1 / 21

Cnidarians

Cnidarians. Sandra Benito J.H., 9B. Facts. Name : Cnidarians Before: Coelenterata phylum, meaning "hollow guts." Included certain ctenophores and sponges. From the Greek "cnidos," meaning "stinging nettle.“ Number of species currently existing: 10,105 species Taxonomic Classification:

neil
Download Presentation

Cnidarians

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cnidarians Sandra Benito J.H., 9B

  2. Facts

  3. Name: Cnidarians • Before: Coelenterata phylum,meaning "hollow guts." • Included certain ctenophores and sponges. • From the Greek "cnidos," meaning "stinging nettle.“ • Number of species currently existing: 10,105 species • Taxonomic Classification: • Domain:Eukaryota • Kindom: VI. Animalia • Phyla: B.Cnidaria • Class:Cubozoa (Box jellies) Swimming • Class:Scyphozoa (Jellyfishes) Swimming • Class:Anthozoa (Anemones and corals) Sessile • Class: Hydrozoa (Hydra) Both

  4. Characteristics

  5. Found in marine environments. • Two basic body types: • Polyps • Medusae • Tentacles • Venomous cell organelles (cnidea) • Gastrovascular cavity • Three-layered body; epidermis, mesoglea and gastrodermis • Radially symmetric • Carnivorous • Solitary or colonial • Asexual and/or sexual reproduction • Nervous system • No cardiovascular system

  6. History

  7. Fossil history: • Vendian/Ediacaran period • 650 to 540 million years ago • Soft-bodied organisms • Cambrian period - coral fossils • Early Ordovician - more developed corals

  8. Generalized Life CycleAnd Life Expectancy

  9. Life span is undetermined. • Life cycles vary by class and species • Some skip stages (e.g. Hydra) • Alternation of generations (e.g. Obelia) • Asexual reproduction medusae grows on external tissue • Matured medusae swim away • Sexual cells released • Eggs are fertilized • Zygote/planula settles and develops into a polyop

  10. Digestive System

  11. Absorbdissolvedorganicchemicals • Filterfoodparticles • Nutrientsfromendosymbioticalgae • Predate • Crustaceans and plankton • Medusae forms sink on top of the prey • Gastrodem layer releases enzymes that kill the prey • Cellsabsorbthenutrients • Nutrients spread by diffusion or mobile cells • Indigestible remnants are ejected

  12. Respiratory andCirculatory System

  13. No circulatory system • No respiratoryorgans • Absorb/expel O and CO2 into water • Water in digestive cavity is expelled

  14. Sensory System

  15. Simple sensorysystem • Net of nerves made of sensitive neurons • Sensitive neurons are connected by chemical synapse • Neuron sends neurotransmitter (chemical) to cell group

  16. Bibliography • New Oxford American Dictionary • http://en.wikipedia.org/wiki/Cnidaria • http://waynesword.palomar.edu/trnov01.htm#animals • http://www.buzzle.com/articles/jellyfish-facts-for-kids.html • http://animals.about.com/od/cnidarians/p/cnidaria.htm • http://nationalzoo.si.edu/Animals/Invertebrates/Facts/cnidarians/default.cfm • http://www.oceaninn.com/the-nature-preserve/cnidarians/ • http://mapress.com/zootaxa/2011/f/zt03148p012.pdf • http://animals.about.com/od/cnidarians/ss/cnidarians.htm • http://www.ucmp.berkeley.edu/cnidaria/cnidariafr.html • http://www.angelfire.com/moon2/asciencems/ • http://zoology.muohio.edu/crist/Zoo312/Cnidaria.html • http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/bio%20102/bio%20102%20lectures/nervous%20system/nervous1.htm

More Related