Phylum Porifera Sponges
Porifera • Sponges • Living on Earth for at least 540 million years • Most sponges live in the ocean • Arctic to the tropics • shallow water to depths of several hundred meters • They are dry sponges were use for • Bathing • Cleaning
Porifera • What is a Sponge? • Sponges are placed in the phylum Porifera (poh-RIF-ur-uh) which means “pore-bearers.” • Sponges have tiny openings, or pores, all over their bodies • Sponges are sessile, meaning that they live their entire adult life • They have irregular symmetry
Porifera • Why are sponges considered animals? • Sponges are multicellular, heterotrophic, have no cell walls and contain only a few specialized cells. Water flow
Porifera: Structure • Specialized cells of sponges: • Collar cells or choanocytes – Use flagella to move a study current of water through the sponge. • Osculum – A large hole at the top of the sponge • Spicule– spike-shaped structure made of chalklike calcium carbonate or glasslike silica • Amoebocyte – move around within the walls of the sponge and carry food to other cells
Porifera: Digestion • Sponges are filter feeders – take microscopic food particles from the water. • As water moves through the sponge, food is trapped and engulfed by collar cells (choanocytes) that line the body cavity • Then, food gets passed to amebocytes who take the food to the rest of the cells in the body
Porifera • How do they breathe? • Sponges rely on the movement of water through their bodies to carry out body functions: • Respiration – oxygen obtained from the water • Excretion – removal of wastes into the water
Porifera • How do they reproduce? • Reproduction can be sexually or asexually. • Adults produce gemmules which can withstand harsh conditions and grow into an adult sponge • Reproduce asexually by regeneration – tear of a piece of sponge and a complete new sponge will appear.
Porifera • How important are sponges to the environment? • Many sponges are large and have irregular shapes and provide habitats • Commensalism and partnerships • EX: bacteria provide food and oxygen to the sponge while the sponge provides protected area.
Porifera • Types of Sponges • Calcareous sponges • Found in shallow waters around the world • Spikes made of calcium carbonate (lime)
Porifera • Types of Sponges • Glass sponges • Skeleton consists of crystalline silicon dioxide • Generally found in deep, tropical waters
Porifera • Types of Sponges • Demospongiae (Bath sponges) • Skeleton is elastic (spongin) fibers • Found in the Caribbean Encrusting Sponge
Phylum Ctenophora Comb Jelly
Ctenophora • Ctenophores (Greek for “comb-bearers”) have eight “comb rows” of fused cilia arranged along the sides of the animal (red rows) • The cilia beat and propel the animal through the water
Ctenophora • Ctenophora are commonly known as comb jellies and are voracious predators • 50 species • Most species are planktonic carnivores and transparent which feed on zooplankton • Light-scattering cilia and bioluminescence • Lack stinging cells but capture prey by sticky cells called colloblasts • Favorite food of sea turtles
Ctenophora • Reproduction • Most are hermaphroditic • Release egg and sperm in water, where sperm must find the egg to fertilize it • Fertilized eggs develop through larval stage that hatches into an adult; no medusa stage Sea gooseberry
Phylum Cnidarians Hydras, jellyfishes, sea anemones and corals
Cnidarians • What is a cnidarian (ny-DAYR-ee-n)? • 10,000 species • Soft-bodied, carnivorous animals • Stinging tentacles arranged in circles around their mouths • Simplest animals to have radial symmetry and specialized tissues.
Cnidarians • Specialized cells of cnidarians • Cnidocytes – stinging cells that are located along their tentacles • Nematocyst – poison-filled, stinging structure that contains a tightly coiled dart.
Cnidarians • Form and Function in Cnidarians • Simple organisms and only a few cells thick • Responses to the environment are carried out by specialized cells and tissues. • Life cycle that includes two different-looking stages: • Polyp stage • Medusa stage
Cnidarians • Polyp stage • Cylindrical body with armlike tentacles. • Mouth points upward • Polyps are usually sessile
Cnidarians • Medusa Stage • Motile • Bell-shaped body • Mouth on the botton
Cnidarians • How do Cnidarians feed? • After paralyzing its prey, cnidarian pulls the prey through its mouth into its gastrovascularcacity
