Sponges and Cnidarians - North Allegheny

Sponges Chapter 9 Section3 Live all over the world (oceans, freshwater rivers and lakes) Sponges

Invertebrate animals No body symmetry Never have tissues or organs Looks like a hollow bag Large opening at one end and tiny pores covering the surface Spikes support and protect sponges body

Sponge: Body Structure Eats tiny single-celled organisms Collar cells that line central cavity, trap the tiny organisms Jelly-like cells inside sponge

digest, or break down, the food Sponges get oxygen from water Sponge: Obtaining Food and Oxygen Asexually Budding: small new structures grow from the sides on an adult sponge Buds eventually break free and begin new life

Sexually Sponges produce both sperm cells and egg cells (do not have separate sexes) Sperm cells released in water, enter another sponge, fertilize its eggs, larva develops Larva: immature form of an animal that looks very different from the adult Sponges: Reproduction

Cnidarians Chapter 9 Section3 Jellyfish, corals, and sea anemones Invertebrates that have stinging cells to capture food and protect themselves Take food into central body cavity

Cnidarians Two different body plans (vase and bowl) Radial symmetry Central hollow cavity Tentacles containing

stinging cells Cnidarians: Body Structure Vase-shaped body plan is a POLYP Sea anemone

Mouth opens at top Tentacles spread out from around mouth Most are attached to underwater surface Body Structure: Polyp Bowl-shaped

body plan is a MEDUSA Jellyfish Adapted for a swimming life Mouths open downward and tentacles trail down Body Structure:

Medusa Use stinging cells to catch animals they eat (prey) Contains threadlike structure with spines Uses tentacles to pull prey to mouth Takes food into central body cavity

Expels undigested food through mouth Obtaining Food Unlike adult sponges, many cnidarians move to escape danger and to obtain food

Jellyfish? Sea Anemones? Movement Asexual

Reproduction Hydras, corals, and sea anemones Sexual Reproduction Jellyfish Reproduction

Colony a group of many individual animals Stony corals and Portuguese man-ofwar Life in a Colony a coral reef is built by cnidarians

coral reefs are home to more species of fishes and invertebrates than any other environment on Earth Coral polyps produce hard, stony skeletons around their soft bodies Stony Coral Contains

as many as 1,000 individuals that function together as one unit Top: gas filled chamber, allows colony to float Bottom: polyps with different functions drift below Some catch prey and help with digestion and reproduction

Portuguese Man-of-War