Today… Bellringer: Are animals autotrophs or heterotrophs? Explain your answer. Review Section 1 – What is an animal? Notes on Sponges and Cnidarians

Sponges -and- Cnidarians Science 6

Today’s Goal… I can describe the characteristics of sponges and cnidarians.

Sponges Plant or animal? Adult sponges are sessile – remain attached to one place Sponges can’t make their own food About 15,000 species of sponges identified

Sponges Most live in oceans, some in freshwater Bodies made up of two layers of cells Filter feeders Filter food out of the water that flows through their body

Sponges Not many animals eat sponges Their soft bodies are supported by sharp, glass-like structures called spicules Other sponges have a material called spongin which is similar to foam rubber and makes them soft and flexible Some have both

Sponges Reproduction Asexually and sexually Asexual through budding A bud on the side of a parent sponge develops into a small sponge or a new sponge grows from pieces of a broken sponge One sponge can produce both egg and sperm for sexual reproduction Figure 5 on page 502

Sponges Let’s see more about sponges!

Cnidarians Jellyfish, sea anemones, hydra, and corals Have tentacles surrounding their mouth Tentacles shoot out stinging cells called nematocysts to capture prey Radial symmetry allows them to locate food in any direction

Cnidarians Hollow bodied animals with cells that are organized into tissues Two different body forms Polyp – vase shaped body (sea anemone and hydra) Medusa – free-swimming, bell-shaped body (jellyfish) Some have both these forms Page 503

Cnidarians Produce sexually and asexually Figure 6 Polyps reproduce asexually by budding Some polyps reproduce sexually by releasing egg or sperm into water Medusa reproduce sexually to produce polyps, then polyps reproduce asexually to form medusa Figure 6

Cnidarians Learn more about Cnidarians!

Real Pics Sponges

Real Pics Cnidarians