Create your own animal?What is an animal?Animal PhylaSome animals alternate generationsDevelopment and EvolutionAnimalsAnimals evolved from Choanoflagellate AncestorsCampbell Fig. 18.3 DPoriferaChoanocyte of a SpongeCampbell 18.3CMain Cell TypesCampbell 18.3CSponges exhibit radial symmetryOther Sponge Body FormsSpiculesPhylum CnidariaCnidariansMajor CharacteristicsTwo Types of BodiesCampbell Fig. 18.4 A-CTissue layers and gastrovascular cavityCnidocyteCampbell Fig. 18.4 DPop QuizPhylum PlatyhelminthesBilateral Body DesignSimplest Bilateral AnimalsSchistosome Fluke Life CycleCampbell Fig. 18.6BTapeworm Adult Anatomycompare Campbell 18.6Eucoelomate Body Designcompare CampbellFig. 18.7CMost animals have a body cavityThe Evolution of Animal DiversityDr. Stephen J. SalekBiology 130Fayetteville State UniversityCreate your own animal?• Start with a basic plant. Make the plant into a simple animal such as a worm. Consider:• Body form, cell types, feeding, reproduction, movement, lifespan, size, growth, developmentWhat is an animal?• Multicellular, ingestive heterotrophswithout cell walls• Many have flagella and cilia• Have unique intercellular junctions• Digestion in an internal space or tract• Dominant diploid phase• Unique embryonic phases sometimes including larvaAnimal PhylaExample•Sponges•Jellyfish•Flatworms•Roundworms• Segmented worms• Crabs, insects• Snails, squid, clams•Starfish, sand dollars• Mammals, birds etc.Phyla• Porifora•Cnidaria• Platyhelminthes•Nematoda•Annelida•Arthropoda•Mollusca•Echinodermata•ChordataSome animals alternate generations• Diploid adult is dominant• Sperm or eggs produced by meiosisCampbell 18.1Development and EvolutionCampbell 18.2• Animals go through stages of development• Zygote - blastula - gastrula- larvaeAnimals• Digest food inside multicellularbodies• Composed of diploid cells except gametesAnimals evolved fromChoanoflagellate AncestorsCampbell Fig. 18.3 D• nucleic acids match•large colonies of choanoflagellates, turned outside-in, wouldresemble spongessmall choanoflagellate colonyPoriferaSponges, the SimplestAnimal DesignChoanocyte of a SpongeCampbell 18.3C• Sponges are simple multicellular animals• Have porous bodies• Filter feed using chonaocytes and phagocytosisMain Cell TypesCampbell 18.3C •Choanocytes-create water flow and trap food• Amoebocytes- pick up food, digest it, carry it to other cellsSponges exhibit radial symmetry• Radial symmetry-– Mirror images around a central axis– Campbell 18.3BOther Sponge Body FormsSpicules• mineral needles• may be calcium carbonate or silica (glass)• for skeletal support and defensePhylum CnidariaRadially symmetrical animals that stingCnidariansMajor Characteristics• Radial symmetry• Have two body types and a larval form– Polyp, medusa, and planula body forms• Two tissue layers– epidermis and gastrodermis, • Incomplete gut - “gastrovascular cavity”• Cnidocytes - stinging cellsTwo Types of BodiesCampbell Fig. 18.4 A-Cpolyp(attached, mouth-up)medusa(free-drifting, mouth-down)Tissue layers and gastrovascular cavityfood in gastro-vascular cavitycnidocytesgastrodermisepidermisCnidocyteCampbell Fig. 18.4 Dcnidocil ortriggernucleusPop Quiz• List 3 distinguishing characteristics of the following two animal phya•A) Porifera• B) CnidariaPhylum PlatyhelminthesFlatworms - the Simplest Bilateral AnimalsBilateral Body Design• cephalized– sensory organs concentrated in head•body directions:Simplest Bilateral Animals•Move through environment headfirst not drifting like radial symmetric animals• Gastrovascular cavity• Free living, parasitic flukes, tapewormsCampbell 18.6ASchistosomeFluke Life CycleCampbell Fig. 18.6Badults(unusual because diecious)miracidiumcercariasporocystreproduces asexuallyeggsTapeworm Adult Anatomycompare Campbell 18.6Scolex -anchors worm,buds asexuallyProglottid -reproduces sexuallytestesuterusovariesgonoporeGravid Proglottids -break off and release eggsacoelomatepseudocoelomateeucoelomate(muscles, not peritoneum)peritoneumEucoelomateBody Designcompare CampbellFig. 18.7CendodermmesodermectodermCoelom: fluid-filled cavity between gut and body wall that is lined with mesodermalcells (peritoneum).Most animals have a body cavity• Solid, no body cavity except for gastro vascular cavity flatworms, cnidaria• Pseudocoelomate-internal space in contact with digestive tract, roundworms• True coelom - internal space lined by tissue -all other