Chapter 33 Invertebrates 09 24 2015 Kingdom Animalia Subkingdom Parazoa Phylum Porifera Sponges Means to bear pores 600 mya came about Azure vase sponge a very common sponge Haven t changed a lot in 600 million years Fossilized sponges are much like sponges we have today Have cells but don t have tissues Can breakup a sponge through cheese cloth because they don t have tissues they can go back together Asymmetrical has no symmetry They are like a sack No digestive system No nervous system No circulatory system Amoebocytes wander around the inside Three layers to the cell wall o Sponges don t gastrulate o Epidermis o Inner layer lined with Choanocytes Choanocytes cells that collect food for the sponge o Mesohyl is the inner layer o Sponges are filter suspension feeders They pull water into their holes and things in the water get trapped in the choanocytes where they are then digested Spicules used to classify sponges gives them some support o Made up of silica o Can be calcium carbonate o Can be a collagen type material Each cell of a sponge can react because they don t have nervous systems Sponges are sessile Some have a toxin in them that prevents fish from eating them Can reproduce sexually and asexually o Asexually by budding Most sponges are hermaphrodites produce both sperm and eggs Sequential hermaphrodites change sex during lifetime start as on and finish as the other Releases sperm out osculum Sperm sucked in different sponge through pores fertilization occurs inside Ciliated larva released through osculum to go find a place to live and grow Phylum Cnidaria Sea nettle Will sting you Used to be called coelenterates Dipoplastic o Have epidermis o Yellow lining called gastrodermis o Mesoglea inner tissue o Gastrovascular cavity in the middle acts as gut and vascular system o Tentacles surrounding the mouth anus Very thin walls Diffusion of food and water through walls sessile Polyp stage mouth up Medusa stage mouth down both stages are diploid food in through mouth gastrodermis sends out enzymes garbage back out the way it came in cnidocyte ell contains nematocyst o line all of the tentacles o contains trigger o when trigger is hit the thread discharges and barbs latch to the cuticle of the prey Jellyfish have these Classes of Cnidaria o Hydrozoa Portugese man of war Don t age Most marine few freshwater Main stage is polyp stage Usually colonial lives around each other Know the life cycle Only haploid stage is the sperm and egg They are having an orgy o Scyphozoa Jellies jellyfish sea nettles All marine polyp stage absent or reduce no muscle system but cells can contract no controlled movement medusa form is main stage o Cuboza Box jellies sea wasps All marine Box shaped Most potent creatures in the world 1 sea wasp poison can kill 60 people turtles can eat them and it doesn t affect them sperm and egg form zygote that will form directly into a medusa skipping the polyp stage o Anthozoa Seas anemones most coral sea fans All marine Medusa stage completely absent Most colonial Toxic tentacles symbiotic relationship with some fish Corals takes calcium from the water to make calcium carbonate their house Phylum Ctenophora Comb jellies Largest animal to move by cilia Radial symmetry Has 8 comb rows how it got the name cone jelly They glow Has tissue level organization Catch their prey with tentacles that have a glue like substance on them that animals get stuck to Acoelomates Phylum Platyhelminthes Helmenthy worm like Platy flat Flatworms Bilateral symmetry Has better movement Warning colors bright reds organs telling predators it is bad Extracellular and intracellular digestion No circulatory or respiratory sytem Has mesoderm 3 germ layers Have a gastrovascular cavity that is branched o Has more surface area Classes o Turbellaira Includes planaria predator lay down in freshwater and senses things moving over him and attacks based on shadow size Mostly free living Triangular shaped head Has eyespots light sensitive regions determines which side is the head Ventral nerve cords communication between left and right side of the body Form ganglia processing unit of connecting nerve cell bodies Pharynx extended out of digestive system Uses to suck food in and eat it Capable of primitive learning Has an excretory system called flame cell protonephia Lives in freshwater Cilia used to draw water out so that it won t burst Most are hempharodidic If you don t feed them they eat themselves and get smaller and smaller until they are just kind of gone They can regenerate have two heads Can teach them to run places o Trematoda Live on fish and turtles Same color as the turtles sink Flukes Parasites of vertebrates mostly Very involved life cycle Internal parasites Male and female become like one organism Freshwater snails are hosts can lead to human being a host blood fluke lays eggs in intestines some flukes get into snails and control their brains and antenna movement so that they can use birds to carry out their life cycles o Cestoda Tape worm Schistosoma deadly disease Suckers and hooks in tape worm used to hook onto intestine Scolex head with suckers and hooks Proglottids packs of sperm and eggs One packet can contain 8 000 100 000 eggs Can have up to 2 000 segments Release these packets through intestines Pseudocoelomates Many worm like looking Body not completely lined with mesoderm Use as a hydrostatic skeleton Phylum Rotifera Creatures called rotifers Has a mouth and anus Cell constant animals all have exactly the same number of cells Once they go through embryonic development they can t do mitosis anymore Once a cell is lost it is gone forever Parthenogenesis virgin birth eggs develop without being fertilized by sperm Multicellular When the environment changes they begin to produce males which then allows for sexual reproduction and genetic diversity Phylum Nematoda Round worms Can have fluid in pseudocoelom o Acts as a hydrostatic skeleton o Gives them better movement Have mesoderm Have longitudinal muscles not circular ones Some of them are free living and some are parasites Very bad when it comes to our plants Cause a bunch of diseases in humans 50 species of these are parasitic to humans Trichinella Spiralis causes Trichinosis o Carried in pork o The worms live in the pig intestine and gets into the muscle o In the muscle they form cysts and there can be 10 000 o Digestive juices liberate the worms and can travel into human muscles and creates cysts causes pain and anemia and