1 / 18

Parazoa and Radiata

Parazoa and Radiata. Sponges Cnidarians Ctenophores. Phylum Porifera: The Sponges. General Information. Mainly marine organisms; evolved from choanoflagellates May have algae or bacteria that give them color Larva are flagellated, adults considered sessile

kiri
Download Presentation

Parazoa and Radiata

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. Parazoa and Radiata Sponges Cnidarians Ctenophores

  2. Phylum Porifera: The Sponges

  3. General Information • Mainly marine organisms; evolved from choanoflagellates • May have algae or bacteria that give them color • Larva are flagellated, adults considered sessile • Many disease-fighting compounds holdfast

  4. Tube Sponges Encrusting Sponges

  5. Characteristics • Can reproduce sexually or asexually • Gas exchange and excretion - diffusion at individual cells • Supported by skeletal fibers: spicules or spongin • Simple animals made of few specialized cells; NOtissues • Asymmetrical • Body with ostia • Most are filter feeders / suspension feeders • 1 family is carnivorous

  6. Anatomy of a Sponge: • Osculum • Spongocoel • Choanocyte • Amoebocyte • Mesohyl

  7. Suspension Feeding & Gas Exchange

  8. Sponge Reproduction: • Asexual reproduction • Buds or gemmules • Sexually – most sponges are hermaphrodites • Cells become egg/sperm • Sperm released into water • Fertilization occurs in mesohyl (egg) • Zygote becomes flagellated larva that leaves in flow of water

  9. Phylum Cnidaria Jellyfish Box jelly Sea anemone Coral

  10. Main Characteristics • Diploblastic, radial symmetry • Cnidocytes with nematocysts concentrated in tentacles • Gastrovascular cavity with 1 opening • 2 layers separated by mesoglea • Gas exchange and excretion occur by diffusion

  11. Structure cont… • Nerve nets • Connect sensory cells to contractile cells • Sense organs around edge of body • Ex. photoreceptors • Contractile cells • Not true muscles • Act as hydrostatic skeleton

  12. Cnidarians come in 2 forms: • Medusa – tentacles down • Polyp – tentacles up Many alternate between medusa and polyp during life cycle

  13. Hydrozoa ScyphozoaCubozaAnthozoa 4 Classes of Cnidaria

  14. Cnidarians are Carnivores • Feed on fish, larva, comb jellies, other zooplankton • Sting prey with their tentacles • Mouth  gastrovascular cavity  mouth • Jellyfish.asf

  15. Many have symbiotic zooxanthellae Environmental issue: Coral Bleaching A word about corals:

  16. Interesting Facts… Portuguese Man-of-War • Colonial • Has sail-like float • Tentacles can grow up to 165 feet and are nearly invisible

  17. More interesting facts… Box Jellies • More toxic than Man-of-War • Stings can lead to heart failure within minutes • Tentacles may reach 15 feet

  18. CTENOPHORA: THE COMB JELLIES • Diploblastic??; Biradial Symmetry • Swim with 8 rows of ciliary combs • Have 2 long tentacles with sticky cells • Colloblasts • Eat large amounts of fish larva & plankton • Mouth + 2 anal pores • Introduced/Invasive species (Black Sea)

More Related