Hello!  I am so bad about posting, you probably barely remember me.  Today I am posting about...if you read the title you should have guessed, but if not, I am posting about jellyfish by request of my very good friend, Rose.  Oh and be sure to check out her blog and read her post about our little adventure. 

Jellyfish are invertebrates which means they have no spine.  Amazingly jellyfish can be found in every ocean in the world.  There are many species of jellyfish.  Some live in the deep ocean, but most live in shallow waters.

A jellyfish has no head, brain, heart, eyes, or ears.  Jellyfish have touch receptors on their tentacles and around their mouths to help capture food. These touch receptors may also detect vibrations in the water caused by the movement of a fish, crab, or other animal swimming by. Jellyfish do not have a nose or tongue. They have special cells that smell and taste.  These cells are scattered all over their bodies. Sea jellies do not have eyes like human eyes, but many have light-sensitive organs around the margins of their bodies.

To capture prey for food, jellyfish have a net of tentacles that contain poisonous, stinging cells. When the tentacles brush against prey , or a person, thousands of tiny stinging cells explode, launching barbed stingers and poison into the victim.  In some species these stings can be quite dangerous, but in most species they are just painful.

Most jellyfish pass through two forms during their life cycle. The first is the polyp stage, when the jellyfish takes the form of either a stalk which catches passing food, or a similar free-floating configuration. The polyp's mouth and tentacles face upwards.  In the mature stage, the jellyfish is known as a medusa. Medusae have a umbrella-shaped body called a bell. The medusa's tentacles hang from the border of the bell.

Jellyfish can be smaller than an inch in diameter, but some may grow to be 7 feet across!!!  Their tentacles have grown in some cases to be 100 feet long.  It is estimated that there are about 2000 different types of jellyfish.  Out of those 2000 only 70 species are really dangerous to humans.

Jellyfish usually drift with the current, but on occasion they swim. Jellyfish swim by rhythmic pulsations of their bellshaped bodyl. The movement is very like an umbrella being open and shut slowly.

Fun Facts...

The name jellyfish is considered by some to be incorrect.  It is actually, because jellyfish are not fish.  So, jellyfish are also called sea jellys, or just jellys.

Most jellyfish don't live more than 6 months.

A group of jellies are often called "smacks".

This jelly appears to be almost a pinkish color!A "smack" of jellyfish.  Don't they look almost pretty?This jelly has long tentacles, and I believe it is a Sea Nettle, which is one of the more dangerous jellys.

This is a flower hat jelly.

Well, I hope you enjoyed that.  I enjoyed learning more about jellyfish also.  If any of you have any requests of marine creatures that you would like me to post about, please leave me a comment and tell me.  I know, I always say this, but I will try to post more often.  Maybe you could leave me comments and remind me to post soon.  Thanks.

Niki