Presentation on theme: "Good Afternoon! On a sheet of paper (it can be a half sheet) tell me 5 things that you remember about Jellyfish from the movie on Friday! You will be turning."— Presentation transcript:
1 Good Afternoon!On a sheet of paper (it can be a half sheet) tell me 5 things that you remember about Jellyfish from the movie on Friday!You will be turning this in 5 minutes after the bell rings
3 Cnidarians This term is not used often anymore! Phylum CnidariaIncludes jellyfish, anemones, corals, & sea pensNext level of complexity after spongesTissues are specialized to perform specificfunctions.Also called coelenteratesThis term is not usedoften anymore!
4 Coelenterates Refers to 2 Phylums combined: Ctenophora: Comb Jellies Even though not used often anymore…Refers to 2 Phylums combined:Phylum Cnidaria & Phylum CtenophoraCtenophora: Comb JelliesCnidaria: Jellyfish, Sea anemones, Corals, & Sea pensHave a hollow body cavity, & verysimple tissue organization
5 Cnidarians Have NO bones Have NO heart Have NO brain Have NO “real” eyesHave NO respiratory system
6 Cnidarians: Body PlanDisplay radial symmetry, which is aregular arrangement of similar body parts around a central axis.Look the same from all sidesHave no head, front, or back
7 Cnidarians: Body PlanHave an oral surface where the mouth is & an aboral surface on the opposite side.
8 Polyp: A sac-like attached stage (sessile) Medusa: Bell-like stage Occur as 2 basic forms:Polyp: A sac-like attached stage (sessile)Medusa: Bell-like stageSome experience both forms during their life time, and others spend their entire lives as one of the two forms.MedusaPolyp
9 Cnidarians: Anatomy Have a centrally located mouth surrounded by tentacles which are slender, finger likeextensions.Use tentacles to catch & handle food
10 Cnidarians: AnatomyThe mouth opens into a gut (enteron) where food is digested.- The gut has only one opening, the mouth.
11 This is how jellyfish got their name. Cnidarians: AnatomyThe mesoglea is extremely thick, has ajelly like consistency & makes up thelargest portion of the animalThis is how jellyfish got their name.
12 How Cnidarians StingAt the narrow outer edge of the cnidocyte is a short trigger hair called a cnidocil (“trigger”).Upon contact with prey, the contents of the nematocyst are explosively discharged, firing a dart-like thread containing neurotoxins.
13 How Cnidarians StingThese stinging cells contain poison arrows connected to threads called nematocyts.* Cnidarians can still sting when they are dead!!
14 TentaclesThey capture small prey by discharging their cnidocytes (stinging cells), which are unique structures found on the tentacles.
15 TentaclesThe tentacle then brings the victim to the mouth to be digested.The food passes through the body cells, and the waste must go back out of the mouth.
21 Gastrovascular Cavity: A digestive chamber with one opening. FeedingAfter paralyzing its prey, a cnidarian pulls the prey through its mouth and into its gastrovascular cavity.Gastrovascular Cavity: A digestive chamber with one opening.Food enters & waste leaves the body throughthat opening.
22 Response to Environment Cnidarians gather information from their environment using specialized sensory cells.Both polyps & medusas have a nerve net.Nerve Net: A loosely organized network of nerve cells that together allow cnidarians to detect stimuli such as the touch of a foreign object.
23 Response to the Environment Cnidarians have statocysts which are groups of sensory cells that help determine the direction of gravity.Ocelli are eyespots made of cells that detect light.
24 MovementHydrostatic Skeleton: consists of a layer of circular muscles & a layer of longitudinal muscles that together with the water in the gastrovascular cavity, enable the cnidarian to move.Medusas move by jet propulsion.Muscle contractions cause the bell-shaped body to close like a folding umbrella.This action pushes water out of the bell, moving the medusa forward.
25 Cnidaria Reproduction Some reproduce asexually by budding (in polyps)Some reproduce sexually by releasing gametes.Some sexual forms are monoecious and others are dioeciousEggs and sperm are released into the stomach and then through the mouth into the sea.
26 Cnidaria Reproduction In some cases, to reproduce, a male releases his sperm into the surrounding water (spawn).The sperm then swims into the mouth of the female jellyfish, allowing the fertilization of the ova.
27 Cnidarian Reproduction In other cases, sexual reproduction takes place with external fertilization in water:External Fertilization: Takes place outside the body.The male & female releases eggsand sperm at the same time.
30 Types of Cnidarians: Hydrozoans Class HydrozoansHydraThey can be found in most unpolluted fresh-water ponds, lakes, and streamsThey are usually a few millimeters long and are best studied with a microscopeHydra has a tubular body secured by a simple adhesive foot called the basal disc.
31 Types of Cnidarians: Hydrozoans Class HydrozoansHydraAt the free end of the body is a mouth opening surrounded by one to twelve thin, mobile tentacles.Hydras are generally sedentaryor sessile, but can move,especially when hunting.31
32 Types of Cnidarians: Hydrozoans HydraThey move by bending over and attaching themselves to the substrate with the mouth and tentacles & then release the basal disc.The body then bends over and makes a new place of attachment with the foot.They “inch-worm” or“somersault” to move32
33 Types of Cnidarians: Hydrozoans Class HydrozoansPortuguese man-of-warConsist of feather or bushy colonies of polyps.- Some polyps are specialized floats, whichmay be gas-filled- Other polyps form the long tentacles used tocapture prey.33
34 Types of Cnidarians: Hydrozoans Portuguese Man-of-War
36 Types of Cnidarians: Scyphozoans Class ScyphozoanIncludes jellyfishHave a rounded body, or bell.Swim w/ rhythmic contractions of the bell, but swimming ability is limited & are carried by ocean currents.
37 Class Scyphozoans 95% of body is made of water Here before dinosaurs and sharksInhabit all oceans of the world
39 Moon Jellyfish Life Cycle PlanulaEach jellyfish is either male or female1. Males release sperm into surrounding water2. Eggs get suck in pits on the oral arms, and are fertilized by sperm3. The egg develops into a planulaPlanula is the larval stage, small, & covered in cilia4. The planula settles on a hard surface & develops into a polyp to become sessile
40 Moon Jellyfish Life Cycle 5. The polyp begins reproducing asexually by budding, and now called a scyphistoma6. Budding produces miniature medusae called ephyrae7. After ephyrae are released, they gradually grow into adult forms
42 Class Scyphozoans: Importance * Jellies are considered a delicacy by many people.* Low in fat & calories* Rich in nutrients.* Others claim they taste like rubber bands.
43 Class Scyphozoans: Importance * Food source for fish, sea turtles, and other organisms
44 Looks like a Jellyfish to sea, but isn’t! Clear plastics (such as bags and balloons) are often mistaken for jellyfish by animals such as the endangered leatherback sea turtle. When they eat plastic, these animals will often starve to death as the plastic clogs their intestines and they can no longer digest food.
45 Save the Sea Turtles!Recycle Plastic Bags & Make sure they do not find their way into the ocean!
46 Class Cubozoans Some are among the most dangerous marine animals. * Sea wasp, also known as the box jellyfish, of Australia & Southeast AsiaExtreme pain immediately when touched by tentaclesWithin minutes, heart failure may occur
48 Types of Cnidarians: Anthozoans Class AnthozoanIncludes sea anemones & coralsSolitary or colonial polypsLack medusa stageHave more advanced gut – contains several thin partitions called septa that provide extra surface area for digestion of larger prey.
50 Sea Anemones: Large muscular polyps. Types of AnthozoansSea Anemones: Large muscular polyps.
51 Sea Anemone Importance: Provides Homes Clownfish are protected from the anemones’ stinging cells by their mucus. They catch food and feed the anemone. Eggs are laid near or under the anemone and tended and protected by the male clownfish.
52 Types of Anthozoans/Corals Stony Corals:- Calcium carbonate skeletons that form coralreefs- More common in tropics
53 What do Corals Need to Survive? 1. Good Water Quality:Low turbidity (cloudiness or haziness of water)Temperature: at least 68° F2. Sunlight:Algae that lives inside corals must have sunlightThis is why corals do not live in deep water3. Zooplankton:Corals eat zooplankton4. Water Movement:Access to foodFlushes sediments off the coralso they can access sunlight
58 Mutualism in Anthozoans/Corals Mutualism: A relationship between two species that benefits both members. The association is necessary to both species.Corals & Zooxanthellae are mutualisticZooxanthellae: an algae-- Live in the tissues of coral polyps-- All reef building corals have them-- Helps corals synthesize (make) calcium carbonate
59 Why Coral Reefs are Important 1. Protect from soil erosion: Waves from the ocean crash onto the shore and over time erode the shoreline.* Coral reefs that border land act as a buffer for theharsh waves.* The reefs cause the waves to slow down or stopthem completely.* This prevents erosion of the shoreline and potentialproperty damage.
60 Why Coral Reefs are Important 2. Breeding Grounds & Shelter: Some species that do not even live in the reef may travel to that reef just to breed.* Coral reefs are very important for replenishing fishpopulations that people consume.60
61 Why Coral Reefs are Important 3. Tourism & Fisheries: They are important for fisheries & tourism businesses. Restaurants, hotels, SCUBA rentals, boat rentals, tour guides, air travel, cruise lines, and many more industries profit from healthy coral reefs.61
62 Coral Atolls Atolls are coral islands. The center of the atoll is a shallow lagoon.Formed when a volcanic island’s middle sank into theocean, and left a ring of landThe island bit of the atoll is a narrow ring of land around the lagoon, with coral reefs all around the outside of the island.
63 EcologyCrown of Thrones Starfish: Well known for its voracious appetite for live hard-corals.One explanation for local population explosions of these destructive starfish is the collection of this starfish's natural enemy, the Triton TrumpetMany scuba clubs organize "starfish hunts" in which these starfish are rounded up in an effort to save reefs from destruction.
64 Ecology: Coral Bleaching The whitening of coral colonies is due to the loss of symbiotic zooxanthellae from the tissues of polyps.Pollution, temperatures, & disease are being blamed for corals losing their zooxanthelle.
65 Stings from Cnidarians Symptoms* Includes corals, jellies, & sea anemones* Painful raised lesions in lines* Muscle spasms may develop* Raised lesions may fill with puss* May cause nausea, vomiting, dizziness,headaches, irregular heart rate
66 Stings from Cnidarians Treatment* Remove any tentacles (ex: stick)– Lift off skin, don’t scrape off-- Don’t use fingers, tentacles can still sting* Rinse with sea water to wash awaynematocysts left on skin* Rinse with vinegar – neutralizes nematocysts-- If there is no vinegar, then urine will work
67 Stings from Cnidarians Treatment Continued* Can apply Hydrocortisone is redness persists* Seek medical attention if muscle spasmsdevelop-- Doctor will give you calcium gluconate in IV
68 Death by Cnidarians Stings are usually mild Some stings are fatal * Box jellyfish -- Mortality rate of about 20% in1st 3 minutes of a stingThere isn’t an international data base for mortalities by jellyfish stings – exact numbers of deaths are unknown.
69 Look like Cnidarians, but are classified in a different phylum Phylum CtenophoraLook like Cnidarians, but are classified in a different phylum