominant medusae

Aurelia auritaCyanea capillata

CUBOZOA

The medusae is in cuboidal shape with tentacles that hang from each corner of bell

Chironex flexeri Chiropsalmus quadrumanus

STAUROZOA

Goblet-shaped, sessile, attached by oral stalk to sea weeds

Halyclystus auricula

HYDROZOA

Cnidaria with polyp dominant

One of the few fresh water cnidaria

They are also found in attached to underwater plant or rocks, mostly in lakes and ponds.

Hydra Obelia

ANTHOZOA

Stony coral, with no medusae have a calcium carbonate exoskeleton that contribute greatly building of coral reef.

Fungia Corallium

IMPORTANCE OF CNIDARIA

THEY PROVIDE HABITAT FOR MANY MARINE ORGANISM

THE REEF DECREASES THE FORCE OF THE INCOMING WAVES, RESULTING IN PEACERFUL WATER AT THE SHORE

SEA CORALS ARE GOOD INDICATOR OF ENVIRONMENTAL CHANGES. SEA CORALS ARE VERY SENSITIVE TO SUCH FACTOR AS WATER POLLUTION

Multiple Choice. Choose the best answer in the following question

1. The jelly like layer in the cnidaria body walla.Nematocyst c. Mesoglea b. Mesohyl d.Gastrocoel 2.The asexual phase of cnidariaa.Polyp c. Both polyp and medusa c. Medusa d. None3.What do you call the free living larva of Cnidaria?a.Planula b. Clydippids c.Nymphs d. Lanula

4.Which of the following is NOT a Cnidarian Characterisitic?

a.Contain stinging cell c. Didermicb.Triploblastic d.Sac Body Plan

5.Halyclystus belong to what class?a.Staurozoa c. Hydrozoab.Cubozoa d. Anthozoa