1 Phylum Porifera The Sponges 2 3 I) Sponges A)Phylum Porifera 1) Means pore-bearing B)Simplest multicellular animals C)No true organs or tissues D)All are sessile 1)Live attached to the marine floor E)Asymmetrical F)Similar to first multicellular organisms G)Some 5000 species, 790 Genera H)First appeared some Million Years Ago 4 5 II) Morphology A)Epidermis: made-up of pinacocytes B)Porocytes: pores where water enters sponge larger, internal feeding chamber C)Osculum: large opening at the top of the sponge 6 II) Morphology D)Choanocytes: collar cells; has a flagellum that creates currents and a thin collar that traps food particles 7 II) Morphology E)Spicules 1) Siliceous or calcereous sponge supporting structures 8 II) Morphology F)Amebocytes: wandering cells that secrete spicules, transport and store food, and transform themselves to help the sponge repair damaged tissue 9 II) Morphology G)Spongin: protein substance that forms a tough, elastic skeleton in sponges 10 11 III) Feeding Mechanisms A)Suspension Feeding: animals that eat food particles suspended in water B)Filter Feeding: sponges actively eat food 1) Different than deposit feeding, which eat food that settles on the ocean floor 12 IV) Reproduction A)Asexual: branch or bud breaks off & grow into a sponge identical to the parent; gemmules B)Sexual: many sponges are hermaphrodites 1)Produce both egg and sperm C)Broadcast spawning: release of sperm into the water 1) Eggs fertilized internally inside sponge 13 IV) Reproduction D)Sexual: many sponges are hermaphrodites 1)Eggs fertilized internally by sperm 2)Release of planktonic larva 3)Settlement & metamorphosis a)Drastic change from larva to adult 4)Adult 14 15 Example Sponges Yellow Encrusting Sponge Tennis Ball Sponge Chimney Sponge Brittle Star Sponge 16 Example Sponges Orange Finger SpongeHeart Sponge Yellow Boring SpongeOrange Ball Sponge 17