Phylum PoriferaPhylum Annelida - sponges- segmented worms Phylum CnidariaPhylum Molluska - jellyfish, corals- snails, clams, squid Phylum NematodaPhylum Arthropoda - roundworms- insects, spiders Phylum PlatyhelminthesPhylum Echinodermata - flatworms- starfish

Radial Symmetry - any number of imaginary planes drawn through organism dividing it into equal halves Bilateral Symmetry - imaginary plane divides body into right and left sides (mirror images) Asymmetry - no symmetry

Types of Symmetry

-Multicellular and aquatic - no body symmetry - filter feeders (heterotrophic) - lack cell walls and true tissues - internal skeletons made of spongin and/or spicules of calcium carbonate or silica - contain choanocytes that help move water into the internal chamber species

Class Demospongiae (90% of all living sponges) - typical sponges - bath sponges, tube sponges, yellow sponge Class Hexactinellida - Glass sponges Class Calcarea - calcareous sponges

9000+ species - Carnivorous and aquatic - Radial symmetry - lack internal transport of nutrients - respiration through body wall (diffusion) - contain nerve net - contain specialized cells called cnidocytes, used to capture prey

Two major forms: Polyp Medusa

Cnidocyte w/ nematocyst Sea Anemone Eating

Class Hydrozoa - Hydras Class Anthozoa - corals, sea anemones Class Scyphozoa - jellyfishes

Box Jellyfish Irukandji

- Soft bodies with muscular foot - bilateral symmetry - hard shells for protection - two openings for digestion - respiration through gills or mantle cavity - complexity of nervous system varies - open circulation (cephalopods are closed cir.) - free-swimming trochophore larval stage 50, ,000 sp.

Class Bivalvia - clams, oysters, mussels - aquatic

Class Gastropoda - snails, slugs - aquatic or terrestrial - chambered shell w/ radula Radula

Class Cephalopoda - squid, octopus, nautilis - complex nervous system Blue-ringed octopus

- Radial symmetry - tube feet work w/ endoskeleton for movement - water vascular system - respiration via surface of tube feet or skin gills - nerve ring connects each body segment sp. Sea Urchins and Predatory Sea Star

Class Crinoidea - Sea lily, feather star Class Asteroidea - Sea stars

Class Ophiuroidea - Brittle star, basket star Class Echinoidea - Sand dollars, sea urchins Class Holothuroidea - Sea cucumbers

- One way digestion (mouth and anus) - gas exchange through body walls - circulation by diffusion - some free-living, others are parasitic (may live anywhere!!) - simple nervous system (ganglia and nerves) - separate sexes (male and female) 15,000+ species C. elegans Roundworms

Research on C. elegans first organism to have DNA completely sequenced It is a very simple, free living roundworm

Ascaris lumbricoides pinworm Hookworm

Digestive tract with 2 openings: mouth & anus Feeding Free-living - predators Parasites - humans and animals Reproduction: Sexual reproduction, Separate sexes (male & female)

Ascarid Worms (common roundworm) - lives in intestine - eggs are passed out in the feces Most roundworms infect dogs, but occasionally they find their way into human hosts

Roundworms & Disease Trichinosis (trichinella worm) - cysts within the muscles are consumed (undercooked food) -- worm grows in intestine -- forms cysts in the muscles of the new host -- symptom: terrible pain in muscles

Hookworms - burrow into the skin from soil - mature in the intestines --hooks used to attach and suck blood

Filarial Worms - found in Tropical regions of Asia -- usually transmitted by mosquitoes -- causes elephantiasis

- Bilateral symmetry - cephalized; several ganglia w/ nerve cords - circulation and respiration via diffusion - nephridia excrete wast - free-living predators or parasites that feed on blood and body fluids - most hermaphroditic or reproduce asexually 20,000+ sp. Flatworms

Class Turbellaria - planarians

Class Trematoda - liver flukes, Schistosoma Liver fluke life cycle Intermediate host Final host

Flukes: live in mouth, skin, or gills of host Primary host = the host in which a parasite reproduces sexually Intermediate host = the host in which asexual reproduction occurs

Schistosoma mansoni - multiple host: Primary host = human Intermediate host = snail Causes Schistosomiasis -in humans; decays lungs liver, spleen, or intestines, occurs in tropical areas with poor sanitation/sewage.

Class Cestoda - tapeworms - each proglottid contains male and female reproductive organs - break off into feces w/ fertilized eggs

Scolex = a structure that contains suckers and/or hooks Proglottids = body segments of the tapeworm

Tapeworm Life Cycle

Sometimes, a dormant, protective cyst is formed in the intermediate host muscles ****This is why you should never eat incompletely cooked meat.

15,000+ sp. - bilateral symmetry - segmentation!! - closed circulation - respiration via gills (aquatic) or skin (terrestrial) - simple brain and nerve cords - one way digestion (mouth to anus) - most have sexual reproduction - nephridia used for excretion

Annelida means “little rings” -setae used for movement through soil (terrestrial worms)

Class Hirudinea - leeches Medical leech used to drain excess blood from patients

Leeches being bred for medical uses.

Class Polychaeta - fanworms, bloodworms, fireworms - aquatic bloodworm fireworm fanworm

Class Oligochaeta - Earthworms - live in soil or freshwater - use setae for movement - clitellum houses reproductive organs clitellum

Castings - enrich soil, (worm poop)

- Bilateral symmetry and segemented - cephalized; dorsal nerve cord w/ ganglia - chitinous exoskeleton - jointed appendages - respiration via tracheal tubes, book lungs, or gills - open circulatory system - malphigian tubules for excretion - simple and compound eyes 1,000,000+ sp.

Class Insecta - dragonflies, grasshopper, beetles Class Diplopoda - Millipedes Class Chilopoda - Centipedes

Class Crustacea - crabs, crayfish, barnacles Class Arachnida - spiders, scorpions Class Merostomata - Horseshoe crabs

Class Arachnida Ticks & Mites Many parasitic No segmentation

Scorpions Common in deserts Most nocturnal Large pincers & large stinger UV light - glow

Spiders Most common arachnid Cephalothorax & Abdomen Fangs – all have venom Silk – but not all build webs Beneficial for humans

Most live 1-2 years but Tarantulas up to 30 Most have 8-12 eyes Largest = 10” leg span Goliath Bird-Eating Spider

Illinois Dangerous Spiders Black Widow (female) Brown Recluse (Violin Spider) 3 sets of eyes