Invertebrate Diversity Comparison of Increasing Complexity

Remember: What are the levels of classification? 2. What are the body systems? 3. What organs are in your cranial cavity? - thoracic cavity? - abdominal cavity?

Kingdom Animalia Invertebrata Phyla: Porifera -sponges Cnidaria-sea anemones, coral and jelly fish Platyhelminthes-planaria, flukes, tapeworms Nematoda -roundworms

Mollusca-snails, seashell animals, octopii and squid Annelida - earthworms & leeches Mollusca-snails, seashell animals, octopii and squid Arthropoda – Insects, Arachnids, Crustaceans, Echinodermata – Starfish, Sand dollars, sea urchins

Porifera Sponges spongin- protein fibers spicules for skeleton individual cells acting together as an organism filter water for food asexual or sexual reproduction (hermaphrodite)

Cnideria Jellyfish and corals Radial symmetry Cnidocytes - stinging barbs to capture prey polyp to medusa asexual or sexual

Phylum Nematoda Roundworms - hydrostatic skeleton - parasitic worms                                                                                                                                

Phylum Platyhelminthes Flatworms-tapeworms, Planaria, flukes - bilateral symmetry - Ganglia Cells (anterior)

Class cestoda Tapeworms Parasites Attach to intestinal wall of host with scolex Individual proglottids absorb nutrition from host –don’t need digestive system

Mollusca Octopii, Squid, Clams, Snails Have “cephalization” -a region at the anterior end where well developed sensory organs are located Open Circulatory system (not real vessels) Well developed Digestive system Reproduce sexually Octopii, Squid, Clams, Snails

E A R T H W O M S ANNELIDA & LEECHES

External Anatomy Clitellum - the wider, raised portion of the worm toward the anterior (head) end. Setae- movement

Segmentation Both Mollusks and Annelids have body plans with distinct regions, but in Annelids, these regions are separated by tissue to form true segments.

How are HUMAN BEINGS separated into body segments? Brain in head Heart & Lungs in Thorax Digestive and Reproductive organs below diaphragm

Arthropods * largest and most diverse phyla * segmented bodies, jointed appendages, exoskeleton * complex muscular system, ventral nerve cord & brain, open circulatory system. * includes insects, crustaceans, spiders

ECHINODERMS * Only live in salt water (oceans) * They have rays or long, tapering arms. * Hard, bumpy, spiny skeleton * Tube feet that aid them in movement, exchanges gases, capture food and excrete waste. Ex: starfish, sand dollar, sea cucumber, sea urchin