Phylum Porifera Sponges Porifera “paw-rif-er-uh” Cnidarians

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 Collar cells or choanocytes (koh-an-uh-sytz) are cells that use flagella to move a steady current of water through the sponge. Water leaves thru the osculum

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 Softer sponges have an internal skeleton made of spongin, a network of flexible protein fibers. These are the sponges used as natural bath sponges.

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. Sponges are hermaphrodites – each adult can act as either the female or the male in reproductin.

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 Lack stinging cells

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

Hydras, jellyfishes, sea anemones and corals 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. In this picture, a sea anemone captures a fish that has brushed the trigger of the nematocyst. When triggered, the filament inside uncoils and shoots a barb into the animal

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 gastrovascular cacity