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http://www.google.com/imgres?hl=en&client=firefox-a&hs=SdX&sa=X&rls=org.mozilla:en-US:official&biw=1252&bih=610&tbm=isch&prmd=imvnsu&tbnid=CoM8BST1WRxKbM:&imgrefurl=http://www.funpicweb.com/jellyfish.html&docid=BSaJJsI8tHj7RM&imgurl=http://www.funpicweb.com/wp-content/uploads/2011/03/03_JELLYFISH.jpg&w=1024&h=768&ei=Yh32TtmRMoqQsQLH7dyYAQ&zoom=1&iact=rc&dur=186&sig=101830522278361665895&page=1&tbnh=105&tbnw=117&start=0&ndsp=21&ved=1t:429,r:9,s:0&tx=83&ty=48http://www.google.com/imgres?hl=en&client=firefox-a&hs=SdX&sa=X&rls=org.mozilla:en-US:official&biw=1252&bih=610&tbm=isch&prmd=imvnsu&tbnid=CoM8BST1WRxKbM:&imgrefurl=http://www.funpicweb.com/jellyfish.html&docid=BSaJJsI8tHj7RM&imgurl=http://www.funpicweb.com/wp-content/uploads/2011/03/03_JELLYFISH.jpg&w=1024&h=768&ei=Yh32TtmRMoqQsQLH7dyYAQ&zoom=1&iact=rc&dur=186&sig=101830522278361665895&page=1&tbnh=105&tbnw=117&start=0&ndsp=21&ved=1t:429,r:9,s:0&tx=83&ty=48 The Cnidarians! Forget the “C”” http://www.google.com/imgres?hl=en&client=firefox-a&hs=1Js&rls=org.mozilla:en-US:official&biw=1252&bih=610&tbm=isch&tbnid=VmHGAnx_kkB_XM:&imgrefurl=http://nationalzoo.si.edu/Animals/Invertebrates/Facts/cnidarians/Anthozoa.cfm&docid=JuAjwIzOHEGUrM&imgurl=http://nationalzoo.si.edu/Animals/Invertebrates/Facts/cnidarians/images/cover_greenanemone.jpg&w=200&h=200&ei=sB32TsPfDKm2sQKtvLSlAQ&zoom=1 They are everywhere!
Habitat • Found in every ocean and sea • Freshwater as well • Shallow and deep ocean environments • Very successful group
The 2 Body types Polyp Medusa http://www.sfu.ca/biology/courses/bisc306/index.html
The 2 Body types Polyp • Corals and anemones • Tentacles and mouth face UP and the other side is affixed to a substrate or a colony of the same species • Sessile in this form Medusa • Jellyfish • Upside down- Tentacles and mouth face DOWN • Motile in this form http://www.oceaninn.com/the-nature-preserve/cnidarians/
The 2 Body types • Most Cnidarians alternate between both body types • Some sea anemones and corals do not alternate • Questions: Which body type are the corals and anemones? • Polyp
3 Classes of Cnidarians Remember your mnemonic Hydrozoa Anthozoa Scyphozoa Alternate between polyp and medusa stage Medusa stage usually larger and more developed than the polyp The familiar jellyfish • true corals, anemones, sea pens, sea fans • Lack a medusa phase. • Small in size, usually mistaken for algae • Most alternate life stages between medusa and a polyp • Often form colonies • http://www.google.com/imgres?hl=en&client=firefox-a&hs=jVe&sa=X&rls=org.mozilla:en-US:official&biw=1252&bih=583&tbm=isch&prmd=imvns&tbnid=4NizC3IXZaNFZM:&imgrefurl=http://www.anthozoa.com/&docid=omGRFm9G58W69M&imgurl=http://www.anthozoa.com/Photos/Welcome/Anthozoans.jpg&w=600&h=450&ei=n4T2TqG7MtCOsALl5uXAAg&zoom=1
Cladogram based on molecular systematic data http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CCUQFjAB&url=http%3A%2F%2Ffaculty.mwsu.edu%2Fbiology%2Fjon.scales%2FCourses%2FZoology%2Flectoutlines%2F8_cnidaria.ppt&ei=PZP2TvWHJ-ixsALm0ui2AQ&usg=AFQjCNHSJGry_TVVRdnjBdX-WKKwLKsG6g
Where are they on the tree? What are the two levels of organization you see displayed in Cnidarians? http://www.oceaninn.com/the-nature-preserve/cnidarians/ Radial Symmetry and true tissues
Radial symmetry http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/bio%20102/bio%20102%20lectures/animal%20diversity/lower%20invertebrates/sponges.htm http://www.uic.edu/classes/bios/bios100/labs/animaldiversity.htm
Tissues • simplest organisms at the tissue grade of organization • Their cells are organized into true tissues.
Cnidarians are like bags made of two cell layers. The outer layer, or epidermis, contains the cnidocysts, the stinging cells that are characteristic of the phylum. • The inner layer, or gastrodermis, lines the gut. In between epidermis and gastrodermis is the mesoglea, a layer of jelly-like substance, which contains scattered cells and collagen fibers. The mouth is often, but not always, surrounded by a ring of tentacles. • The mesogleais not the same as a mesoderm! http://www.oceaninn.com/the-nature-preserve/cnidarians/
Diploblastic Cnidarians How many tissue layers do you see developing? 2
The Tissue layers http://biology.unm.edu/ccouncil/Biology_203/Summaries/SimpleAnimals.htm
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CCUQFjAB&url=http%3A%2F%2Ffaculty.mwsu.edu%2Fbiology%2Fjon.scales%2FCourses%2FZoology%2Flectoutlines%2F8_cnidaria.ppt&ei=PZP2TvWHJ-ixsALm0ui2AQ&usg=AFQjCNHSJGry_TVVRdnjBdX-WKKwLKsG6ghttp://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CCUQFjAB&url=http%3A%2F%2Ffaculty.mwsu.edu%2Fbiology%2Fjon.scales%2FCourses%2FZoology%2Flectoutlines%2F8_cnidaria.ppt&ei=PZP2TvWHJ-ixsALm0ui2AQ&usg=AFQjCNHSJGry_TVVRdnjBdX-WKKwLKsG6g
Digestion http://www.google.com/imgres?hl=en&client=firefox-a&hs=oqe&sa=X&rls=org.mozilla:en-US:official&channel=np&biw=1252&bih=610&tbm=isch&tbnid=czlUXbMfQ9rWoM:&imgrefurl=http://www.doctortee.com/dsu/tiftickjian/bio101/digestion.html&docid=MKwkEJj1OkC3CM&imgurl=http://www.doctortee.com/dsu/tiftickjian/cse-img/biology/animals/anat-phys/hydra-feeding.jpg&w=380&h=500&ei=CsD3TqGVCejisQKF-dD5CQ&zoom=1&iact=hc&vpx=272&vpy=122&dur=15996&hovh=258&hovw=196&tx=125&ty=111&sig=101830522278361665895&page=1&tbnh=143&tbnw=109&start=0&ndsp=19&ved=1t:429,r:1,s:0 Single opening serves as entrance and exit for: • Food + nutrients • Waste • Both intra and intercellular digestion. Enzymes are released into the body cavity and help break down food. • Food is then engulfed by cells lining the gut in a process called phagocytosis
How to put a Cnidarian in the tree continued… No. They are Acoelomate • Do they have a coelom??? • What is a coelom? • Fluid filled sac formed in mesoderm • Therefore only triploblastic animals can have one • Allows organs to grow off the body wall of an animal
Circulatory system? No thanks • Question: Why do Cnidarians not have/need a circulatory system? • Cells are close enough contact with water for simple diffusion to absorb and remove nutrients and gasses • Diffusion enhanced by water being moved by cilia in the Gastrodermis and/or muscular movements http://www.anselm.edu/homepage/bpenney/teaching/BI338/Phyla/Cnidaria.html
Level of Cephalization • First organisms to develop nervous system • Nerve-net , nerves spread throughout the body • Beginnings of centralization of nerves • Certain species developed ocelli –basic light sensing organs • Nerve centralization around these ocelli begins to occur. http://www.google.com/imgres?hl=en&client=firefox-a&hs=Rmt&rls=org.mozilla:en-US:official&biw=1252&bih=583&tbm=isch&tbnid=mLpKgqQ2E6lkpM:&imgrefurl=http://www.myoceandeep.blogspot.com/&docid=CWXsegTGA8rjEM&imgurl=http://4.bp.blogspot.com/_uzGBMr1t0s8/SYR4lfUQl3I/AAAAAAAAAYE/mn56WPLZZNI/s400/Jellyfish_4.jpg&w=400&h=300&ei=ljP2TvXIKa3fsQLz5bmxAQ&zoom=1&iact=rc&dur=382&sig=101830522278361665895&page=3&tbnh=107&tbnw=145&start=39&ndsp=21&ved=1t:429,r:12,s:39&tx=58&ty=47
The nerve-net Myoepithelial = cells with characteristics of muscle cells and epithelial (think skin) cells. http://www.sfu.ca/biology/courses/bisc306/index.html
Nerve net vid • Start at 3:21 • http://www.youtube.com/watch?v=S5xvagTFrv4&feature=related
Life Cycles and Reproduction • Asexual • Budding • Medusa buds • Polyp buds • Sexual • Gonadal tissue • Gametes (sperm or egg) • Fertilization, embryogenesis • Planula larvae http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CCUQFjAB&url=http%3A%2F%2Ffaculty.mwsu.edu%2Fbiology%2Fjon.scales%2FCourses%2FZoology%2Flectoutlines%2F8_cnidaria.ppt&ei=PZP2TvWHJ-ixsALm0ui2AQ&usg=AFQjCNHSJGry_TVVRdnjBdX-WKKwLKsG6g Dimorphic (two phase) life cycle
The different classes of cnidarians modify this lifecycle Show me in the chart how the following modify this life cycle phase Anthozoa Lack a medusa phase. Hydrozoa Most alternate life stages between medusa and a polyp Often form colonies Scyphozoa Alternate between polyp and medusa stage Medusa stage usually larger and more developed than the polyp Sperm and egg released
Video: ..\..\..\Lesson Videos\Biology 11\PortugeseManowar.flv • Notes: Which class of Cnidarian is the creature in the video? • What life stage is it in? • What are some special adaptations this organism has developed?
Portuguese Man-o’war or Bluebottle jellyfish There’s me surfing in Australia where I learned about stinging nematocysts first hand. https://encrypted-tbn0.google.com/images?q=tbn:ANd9GcQjR7M5UNsoU71gHiSBvxdoXV9vR1sfnbusm6x3mxdXdatAW5KvjQ 3 times https://encrypted-tbn1.google.com/images?q=tbn:ANd9GcQ_QbclQunYw8sU7wAB4U4A_nAG9gvzOlEhnjqKPvVXK-x5J01f1MrNG4C6vQ https://encrypted-tbn2.google.com/images?q=tbn:ANd9GcQTSB444Gg0vkqi-9iLO7PhVrJ_ErSfjcmnPBDsCwFO-XFyMBPdnQ
Nematocysts (ouch!) • Imagine trying to capture live prey without the aid of teeth, a jaw and hard protective body parts. • Video ..\..\..\Lesson Videos\Biology 11\How Do Jellyfish Sting_.flv http://jellieszone.com/nematocysts.htm
Nematocysts Nematocyst firing Hydrozoan capturing prey with nematocysts http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CCUQFjAB&url=http%3A%2F%2Ffaculty.mwsu.edu%2Fbiology%2Fjon.scales%2FCourses%2FZoology%2Flectoutlines%2F8_cnidaria.ppt&ei=PZP2TvWHJ-ixsALm0ui2AQ&usg=AFQjCNHSJGry_TVVRdnjBdX-WKKwLKsG6g
How Nematocysts function • An unused nematocyst is held within a cell known as a nematocyte • Most nematocytes are located on the tentacles of the Cnidarian, which are the primary food capturing part of the body. • Nematocysts are continuously produced. • They are not reused following discharge and it is energetically costly to produce them. • Therefore its best for a Cnidarian to fire only when necessary. • Touch or chemical stimuli may cause firing. • Osmotic pressure is thought to cause firing. • Spines and a twisting motion help the nematocyst to puncture the skin and inject the venomous tubule. • Cnidarians have developed many different and complex chemicals to inject. http://jellieszone.com/nematocysts.htm
Irukadnji – The box Jellyfish • ..\..\..\Lesson Videos\Biology 11\Box Jellyfish - Irukandji.flv
Draw some Cnidarians:Draw a Polyp and Medusa Include and label the following in your drawing: Endoderm cells Ectoderm cells Tentacles Nematocysts ALSO INCLUDE: mouth/anus • Gastrodermis
The Tissue layers http://biology.unm.edu/ccouncil/Biology_203/Summaries/SimpleAnimals.htm
..\..\..\Lesson Videos\Biology 11\Cnidaria Ability To Move.mov.flv • Take notes on anything we can use to fill out the 7 ways to survive sheet • Brainstorm the answers as a class • Watch the first 9 minutes:..\..\..\Lesson Videos\Science 8\optics\Eyes - Evolve - History Channel.flv