Phylum Coelenterata(phylum Cnidaria) Zoology June 4, 2014 Mrs. McCarthy
Classification A. 2 phylum names 1. Coelenterata – hollow gut 2. Cnidaria – nettle
Basic Characteristics A. Tissue level 1. Sac – like body with 3 layers a. epidermis b. mesoglea c. gastrodermis 2. Gastrovascular cavity – hollow internal body cavity B. Nervous system 1. Nerve net – nerves evenly spaced 2. Statocysts – structures for balance (hollow ball of cells with a grain of sand) 3. Ocelli – light sensitive structure
C. Tentacles 1. Capture food 2. Cnidoblast/cnidocyte – cell that contains the stinging organelle 3. Nematocyst – stinging organelle a. capsule with coiled “harpoon” containing toxins b. Operculum – flap that holds the coil inside c. Stimulated by touch and chemicals
D. Habitat 1. Mostly shallow, marine 2. Pelagic – open water 3. Benthic – bottom dweller 4. Symbiosis a. on other animal’s shells b. with algae that provide energy from photosynthesis
E. Reproduction 1. Polymorphism “many shapes” 2. Polyp – sessile, tentacles up 3. Medusa – floating, tentacles down 4. Many alternate forms 5. Asexual reproduction a. budding b. regeneration 6. Sexual reproduction a. mostly dioecious
Class Hydrozoa – “water animal” A. Hydra – freshwater polyp 1. Basal disk at the bottom 2. 6 – 10 tentacles 3. Hypostome – raised area around the mouth 4. Eat small crustaceans, insect larvae, tiny worms
5. Locomotion a. sliding along on basal disk b. inch – worm c. floating with gas bubble d. epitheliomuscular cells for covering and contraction
6. Reproduction a. asexual b. sexual 1. Sperm released into water 2. Eggs fertilized in female 3. Ciliated larva is released, develops into adult
B. Hydroid colonies 1. genus Obelia – polymorphic life cycle
C. Portuguese Man-O-War 1. genus Physalia 2. Floating colony of individual animals 3. Pneumatophore – the float on the surface
Class Scyphozoa – “cup animal” A. genus Aurelia – common jellyfish B. Thick mesoglea C. Tentacles can be up to 70 m D. Dioecious, polymorphic life cycle
Class Cubozoa – “cube animal” A. Square shaped medusa B. Australian box jelly – one of the most poisonous animals in the world Chironex fleckeri (the sea wasp) is the deadliest jellyfish in the ocean.
Box Jelly sting scars • box jelly link
Two concepts are key to treating box jellyfish stings. One is to prevent firing of any undischarged nematocysts remaining on the skin, thus preventing the injury from getting worse. The second is to treat the symptoms and pain caused by already-fired nematocysts. The following first aid treatment, based on current Australian research, is recommended for the stings of all species of box jellyfish: • Immediately flood the area with household vinegar to keep undischarged nematocysts from firing. This does not relieve pain, but prevents additional stings. • Never rub the area with sand or anything else. • Irrigate exposed eyes with copious amounts of room temperature tap water for at least 15 minutes. If vision blurs, or the eyes continue to tear, hurt, swell, or are light sensitive after irrigating, see a doctor. • Pluck off any vinegar-soaked tentacles with a stick or other tool. • If the victim has shortness of breath, weakness, muscle cramps, palpitations or any other generalized symptoms, take them to an emergency room. • For pain relief, apply ice packs. If pain becomes unbearable, go to an emergency room. No studies support applying heat to box jellyfish stings.
Contradictory studies exist on the effectiveness of meat tenderizer, baking soda, papaya, or commercial sprays (containing aluminum sulfate and detergents) on nematocyst stings. These substances may cause further damage. Some kinds of meat tenderizer, for instance, can cause skin peeling. In one U.S. fatality from the box jellyfish, Chiropsalmus quadrumanus, rescuers placed meat tenderizer almost immediately on the affected arm. The child was soon comatose and later died. • Alcohol and human urine are common nematocyst remedies, but both can be harmful. An Australian study reports that both alcohol and urine caused massive discharge of box jellyfish nematocysts.
Class Anthozoa – “flower animal” A. Large gastrovascular cavity separated by mesenteries to increase surface area for digestion B. genus Metridium – sea anemone 1. Live symbiotically with algae, crabs, and clown fish 3. Some are protandrous
C. Corals are colonial 1. True corals have secreted calcareous cups 2. Thorny corals are branched 3. Tube anemones 4. Hermatypic corals – reef building a. fringing reef – close to land mass with a very narrow lagoon b. barrier reef – parallel to shore with a wide, deep lagoon c. atoll – encircles a lagoon, usually on a submerged volcano
Classification Kingdom Animalia Phylum Coelenterata (Cnidaria) Class Hydrozoa Hydra Genus Obelia Genus Physalia Portuguese Man-o-war Class Scyphozoa Genus AureliaCommon jellyfish Class Cubozoa Australian Box Jellyfish Class Anthozoa Genus Metridium Sea anemone Corals