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Weekly Online LessonOnline Lesson ArchiveGrade Level: 2-6
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Swarming Jellies
Huge
numbers of jellyfish are swarming offshore along the northern Gulf of
Mexico. Scientists worry there may be too many jellyfish, that they will
harm other ocean species along America's coast. Jellyfish don't eat other
fish, but they can eat small fish eggs and the plankton that young fish
feed on.
There's good reason to worry. A North American species of jellyfish was accidentally brought to the Russian Black Sea by a cargo ship. The jellyfish multiplied so fast that they soon wiped out a thriving anchovy fishery there.
That
probably won't happen in the Gulf, which has a lot more open water. Still,
jellyfish are so good at filtering out every living thing in the water
that they are likely to cause trouble for commercial fish harvests in
the future.
In this lesson you will learn about jellyfish, what they look like, where they live, and how they grow.
Those That Sting
Jellies
are members of the phylum Cnidaria, which basically means "those
that sting." You can learn more about Those
That Sting from this web exhibit at the Oregon Coast Aquarium
where jellyfish are now on display. Start by clicking Body by Jell-o to
learn about the body parts of jellyfish: the bell, the oral arms, and
the tentacles. Click on any of these parts to learn more. Where is a jelly's
mouth? How much of adult jellies are water? What's good about being made
of mostly water?
Want to see a picture of live jellyfish? Click the Jelly Cam link to see a photo of the jellyfish tank in Oregon. The animals on display are called Oregon moon jellies. Why do you think they're called that?
Jellyfish,
like frogs and butterflies, go through several different body shapes in
their life cycle. Click A
Jelly's Life to learn about its life cycle. Start by clicking
the picture of Adult
medusas, read about this stage, and then go back and click the
next stage.
Can you remember the life cycle of jellyfish? Try the lifecycle fun game to see if you can get the stages in the correct order. Drag the stages around until you get it right.
National Aquarium in Baltimore
The
lifecycle game you just played was part of the National Aquarium web
site. Here you can learn more about Jellyfish
drifters. When the site opens click Jelly
fun facts for some great jelly trivia. How long have jellies been
on the earth? How big can some jellyfish get? What do dried jellyfish
taste like?
There
are over 200 species of jellyfish we know of. Click Species
to learn about some of them. Which species grows to be the longest? Which
has the most dangerous sting to human?. To learn more about how jellyfish
sting, click A
Sting in Action. How do jellyfish sting? What can a swimmer do
to treat a jellyfish sting? (If you can't remember, click sting
to find out).
If you think you know a lot about jellyfish now, try the Jellies Trivia Game. Enter your name to start, and then click Let's go!
My Life As a Blob
You've
learned a lot about jellyfish and about several jellyfish species. Maybe
now you're ready to see some really cool looking ones. Visit Discovery
Online's My
Life As a Blob, a special web feature about . . . well, you can
figure it out.
You can read if you want, but the best thing about this site is the All Jelly Slide Show. As you look at the pictures, try to find the jellyfish parts. (Remember what they are?) Which jelly is your favorite?
Here's one final link for fun. Watch a jellyfish video by clicking Real Video or Quick Time link. It may take a while to load, and you may need to ask for help if the right viewer isn't installed.
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