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Animals sans Backbone

Animals sans Backbone. How are we related??. Introduction . Most (97%) of the amazing life which is located within the oceans, or anywhere else, doesn’t have a backbone! In every class of invertebrate we can find a marine example…convenient, eh?. Summary of Invertebrates. Sponges-sponge

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Animals sans Backbone

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  1. Animals sans Backbone

  2. How are we related??

  3. Introduction • Most (97%) of the amazing life which is located within the oceans, or anywhere else, doesn’t have a backbone! • In every class of invertebrate we can find a marine example…convenient, eh?

  4. Summary of Invertebrates • Sponges-sponge • Cnidarians- “jellyfish” • Comb Jellies- comb jellies • Symmetrical Worms-flat, round, segmented worms • Molluscs-snails, clams, oysters, scallops, octopuses • Arthropods-copepods, shrimp, and lobster • Echinoderms- seastars, brittlestars • Chordates-seasquirts

  5. Sponges • Sponges are really nothing but a loose aggregation of specialized cells. • Of the 6,000 known spp. nearly all are marine. • Amazingly enough, these cells don’t actually form organs, but do serve similar functions, keeping the animal(s) alive. James Fatherree

  6. Porifera-Sponges (the pore bearers) Spicules are like calcium carbonate or silica re-bar for sponges, providing support for a larger congregation.

  7. Sponges • Do they “sits and thinks, or do they just sits??” • Sponges are sessile and remain permanently attached to the substrate they alight upon.

  8. Still, if you carve ‘em up, they come back for more!! It’s more amazing than that. If you mix groups of sponges together, they will usually reorganize into their original groups.

  9. Suspension feeding: natural water purification

  10. Reproduction: Asexual vs. sexual Damage to a sponge can actually promote asexual reproduction, as “parts” can land elsewhere and form new sponges.

  11. Sexual reproduction • Many sponges are • hermaphrodites, containing • male and female reproductive • capabilities, yet do not self- • fertilize. • Tube sponges, such as this • Verongia archeri which is • common in Caribbean waters • use broadcast spawning to • disperse sperm and eggs in • a flurry of activity that is • often coordinated with lunar • cycles.

  12. General Sponge Types Hawaiian encrusting sponge Sclerosponge (CaCO3) Ceratoporella nicholsoni Sponges fall into several basic categories, mostly depending on shape: branching tubular round encrusting glass boring (destructive) Harvested sponges

  13. Cnidarians Sea anemones, jellyfishes, coral, etc.

  14. Cnidarians • Finally, we see a pie that can be sliced! • Cnidarians actually exhibit radial symmetry in which similar body parts can be grouped around a central axis. • Here we also observe a large jump on the evolutionary scale: tissues that perform specific functions.

  15. General Cnidarian Structureand Function Macrorhynchia phillipina • Centrally located mouth • Oral surface (mouth) • Aboral surface (opposite end) • Tentacles • Gut • Nematocysts (cnidae)! • Polyp and Medusa: reproductive • stages Beautiful, but deadly! This colonial hydrozoan still contains cnidae.

  16. Discharged nematocysts, stingingcells used for defense and prey capture, have been the plague of more than fish. Stings from certain jellyfish have resulted in death in a matter of hours, especially for infants.

  17. Carukia barnesi: the badest of the bad! Irukandji syndrome: A sting from this little guy can cause the following: “It begins with a mild sting, followed by severe lower back pain, muscle cramps in arms, legs, stomach and chest. It causes sweating, anxiety, nausea, vomiting, headaches and palpitations, and has also been known to cause cardiac failure.”

  18. Cnidarians 1. Polyp: a sac-like attached stage with a mouth and tentacles (mostly sessile) 2. Medusa: a mobile bell-like upside down polyp (jellyfish).

  19. Cnidarians

  20. Types of Cnidaria Sea fan multiple comb jellies • Cnidaria come in all shapes and sizes. • Hydrozoans- feathey hydroids • Siphonophores- man-o-war • Scyphozoans- large jellyfish • Anthozoan-sea anemones and coral • Most of the animals found within Cnidaria • are all carnivores.

  21. Comb jellies: Ctenophora Similar to cnidarians in most respects. Nearly 100 spp. Contain cilliary combs which assist in prey capture and mobility.

  22. Marine Worms, etc. • Marine worms, and organisms hereafter, kick it up a notch exhibiting bilateral symmetry (just like humans). • Instead of addressing front and back, we’ll discuss anterior, posterior, dorsal and ventral. • We’ll also pick up a CNS! • Bilateral symmetry, and all that goes with it, results in enhanced motion and sophisticated behaviors.

  23. Flatworms: Platyhelminthes • These simple organisms • contain organs and • systems. • Nearly 20,000 spp. exist • The most common are • turbellarians, like this • Pseudoiceros gratus from • the Great Barrier Reef (lower • right.) • About 6,000 spp. are parasitic, ex. • flukes (trematodes) and • tapeworms (cestodes) • (Steve Irwin would be proud • ‘cause “She’s a beauty!”)

  24. Ribbon worms look like tapeworms. However, they exhibit a complete digestive tract and a circulatory system. ~900 spp. exist

  25. Nematode • Roundworm numbers are staggering in the marine world. • Many animals have them. • Some even find there way into fish (which we ingest when we eat sashimi).

  26. Segmented Worms • 20,000 spp. • Known as Annelids • First example of segmentation. • Allows for flexability and excellent burrowing ability.

  27. Fireworm Hermodice carunculata Polycheates-many bristles (setae) ~10,000 spp. Exhibit parapodia Evolution of gills.

  28. Sandworm Nereis

  29. This feather-duster worm, Sabella melanostigma, is a perfect example of beauty, form and function.

  30. Next time… • Gastropods, Molluscs, and Arthropods

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