1. Invertebrates BIOZ 341 Dr, Rafat Khattab Biology Department E-mail: rafifi2001@hotmail.com

2. Invertebrate Zoology Study of invertebrate animals Inverts make up at least 99% of all extant (living) animal species on the planet Over 1,000,000 described spp. (species) on the planet (mostly insects) Estimated 10 to 30 million spp. have yet to be described We will cover 19 (time permitting) of the approx. 35 animal phyla

3. Invertebrates Invertebrates are those animals without backbone. They can be classified into several taxa according to several criteria: 1- Presence or absence of proper tissues, 2- Number of layers of tissues present 3- Presence or absence of body cavity.

4. Invertebrates include protists, parazoans and metazoans orgamnisms Protista; which includes Protozoa and other single celled organisms Parazoa are those multicellular animals, which lack proper tissues. Animals belong to Phylum Porifera (sponges) are good representatives to Parazoa. Metazoa are those multicellular animals, which have proper tissues.

5. Phylum Coelentrata (Cnidaria) includes diploblastic (two layered) metazoans. Acoelomates are triploblastic (three layered) metazoans without a body cavity (solid bodied invertebrates), such as Phylum Platyhelminthes. Pseudocoelomates are triploblastic metazoans with a pseudocoelom (the cavity originated from the blastocoel), such as Phylum Aschelminthes.

6. Coelomates are triploblastic metazoans with true coelom (the cavity originated from the mesoderm). These include annelids (segmented worms), arthropods (jointed legs invertebrates), molluscs (soft bodied invertebrates), echinoderms (spined skin invertebrates), and chordates (animals with a notochord). This course deals with the study of taxonomy, morphology, and biology of some major examples representing Protozoa, Parazoa, lower and some higher Metazoa of invertebrates.

7. Exploring invertebrate diversity PORIFERA (5,500 species) A sponge CNIDARIA (10,000 species) A jelly PLACOZOA (1 species)KINORHYNCHA (150 species) 0.5 mm A placozoan (LM) A kinorhynch (LM) 250 µm PLATYHELMINTHES (20,000 species) ROTIFERA (1,800 species) A marine flatworm A rotifer (LM) ECTOPROCTA (4,500 species) PHORONIDA (20 species) Ectoprocts Phoronids Figure 33.3

8. Exploring invertebrate diversity BRACHIOPODA (335 species) NEMERTEA (900 species) A brachiopod A ribbon worm ACANTHOCEPHALA (1,100 species) CTENOPHORA (100 species) An acanthocephalanA ctenophore, or comb jelly MOLLUSCA (93,000 species)ANNELIDA (16,500 species) An octopus A marine annelid LORICIFERA (10 species) PRIAPULA (16 species) 5 mm 50 µm A loriciferan (LM) A priapulan Figure 33.3

9. Exploring invertebrate diversity NEMATODA (25,000 species) ARTHROPODA (1,000,000 + species) A roundworm A scorpion (an arachnid) CYCLIOPHORA (1 species) TARDIGRADA (800 species) 100 µm A cycliophoran (colorized SEM)Tardigrades (colorized SEM) ONYCHOPHORA (110 species) HEMICHORDATA (85 species) An onychophoran An acorn worm ECHINODERMATA (7,000 species)CHORDATA (52,000 species) A sea urchin A tunicate Figure 33.3

10. Preview of Phyla We Will Cover Protozoa – animal-like protists Do not belong to kingdom animalia, and thus are not considered to be invertebrate animals Important evolutionary link between prokaryotes, and everyday plants and animals Volvox

11. Phylum Porifera Sponges

12. Phylum Cnidaria Jellyfish, Anemones, and Corals Portuguese Man O’ War

13. Phylum Ctenophora Comb Jellies

14. Phylum Platyhelminthes Flatworms

15. Phylum Nemertea Ribbon Worms

16. Phylum Mollusca Chitons, Clams, Snails, Slugs, Squids, and Octopi Banana Slug

17. Phylum Annelida Segmented Worms

18. Phylum Echiura Spoonworms

19. Phylum Sipuncula Peanut Worms

20. Phylum Tardigrada Water Bears

21. Phylum Arthropoda Horseshoe Crabs, Arachnids, Crustaceans, Myriapods, and Insects

22. Phylum Gastrotricha Name means “stomach hair”

23. Phylum Nematoda Roundworms Caenorhabditis elegans = good Ascaris lumbricoides = bad

24. Phylum Rotifera Wheel bearers

25. Phylum Phoronida A lophophorate

26. Phylum Brachiopoda Lamp shells, another lophophorate

27. Phylum Bryozoa Bryozoans, the largest phylum in the superphylum Lophophorata

28. Phylum Echinodermata Starfish, Brittle Stars, Urchins, and Sea Cucumbers

29. Phylum Chordata Phylum Chordata is the only phylum containing vertebrate animals, however, there are some invertebrate chordates