Textbook resources • pp. 517-522 • pp. 527-8 Animal Diversity • p. 530 part 2 • pp. 531-2 Clicker question In protostomes A. The blastopore becomes the mouth. B. The blastopore becomes the anus. C. Development involves indeterminate cleavage. D. B and C Fig. 25.2 Phylogeny to know (1). Symmetry Critical innovations to insert: Oral bilateral symmetry ecdysis mouth develops after anus multicellularity Aboral tissues 1 Animal diversity, part 2 Parazoa Diversity 2 I. Parazoa • Porifera: Sponges II. Cnidaria & Ctenophora • Tissues • Symmetry I. Outline the • Germ Layers III. Lophotrochozoa unique • Embryonic characteristics Development of sponges IV. Ecdysozoa • Body Cavities • Segmentation Parazoa Parazoa • Porifera: Sponges • Porifera: Sponges – Multicellular without – Hermaphrodites tissues – Sexual and asexual reproduction – Choanocytes (collar cells) use flagella to move water and nutrients into pores – Intracellular digestion Fig. 25.11 Animal diversity, part 2 Clicker Question Diversity 2 I. Parazoa In diploblastic animals, the inner lining of the digestive cavity or tract is derived from II. Cnidaria & Ctenophora A. Endoderm. II. Outline the B. Ectoderm. unique III. Lophotrochozoa C. Mesoderm. characteristics D. Coelom. of cnidarians and IV. Ecdysozoa ctenophores 2 Coral Box jelly Cnidaria and Ctenophora • Cnidarians – Coral; sea anemone; jellyfish; hydra; box jellies • Ctenophores – Comb jellies Sea anemone Jellyfish Hydra Comb jelly Cnidaria and Ctenophora Fig. 25.12 Coral Box jelly Cnidaria and Ctenophora • Tissues Fig. 25.12 – Ectoderm and endoderm; connected by mesoglea • Symmetry – Radial Sea anemone Jellyfish Hydra 3 Cnidaria Cnidaria • Body Cavities Fig. 25.12 • Nerve nets – Gastrovascular cavity • Sexual and asexual for extracellular reproduction digestion • Cnidocytes – Stinging cells – Prey immobilization – Predator injury Fig. 25.13 Ctenophora Ctenophora Mouth • Body Cavities • Nerve nets – Gastrovascular cavity • 8 rows of cilia for extracellular – Largest animals using digestion cilia for movement – Complete gut Stomach • Hermaphrodites • Mouth and anus • Bioluminescence Anal pore Animal diversity, part 2 Clicker Question Diversity 2 I. Parazoa Cnidarians defend themselves using A. A nerve net. II. Cnidaria & Ctenophora B. Bioluminescence. III. Describe the C. Nematocysts. distinguishing III. Lophotrochozoa D. Choanocytes features of two types of lophotrochozoans IV. Ecdysozoa 4 Lophotrochozoa Lophotrochozoa • Diverse clade • Lophophore: crown of ciliated tentacles • Trochophore: distinct larval stage with band of cilia Fig. 25.2 Lophotrochozoa: Platyhelminthes Lophotrochozoa: Platyhelminthes • Flatworms • Flatworms • Triploblastic – Cephalization Fig. 25.15 • Body Cavities –Nerve net, but – Acoelomate beginnings of – Incomplete digestive centralized tract with only one nervous system opening • Cerebral ganglia/ lateral nerve cords Lophotrochozoa: Platyhelminthes Clicker Question • Flatworms Flatworms lack a coelom, but are grouped in the – Hermaphrodites Lophotrochozoa, all the other members of which do have a coelom. This suggest that in the – Sexual or asexual reproduction past, flatworms… – Many are parasites A. Never had a coelom. B. Had a coelom but then lost it. Fig. 25.17 5 Animal diversity, part 2 Lophotrochozoa Diversity 2 I. Parazoa II. Cnidaria & Ctenophora III. Describe the distinguishing III. Lophotrochozoa features of two types of lophotrochozoans IV. Ecdysozoa Fig. 25.2 Lophotrochozoa: Annelida Lophotrochozoa: Annelida • Segmented Worms • Setae • Segmented Worms • Double transport • Parapodia system – Closed Circulatory system – Coelomic fluid • Ventral nerve cord – Pair of cerebral ganglia – Giant axons • Primarily sexual reproduction Fig. 25.22 Animal diversity, part 2 Clicker question Diversity 2 I. Parazoa Which is the correct hierarchy of divisions in the animal kingdom, from most inclusive to least inclusive? II. Cnidaria & Ctenophora A. Radiata, Eumetazoa, Protostomia, Ecdysozoa IV. Describe the B. Parazoa, Radiata, Lophotrochozoa, distinguishing III. Lophotrochozoa Deuterostomia. features of one C. Eumetazoa, Bilateria, Protostomia, types of Ecdysozoa. ecdysozoan IV. Ecdysozoa D. Parazoa, Bilateria, Protostomia, Ecdysozoa. 6 Ecdysozoa Ecdysozoa • Cuticle – Nonliving exoskeleton – Support – Protection • Ecdysis – Periodic molting of exoskeleton Fig. 25.2 Spider Ecdysozoa: Arthropoda • Jointed appendages • Spiders Millipede Centipede • Millipedes & centipedes • Insects • Crustaceans Insect Crustacean Ecdysozoa: Arthropoda Ecdysozoa: Arthropoda • Thick cuticle prevents gas exchange • Segmentation with • Tracheal system specialization • – Spiracles Fusion of segments into tagmata – Trachea – Head – Thorax – Abdomen • Extensive cephalization Fig. 25.26 – Sense organs 7.