Chordata

1. Chordata Intro, Urochordata and Cephalochordata Victor Pontis & Kaushik Sahoo AP Bio Period 3 Rall http://www.aboututila.com/PhotoGallery/DeepBlue/Photos/Bluebell-Tunicate-01.jpg

2. Intro to Chordata http://myphlip.pearsoncmg.com/altcc/student/ab2page.cfm?vbcid=10440&vid=19992

3. Characteristics of Chordata Deutorosomes, Bilaterally Symmetrical • Four key characteristics: • Notochord - skeletal • Dorsal, hollow nerve cord - CNS • Pharyngeal slits or clefts – “gills” • Muscular, post-anal tail http://myphlip.pearsoncmg.com/altcc/student/ab2page.cfm?vbcid=10440&vid=19992

4. Nicknamed "Sea Squirts" Has body cavity that holds the atrium Bilaterally Symmetrical Nervous system degenerates after larval stage. Some cells detect light and gravity allowing it to settle on a substrate. Limited nervous system in adult stage.  Tunicates Overview Tunicates are members of the subphylum Urochordata http://www.marinemedicaltreasures.com/images/tunicates.jpg

5. Incurrent siphon sucks water Atrium filters food Water and waste excreted through excurrent siphon Food travels from esophagus to stomach Siphons also function as circulatory system Digestive, Excretory, and Circulatory Systems http://myphlip.pearsoncmg.com/altcc/student/ab2page.cfm?vbcid=10440&vid=19992

6. Uses tail muscles and notochord to swim as a larvae Excurrent siphon can do jet propulsion Locomotion/Musculature

7. Larval stage has notochord and dorsal, hollow nerve chord In adult form the skeleton is lost and resorbed Light and gravity sensing cells Skeletal Type/Sensory Structures

8. Hermaphrodite = both male/female Settles on substrate Light and gravity cues Chordate characteristics disappear as adult Reproduction

9. Water is sucked in and pushed out through siphons Diffusion Gas Exchange

10. Sample Example Organisms Class: AscidiaceaOrder: PleurogonaSuborder: StolidobranchiaFamily: PyuridaeGenus: HalocynthiaSpecies: H. roretzi Sea Pineapple http://upload.wikimedia.org/wikipedia/commons/7/7e/Halocynthia_roretzi-Sea_pineapples_at_Tsukiji_Market-01.jpg http://www.biodiversity911.org/biodiversity_basics/why_important/images/red_sea_tunicates.jpg

11. Lancelets/Cephalochordata • In the lavaral form lancelets develop a notochord, a dorsal, hollow nerve cord, numerous pharyngeal slits, and a post-anal tail. • Body Cavity is present. • Bilateral Symmetry • Feed on plankton. • Adult lancelets up to 5 cm long • Frequently swim to new locations • Lanclets- globally rare http://myphlip.pearsoncmg.com/altcc/student/ab2page.cfm?vbcid=10440&vid=19992

12. Nervous System • Lancelets develop a hollow nerve cord • Have slightly swollen tip on the anterior end of their dorsal nerve cord • However, no true brain http://myphlip.pearsoncmg.com/altcc/student/ab2page.cfm?vbcid=10440&vid=19992

13. Circulatory System • Water enters mouth and passes through the pharyngeal slits into the atrium • The atrium is a chamber that vents to the outside by way of the atriopore • No heart and blood cells

14. Digestive System/Excretory System • Mucous net around pharyngeal slits remove small food particles from seawater • Ciliary pumping draws these particles into the mouth • Trapped food enters the intestine • Food finally leaves through anus

15. Locomotion/Musculature • Swimming mechanism of fishes • Coordinated contraction of muscles • Serially arranged segmental muscles  • Muscle segments develop from blocks of mesoderm-Somites • Undulatory (wavelike) movements

16. Skeletal Type/Sensory Structures • As larvae develop a dorsal, hollow nerve cord and notochord • Somites found along each side of notochord • Tentacles by mouth act as sensory devices, and as a water filter • No eyes, or complex sensory structures

17. Reproduction • Sexual Reproduction • Lanclets have separate sexes - Male & Female • Eggs and Sperm released into water • Fertilized eggs develop into larvae

18. Gas Exchange • Diffusion across external body surface • Pharynx and Pharyngeal slits play a minor role in gas exchange

19. http://www.uic.edu/classes/bios/bios100/labs/lance.jpg Lancelets are globally rare, but can reach large densities (5000/m2) in areas like Tampa Bay http://cfs15.tistory.com/image/32/tistory/2009/02/01/04/13/4984a2d26fa8e

20. QUIZ TIME! 1) Which of following outline the notochord, and     are prevalent in all chordate embryos? A. Atriums B. Somites C. Siphons D. Tunics

21. QUIZ TIME! 1) Which of following outline the notochord, and     are prevalent in all chordate embryos? A. Atriums B. Somites C. Siphons D. Tunics

22. QUIZ TIME! 2) Mature tunicates are able to move by  A. their muscles. B. clinging to other animals as they pass by. C. teleportaion.  D. jet propulsion.

23. QUIZ TIME! 2) Mature tunicates are able to move by  A. their muscles. B. clinging to other animals as they pass by. C. teleportaion.  D. jet propulsion

24. QUIZ TIME! 3. Chordates are A. bilaterally symmetrical. B. radially symmetrical. C. not symmetrical at all. D. aesthetically symmetrical. 

25. QUIZ TIME! 3. Chordates are A. bilaterally symmetrical. B. radially symmetrical. C. not symmetrical at all.   D. aesthetically symmetrical. 

26. QUIZ TIME! 4. Tunicates _____ and Lancelets _____. A. are sexual; are asexual B. are asexual; are sexual C. have separate sexes; are hermaphrodites D. are hermaphrodites; have separate sexes

27. QUIZ TIME! 4. Tunicates _____ and Lancelets _____. A. are sexual; are asexual B. are asexual; are sexual C. have separate sexes; are hermaphrodites D. are hermaphrodites; have separate sexes