1 / 27

Lab 7: Animals I: Porifera, Radiata, and Introduction to Bilateria

Lab 7: Animals I: Porifera, Radiata, and Introduction to Bilateria. Part A: Sponges (Phylum Porifera). video spongin (collagen). No Symmetry (asmmetrical); no true tissue. Task A-1 : Sponges (Phylum Porifera). Slide: Scypha – look for holdfast, osculum Slide: sponge spiculues

bela
Download Presentation

Lab 7: Animals I: Porifera, Radiata, and Introduction to Bilateria

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. Lab 7: Animals I: Porifera, Radiata, and Introduction to Bilateria

  2. Part A: Sponges (Phylum Porifera) • video • spongin (collagen) No Symmetry (asmmetrical); no true tissue

  3. Task A-1: Sponges (Phylum Porifera) • Slide: Scypha – look for holdfast, osculum • Slide: sponge spiculues • body types: simple, intermediate, complex – draw arrows on Fig. 7-3; look at specimens

  4. Part B: Phylum Cnidaria • have true tissues • radial symmetry • have stinging cells (cnidocytes) on tentacles and elsewhere • tentacles surround mouth • gastrovascular cavity with extracellular digestion; one opening serves as both mouth and anus • after larval stage (planula), polyp and/or medusa stage(s)

  5. Fig. 44.8

  6. Part B: Phylum Cnidaria • three classes • Hydrozoa – hydroids • Scyphozoa – jellyfish • Anthozoa – sea anemones and corals

  7. Task B-1: Phylum Cnidaria • Hydrozoa – hydroids • usually have both polyp and medusa stages • example: Hydra (solitary freshwater organism) • slides: look for tentacles, bud, cnidocytes, gastrovascular cavity, mouth, epidermis and endodermis (gastrodermis) with mesoglea between • living specimen – note its movement, look for external structures

  8. Task B-1: Phylum Cnidaria • Hydrozoa – hydroids (continued) • example: Obelia (colonial marine organism) • slides: note structures from Fig. 7-6 (feeding polyps, reproductive polyps, medusa buds, medusae, tentacles, gonads, mouth, gastrovascular cavity, etc.) • example: Portuguese man-of-war (colonial) • note both polyps and medusae in a colony that has superficial resemblance to a large medusa

  9. Task B-1: Phylum Cnidaria • Scyphozoa – jellyfish • dominant medusae; some have no polyp form • example: preserved specimen – treat it gently! • note tentacles, oral arms, mouth, gastrovascular cavity, gonads, thick jelly-like mesoglea

  10. Task B-1: Phylum Cnidaria • Anthozoa – sea anemones and corals • polyp stage only • sea anemones – very muscular • some sessile, but not all (…see video) • example: preserved specimen (treat gently!) • note mouth, tentacles, pedal disc

  11. Task B-1: Phylum Cnidaria • Anthozoa – sea anemones and corals (continued) • corals • most secrete calcium carbonate exoskeletons • look at dry coral specimens; note distinct cups indicating origins from separate polyps

  12. Part C: Bilateria • Bilateria – animals with bilateral symmetry • associated with cephalization (forming a true head) • learn dorsal/ventral and anterior/posterior

  13. Fig. 44.3b

  14. Part C: Bilateria • different forms based on fluid-filled body cavity • acoelomate – no body cavity • pseudocoelomate – body cavity bound by mesoderm on one side, endoderm on the other • coelomate (or eucoelomate) – “true” body cavity, surrounded by mesoderm on both sides

  15. Fig. 44.4

  16. Coelomates • coelom surrounded by mesodermal tissue (also called eucoelom) • allows for more complex organs, especially digestive system

  17. Part C: Bilateria • body cavities allow many things, such as hydrostatic skeleton, internal organs, circulatory system, etc. • coelom allows for more specialization than pseudocoelom does

  18. Part C: Bilateria • Two major clades within Bilateria: Protostomia (covered in this lab and lab 8) and Deuterostomia (covered in lab 9) • Within Protostomia, two major clades

  19. Part C: Bilateria • non-molting protostomes (labs 7 and 8) • vs. • molting protostomes (lab 8) • Two selected non-molting phyla covered in this lab: • Phylum Platyhelminthes – flatworms • Phylum Annelida – segmented worms

  20. Part C: Phylum Platyhelminthes – flatworms • acoelomate • dorsoventral flattening in most • incomplete digestive tract, when present (combo mouth/anus, just like Cnidarians) • most are parasitic; some are hunters • hermaphroditic • ….video

  21. Task C-1: Phylum Platyhelminthes – flatworms • 3 classes • Turbellaria • Cestoda – tapeworms • Trematoda – flukes • examine specimens and slides, look for structures noted in Figs. 7-10, 11, and 12 such as ocellus, pharynx, intestine, scolex, proglottids

  22. Part C: Segmented Worms (Phylum Annelida) • segmented – linear repetition of body parts; specialization in some (such as head); often separated by septa • use coelom for hydrostatic skeleton • closed circulatory system • excretory tubules (metanephridia) • most have chitinous bristles (setae) on most segments – for sensing, and locomotion

  23. Task 2: Segmented Worms (Phylum Annelida) • 3 classes • Polychaeta (polychaetes) • Oligochaeta (earthworms) • Hirudinea (leeches)

  24. Task C-2: Segmented Worms (Phylum Annelida) • annelid box and slide: examine the preserved specimens and slide, note the following: • Polychaeta – clamworm: • distinct head with tentacles, eyes, jaws • fleshy parapodia on segments – used for locomotion • compare to plume worm (not in box – demo only)

  25. Task C-2: Segmented Worms (Phylum Annelida) • annelid box and slide: • Oligochaeta – earthworm: • rub to feel chitinous setae, used for holding to soil • clitellum – band used in mating; is nearer to the anterior end of the worm • reproductive pores anterior to clitellum (earthworms are hermaphroditic) • cross-section slide: compare to Fig. 7-14, note structures bolded in you manual such as coelom

  26. Task C-2: Segmented Worms (Phylum Annelida) • annelid box: • Hirudinea – leech: • dorsoventral flattening • lack of setae and parapodia • less distinct segmentation • suckers for attaching to host for feeding (leeches are blood-sucking parasites)

  27. TODAY YOU WILL TAKE AN EXIT QUIZ !!!

More Related