Porifera & CnidariaChapter 35

Kianat Zamir, Molly Bicksler & Rebecca Krick

Songes- PoriferaSponges are classified into the animal phylum

Porifera, meaning, “pore bearer.”

Sponges- SessilesA sponge is a sessile because “sessile”

attach themselves to a surface and stay stuck. This is the type of behavior a sponge practices in it’s environment.

Sponges- VariationsSponges vary in almost every way:Size & shape- 1cm to 2 metersColorCactus & moss like Blob or fungus likeOver 10,000 species

Sponges- Collar Cells & OsculumSponges have 2 cylinders lined with collar

cells that have flagella to help penetrate the sponge with water. This water eaves through the osculum, the opening at the top of the sponge.

Sponges- Collar Cells & Osculum

Sponges: Spongin vs. Spicules Spongin: fibers that give the sponge it’s shape & keep it from collapsing

Spicules:Skeleton made of tiny calcium carbonate or little spikes of silicon dioxide

Sponges – Filter Feeding

Most sponges feed by screening food out of the water that the collar cells pump through their body since they cannot pursue their food.

Nutrients pass from the collar cells to other cells that crawl about within the body wall, bringing nutrients to the rest of the body.

This niche is important in nature because carbon dioxide and other wastes produced by the sponge’s cells diffuse into the water passing through the sponge. Which helps to clean out the water of bacteria and other diseases.

Sponge ReproductionRegeneration : is the ability to

regrow missing parts; its important in sponge reproduction because even a small piece of sponge can regenerate into a complete new sponge.

Mobile Larva: sperm is released into the water from one sponge and enters the pores of another sponge. Collar cells in the second sponge engulf the sperm and transfer them to amebocytes which carry the sperm to an egg. After the egg is fertilized it develops into larva.

Phylum Cnidaria Hydra Jellyfish Coral

Polyp vs. Medusa Polyp – has a vase shaped,

elongated form with a thin body wall, its tentacles pointing up; its specialized for sessile existence.

Medusa –has a bell shaped round form with a thick body wall, with its tentacles dangling; its specialized for swimming

Cnidaria CharacteristicsGastrovascular Cavity – a hollow in the center of the body

which has a single opening, or mouth.

Tentacles –flexible extensions which surround the mouth.

Cnidocytes – specialized cells used for defense and capturing prey. In some cnidarians, the cnidocytes are concentrated in the epidermis, especially on the tentacles.

Cnidaria Characteristics

How do Cnidarians feed?• Vocab you should know:

~ cnidocytes- specialized cells used for defense and capturing prey~ nematocyst- organelle that has a long filament coiled up inside it

They feed by using tentacles to capture small animals with their nematocysts and paralyze them with the poison they inject.

The tentacles then push the prey into the gastro vascular cavity through the mouth.

Enzymes in the gastro vascular cavity break-up the prey and the cells lining the cavity absorb the nutrients.

Undigested food exits through mouth.

Significance of the Portuguese man-of-war

It lives as a colony of medusae (a saucer-shaped or dome-shaped, free-swimming jellyfish or hydra) and polyps.

Gas-filled float measures 30 cm (1 ft.) across, this keeps the colony at the surface of the ocean.

Polyps are used for feeding, digestion, or sexual reproduction. Tentacles are 20 m (65ft) long and dangle from the feeding polyps that

carry large numbers of cnidocytes. Poison in the cnidocytes can be painful and even fatal to humans

How jellyfish, hydra, and coral move

◊ Jellyfish:~ move by using a pulsing motion of the cup

◊ Hydra:~ moves when the base makes bubbles of gas, which cause it to float

upside down on the surface of water. They can also somersault to move.

How jellyfish, hydra, and coral move cont.

• Vocab you should know:~ coral reef- a rock-like formation

◊ Coral- uses regeneration (regrowth) to move

Why coral is important in their ecosystem

Coral provides oxygen for the ocean, like how trees provide oxygen on the earth.

This is what happens when coral dies off, there isn’t enough oxygen for creatures to survive.

This is what a healthy coral looks like.

Symbiotic relationship between sea anemones and clownfish

The sea anemones stingers protect clownfish from their predators. (Like in finding nemo )