Interesting Cnidarians

Hydras- a Hydrozoan

Freshwater hydrozoan Spend most of life as

polyp Can move with a

somersaulting movement

Portuguese Man-Of-War

A type of hydrozoan that grows in a colony

One of the polyps (pneumatophore) becomes a float to keep the colony on the surface

also known as bluebottles for the purple-blue color of their pneumatophores

They may produce very long tentacles(up to 50m)

the poison in the nematocysts is very strong and causes humans great pain (but rarely deadly)

JellyfishMost of life is as a medusa

The sting of most jelly fish are harmless to humans, but the tiny, Australian jellyfish can kill you in 3-20 minutes.

Box jelly

Sea Anemones & Corals

Only have the polyp stage

Most ecologically important invertebrates

Sea anemones are solitary polyps

Sea anemones

Clownfish and Sea Anemone –

Symbiotic relationship • sea anemone receives protection from polyp-eating

predators, like Butterfly Fish, which the clown fish chases away.

• the anemone also gets fertilizer from the feces of the Clown Fish

• tentacles protect clown fish from its predators

Corals

Grow in shallow, tropical water

Produce skeletons of CaCO3

Most are colonial, creating coral reefs

Entire ecosystems revolve around coral reefs

Coral reefs also protect the land from the ocean swells and waves

Corals produce chemicals to prevent being overgrown by other organisms. Some of these chemicals have been used as anti-cancer medications