Cnidaria Flashcards
What was the first group of animals to exist on the ocean floor?
Sponges
What group of animals evolved after the sponges?
cnidarians
How do tentacles give a cnidarian an advantage?
Reach out and jab prey
What two digestive system structures appeared first in the cnidarians?
Mouth and stomach
What allows cnidarians to be able to bend in different directions?
With two set of muscles
How do nerve cells work with muscle cells to give the cnidaria movement?
Electoral impulse trigger other muscles to contract
Why does the video claim that cnidarians were the first active predators on Earth?
They were the first to have venom and be living
How fast are nematocysts deployed?
Like a rifle bullet
What characteristics of nematocysts make them effective for hunting and defense?
Has toxins
How do anemones fight for space on a rock?
Displaying their tentacles with each of their own sack to strike enemy ( weapon sacks )
What do coral polyps eat?
Plankton
What do we call a community of coral polyps?
Coral reefs
What special defensive ability does the anemone called Stomphia have?
Frees itself from rock and moves away, it can swim
Name one group of cnidarians that dominates the upper and possibly the lower regions of the ocean
water column?
jellyfish
How long can a Praya’s body extend, making it the world’s longest predator?
Tentacles become thin strands and body extends
