Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Porifera and Cnidaria Chapter 26.1 and 26.2 Animal Classification Invertebrates .Sponges Cnidarians Worms Mollusks Arthropods Echinoderms Phylum Porifera Animals (cold-blooded) Fishes Amphibians Reptiles Endotherms Birds Mammals Ectotherms Vertebrates (warm-blooded) Kingdom: Animalia Phylum: Porifera More than 5000 species have been identified Most are found in marine biomes (salt water) Around 150 species are found in freshwater Characteristics Asymmetrical The first multicellular organism Sponges are consisted of groups of cells No respiratory, excretory or nervous systems Characteristics Filter feeders Some species can be torn apart and reassemble itself Anatomy of the Sponge Pore cell – allows water carrying food and oxygen into the sponge Epithelial-like cells – control what goes in the sponge by closing pores Osculum – Water and waste are expelled through this structure Pore cell Collar cell Epithelial-like cells Anatomy of the Sponge Collar cell – has a flagellum that moves water into the cell Spicules – small, needlelike structures that give sponges support Ameobocytes – carry nutrients, aid in reproduction, and help produce spicules Collar cell Anatomy of the Sponge Collar cell Food is broken down at the amebocyte Asexual Reproduction in Sponges Budding – an external growth forms on a sponge Sponge colonies are formed by budding Fragmentation – a part of a sponge breaks off and grows into a new sponge Sexual Reproduction of Sponges Some sponges have one sex Most sponges are hermaphrodites – animals that can produce both sperm and eggs Fertilization can be external or internal sperm Fertilizes to form larva Larva attaches to a surface Sponge releases sperm egg Sponge releases egg A new sponge develops Support and Defense Systems in Sponges Spicules gives sponges support Some sponges contain chemicals that are toxic to fishes Animal Classification Invertebrates Sponges Cnidarians Worms Mollusks Arthropods Enchinoderms Phylum Cnidaria Jellyfish Hydra Coral Sea anemone Animals (cold-blooded) Fishes Amphibians Reptiles Endotherms Birds Mammals Ectotherms Vertebrates (warm-blooded) Kingdom: Animalia Phylum: Cnidaria Cnidarians consist of 9000 species of jellyfishes, corals, sea anemones, and hydras Most cnidarians are found in marine biomes Sea anemone Corals Hydra Characteristics Radial symmetrical One body opening The mouth is also the anus Two Body Forms Polyps Familiar body form of hydras Sessile Tentacles and mouth/anus face up Reproduces asexually by budding Two Body Forms Medusa Familiar body form of jellyfishes Mobile Tentacles and mouth/anus hang down Reproduces sexually using sperm and eggs Reproduction in Cnidarians Cnidarians can reproduce sexually and asexually Sexual Reproduction Blastula Larva Medusa breaks away Asexual Reproduction Reproduce by budding Polyp Attach to surface Digestion in Cnidarians Cnidocyte – stinging cells located at the tips of the tentacles Digestion in Cnidarians Nematocyst – a small barbed harpoon used for defense and to spear prey The nematocysts discharge when prey touches the tentacles Nematocysts inject prey smooth (like a knife) and flare out (like barb wire) Digestion in Cnidarians Gastrovascular cavity – digestive enzymes are released over captured prey in this space Undigested materials are ejected out of the mouth Nervous System in Cnidarians Nerve net – conducts impulses to and from all parts of the body A simple nervous system