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Ep300: Jellyfish · Kidcast Daily

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  Spin the wheel, Let's take a ride.
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  Sports and science bursting from inside a world of wonder.
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  Open wide. Come.
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  On. Kids, let's amplify kid cats.
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  Daily starts your day. Fun and laughter come your way.
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  Sports and trivia games galore. Welcome to Kick Ass Daily, where
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  we bring news, trivia, fun facts, and more just for curious
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  kids like you. Today we are exploring
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  jellyfish, the ocean animals that can look like floating
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  umbrellas, ribbons, or clear bubbles.
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  You might have seen one in an aquarium, or maybe you have
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  spotted a washed up jellyfish on a beach.
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  Jellyfish can be beautiful to watch, and they're also
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  important parts of ocean food webs.
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  First, what exactly is a jellyfish?
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  A jellyfish is an invertebrate, which means it has no backbone.
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  It is part of a large group of animals called Nydarians.
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  Other Nydarians include sea anemones and corals.
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  Jellyfish have a simple body design, but that does not mean
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  they are simple to survive. They have been living in Earth's
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  oceans for a very long time and they are found from warm
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  tropical waters to cold seas. A jellyfish body has a bell,
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  which is the main rounded part, and many species have tentacles
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  hanging down. Under the bell is an area where
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  the mouth is located. Jellyfish do not have a head
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  like a dog or a fish. They also do not have a brain.
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  Instead, they have a nerve net, which is a spread out system of
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  nerves that helps them sense their surroundings and move.
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  Here is a trivia question to start us off about how much of a
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  typical jellyfish's body is made of water.
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  For many jellyfish species, it is about 95% water.
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  That is one reason jellyfish can look clear and feel slippery.
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  It is also one reason they can be hard to pick up and carry
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  even when they look big. So how do jellyfish move?
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  Many jellyfish swim by pulsing their bell.
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  They tighten the bell and push water backward, and that helps
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  them glide forward. It takes energy to do this, but
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  jellyfish are also carried by currents and waves.
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  That means a jellyfish might not always go exactly where it
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  wants. Some types are stronger swimmers
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  than others. If you have ever tried walking
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  in a swimming pool while the water pushes against you, you
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  already know what it feels like to move while water is moving
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  too. Now let's talk about how
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  jellyfish eat. Jellyfish are carnivores,
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  meaning they eat other animals. Many eat tiny drifting animals
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  called plankton. Some eat small fish or fish
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  eggs. Their tentacles have special
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  stinging cells called nitrocytes.
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  Inside those cells are tiny structures that can fire very
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  quickly when touched. The sting helps the jellyfish
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  catch food. People sometimes ask if a
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  jellyfish sting is always dangerous.
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  Most jellyfish stings are not life threatening, but they can
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  hurt and it is best not to touch jellyfish in the water or on the
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  sand. Even a jellyfish that is no
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  longer alive can sometimes still sting.
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  Do all jellyfish have long trailing tentacles?
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  No. Some jellyfish have short
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  tentacles, some have thick frilly arms, and some have very
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  small tentacles that are hard to notice.
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  The shape depends on the species and what it eats.
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  Jellyfish do not chew food with teeth.
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  After prey is caught, it is moved to the mouth.
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  Many jellyfish have a gastrovascular cavity, which is
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  a space inside the body where food is digested.
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  Nutrients then spread through the body.
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  Jellyfish do not have lungs. They absorb oxygen directly
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  through their thin tissues from the surrounding water.
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  Now for an important part of the jellyfish story, the jellyfish
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  life cycle. Many species have two main
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  stages. One stage is the Medusa, which
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  is the swimming jellyfish shape most people picture.
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  Another stage is the polyp, which usually attaches to a
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  surface like a rock, a dock, or the sea floor.
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  The polyp can be small and easy to miss in many species.
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  Polyps can make new jellyfish by forming tiny stacks that break
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  apart into young jellyfish. This life cycle helps jellyfish
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  populations grow when conditions are right, such as when there is
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  plenty of food and the water temperature is suitable.
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  Here is another trivia question. What is a large group of
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  jellyfish moving or drifting together often called?
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  It is often called a bloom. People also use other words, but
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  bloom is common in science and news reports.
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  Blooms can happen when jellyfish grow quickly in number.
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  They can be noticed by swimmers, fishers, and scientists.
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  Where do jellyfish live? Jellyfish live in every ocean.
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  Some live close to the surface, where sunlight helps grow
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  plankton, and some live much deeper, where it is dark.
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  Some jellyfish even migrate up and down in the water each day,
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  moving to different depths depending on the time.
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  That can help them find food and avoid predators.
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  Can jellyfish live in freshwater, like a lake or a
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  pond? Yes, a few kinds can.
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  One example is the freshwater jellyfish cross, but Acustis our
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  by which has been found in lakes and reservoirs in many parts of
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  the world. It is usually small, and people
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  often only notice it when conditions cause many to appear
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  at once. Jellyfish have predators, too.
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  Sea turtles eat certain kinds of jellyfish.
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  Some fish and seabirds also eat them.
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  Even other jellyfish can eat jellyfish at the same time.
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  Jellyfish can help other animals.
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  Small fish sometimes hide among jellyfish tentacles for
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  protection from predators, although they have to avoid
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  being stung. Let's add a did you know moment
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  about jellyfish bodies. Did you know jellyfish do not
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  have bones and they also do not have a heart?
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  They move nutrients through their body without a pumping
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  organ the way humans do. Their simple body plan works
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  well in water, especially because water supports their
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  shape. Here is a yes or no question
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  that teaches a new detail. Do some jellyfish have eyes?
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  Yes, some jellyfish, including box jellyfish, have groups of
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  eyes. These eyes can sense light and
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  help the jellyfish notice shapes around it.
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  Jellyfish eyes are not like human eyes, and different
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  species have different levels of vision, but it is still
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  impressive for an animal without a brain.
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  People interact with jellyfish in many ways.
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  Aquariums often display jellyfish in special round tanks
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  that keep water moving because jellyfish can be delicate.
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  Scientists study jellyfish to learn about ocean ecosystems
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  because jellyfish numbers can change when water temperatures,
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  currents and food supplies change.
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  In some places, jellyfish are also eaten as food after careful
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  preparation, but that depends on the species and local
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  traditions. If you are at the beach, the
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  safest rule is simple look but do not touch.
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  If you see jellyfish in the water, you can calmly move away.
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  If you see one on the sand, remember that waves may have
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  brought it in recently, and stinging cells can still work.
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  Beaches sometimes post signs when jellyfish are common, and
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  lifeguards can give advice about local conditions.
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  Now let's do one more trivia question.
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  What is the name of the stinging cells that jellyfish use to
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  capture food? They're called nitacites.
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  Inside them are tiny structures that can fire when triggered.
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  This is one of the key features that connects jellyfish with
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  corals and CNMS. Before we finish, let's quickly
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  recap what you learned today. Jellyfish are invertebrates in
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  the Nyderian group, and many are made of about 95% water.
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  They move by pulsing their bell and by drifting with currents.
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  They catch food using tentacles and stinging cells called
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  nitrocytes, and they digest food inside a body cavity.
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  Many jellyfish have a life cycle with a swimming Medusa stage and
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  a bottom attached polyp stage. A large group can be called a
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  bloom. Jellyfish live in oceans all
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  over the world and a few can even live in freshwater.
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  Some jellyfish have eyes that sense light and shapes.
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  And most importantly for beach days, it is best to observe
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  jellyfish without touching them. Thanks for listening to Kid Cast
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  Daily. Come back soon for more news,
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  trivia, fun facts, and more just for curious kids like you.
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