Lecture 17 1 Describe the general synapmorphies of animals 2 Describe characteristics that are used to describe individual animal phyla 3 Describe the general characteristics of sponges jelly fish and lophotrochozoan invertebrates 4 Explain the feeding mechanisms used by sponges and jelly fish 5 Characterize the groups of lophotrochozoans 6 Describe the general characteristics of mollusks and segmented worms the features that account for their divertsity and the different classes Genetic and morphological traits are animal synapomorphies Animals ancestors were like choanoflagellates Flagella In opisthokonts Single and posterior if present Sponges are early animals What are the characteristics of animals Characteristics are not synapomorphies Multicellular Heterotrophic Internal digestion Movement Some only move in larval stages Collagen proteoglycan Extracellular matrix Strengthens outside of cell Intracellular junctions Tight junctions Used for absorption Found in intestine stomach Desmosomes Used to anchor and connect Found in skin Gap junctions Used for fast communication Found in nervous tissue Synapomorphies are found in DNA Animals are monophyletic How the cell divides depends on the amount of yolk present and how the yolk divides Tissue layer for through cell specialization Skin glands brain Animals are monophyletic and diverse Sponges Eumetazoans Diploblastic animals 2 germ layers Bilaterians Triploblastic 3 germ layers Animal groups are defined by developmental patterns Cleavage Incomplete Radial Spiral Diploblastic Ectoderm Endoderm Gut Triploblastic Mesoderm Muscles Organ systems Protostome Form mouth first Deuterostome Form mouth second anus first Body cavities form differently among groups Gastrulation Blastopore Protostome Forming of the primitive gut Becomes mouth or anus Can be diplo or triplo blastic Deuterostome Animal body plans are usually symmetrical Asymmetrical No symmetry Radial symmetry Can cut organism into multiple plains to get mirror images Penta radial Echinoderms Larva are bilateral Ex Sea anemone Cnidarianss Bilateral symmetry One cut to get mirror images in half Ex Frog Human Body cavities influence movement Acoelomate Not hollow Has a mesenchyme layer Move by beating cilia Pseudocoelomate Smal fluid filled spaces One layer of muscle for movement Coelomate True gut Two muscle layers Muscle lined on both sides of cavity Hydrostatic skeleton Septum separating each segment Fluid filled spaces they can use to move and contact In soft bodied coelomates Segmentation allows for specialization of body regions Addition of appendages Can lose an appendage has no effect on organism Diversity of function Exact control of each segment Modified appendages For feeding movement poison glands Rely on environment move water around themselves Animals feed in a variety of ways Filter feeding Herbivores Eat only plants Predators Capture and eat other animals Omnivores Both plants and animals Live within other organisms Parasites Detritivores Feed on dead matter Animals have a variety of life cycles Larvae pupae metamorphosis Major difference between newborn and adult Direct development Newborn and adult look very similar Dispersal methods Parasites Multiple hosts Many animals undergo metamorphosis Metamorphosis is a major change in body plan Larvae pupae Dispersal methods KNOW TABLE 31 3 Sponges are loosely organized without tissues Lack symmetry Ostia Mesohyl Spicules Small pores in the sponges that allow water to flow in Layer that contains choanocytes spicules and amoebocytes Used for support Used to categorize sponges Can be made of proteins or silica Choanocytes Collared cells Catch nutrients the sponge needs Amoebocytes Used for feeding and reproduction Produces spicules Sponges rely on water flow for feeding and reproduction Filter feeding Osculum Water flows through and out Ostium A single pore Brings water in Sexual or asexual reproduction Budding Bring in sperm through pores for fertilization Placozoans are asymmetrical diploblastic animals No mouth gut or nervous system Tissues 2 layers Sexual and asexual reproduction Free swimming larvae Ctenophores are radially symmetrical and diploblastic Mesoglea Part of the extracellular matrix Supports hydrostatic skeleton Complete gut Trap prey in adhesive Stick tenticles Sexual reproduction Direct development Comb jellies Similar to cnidarians Move by cilia and use mesoglea Cnidarians are diploblastic carnivores Gastrovascular cavity Incomplete gut Complex lifestyles Two body forms Medusa free swimming Nerve nets Polyp sessile Simple nervous tissue Nematocysts Stinging cells used for feeding Jellyfish and sea anemones Opening to take in food and opening to expel wastes Gut involved in digestion gas exchange and hydrostatic skeleton Also has mesoglea Cnidaria have two body forms Medusa Produce sperm and egg Free swimming Mouth above tentacles Typically the sexual stage Polyp Sessile Budding Can reproduce sexually Asexual reproduction There are at least 3 clades of Cnidarians Protostomes are made up of two clades Bilateral symmetry and triploblastic Brain central nervous system Lophotrochozoans Lophophore or trochophore or both Ecdysozoans All have to molt Includes nematodes Lophophore Ciliated tenticles Used to get food for gas exchange Trochophore Free living larvae Move by beating cilia Triploblastic Bryozoans are colonial and have lophophores Feeding Use lophophore Asexual and sexual reproduction Cells can have differentiation in colony Colonies formed by asexual reproduction Sexual Release sperm and egg into water column Lophotrochozoans have a lohophore trochophore or both Internal fertilization Flatworms are parasitic or free living Acoelomate No space between layers Incomplete gut Bring food in and spit undigested food back out Planaria Hermaphroditic Triploblastic All capable of being pregnant Parasitic flatworms require multiple hosts Modified structures no sensory ogans Scolex Head of the tapeworm Segments Can break off and leave with feces Extensive reproductive organs Full of eggs Segments that break off Proglottids Life cycle Can form cysts anywhere Eyes bones brain Prefer pigs for cysts and humans for worms Will kill if cyst in human Rotifers are triploblastic and bilaterally symmetrical Pseudocoelomate Ability to have hydrostatic skeleton Complete gut Mouth and anus Sexual and asexual reproduction Most reproduce sexually Separate males and females Bdelloid rotifers Only females Reproduce asexually