Introduction

The Aurelia Aurita, which is better known as a moon jelly, is considered the most common species in the genus Aurelia. It is distinguished from other jellies by its horse-shoe shaped gonads. Jellies are invertebrates. They have no heart, brain, or bones; in fact, they are 95 to 97 percent water! The rest of their body is made up of protein and minerals.
Jellies are important to know about because they are very unique creatures. Their appearance as well as reproductive practices makes them stand out among other sea life. I will also be informing you about where jellies live, what they eat, and how they move.

What Do They Look Like?

The moon jelly is mostly clear with some white in its body. Its color can vary though depending on its diet. If the jelly has eaten mostly crustaceans, it will turn pink or lavender and if it has been feeding on brine shrimp, it will have an orange tint. It has radial symmetry meaning that its body parts are arranged around a central point in a symmetrical way. An adult has a diameter between 20 to 40 centimeters.

Pink/Purple Moon Jelly

Orange Moon Jelly

Where Jellies Live

Jellies are commonly found in the waters off California, Japan, and the East Coast of the United States in the Atlantic Ocean, Arctic Ocean, and Pacific Ocean. They prefer the tropics where the water is between 9 and 19 degrees Celsius, but they can be found as far north as 70 degrees latitude and as far south as 40 degrees. Usually, they are an inshore species meaning that they often dwell in places like estuaries and harbors.

The shaded areas are places where jellies are likely to be found.

Diet

The moon jelly is carnivorous and often feeds on plankton, mollusks, fish eggs, and other small jellies. It stings these animals with specialized stinging cells that have small barbed tentacles that paralyze the prey and bring it to the body for digestion.

Stinging Cells

Movement

Jellies are manly drifters that move with the current. They are capable of limited motion by pulsating their bell. When they do this, they move horizontally allowing them to catch food with their tentacles spread out over the larges area possible. They have sensory organs around the rim of the bell that help the jelly to maintain balance. It stimulates nerve endings that cause the muscles to pulse and turn the jelly right side up.

Reproduction

Jellies are able to reproduce in two different ways: by producing polyps and medusa. A mature polyp reproduces by budding which is asexual. It forms an entire colony of polyps. The medusa then swims off and matures. Then that medusa can reproduce sexually by releasing either egg or sperm into the ocean. When the two meet, a zygote is formed. This develops into larva. When the larva is mature, it leaves the adult medusa, finds a surface to attach to, and develops into a new polyp. (click to view larger image)

References and Credits

References:
Scyphozoans http://scyphozoans.tripod.com/

Jellyfish. http://www.tqnyc.org/NYC074558/Jellyfish%20Life%20Cycle.html

Wikipedia. http://en.wikipedia.org/wiki/Moon_jelly

Rodriguez, R., Animal Diversity Web http://animaldiversity.ummz.umich.edu/site/accounts/information/Aurelia_aurita.html


Credits:
Introduction Post:
http://images.google.com/imgres?imgurl=http://www.pnwscuba.com/critterwatchers/critter%2520of%2520the%2520month/moonjelly.jpg&imgrefurl=http://www.pnwscuba.com/critterwatchers/pnwmarinelife2007.htm&h=297&w=400&sz=32&hl=en&start=3&tbnid=GU5Ke-V0d5nA2M:&tbnh=92&tbnw=124&prev=/images%3Fq%3Dmoonjelly%26gbv%3D2%26hl%3Den
Appearance Post:
Symetry: http://www.livingjelly.com/
Orange jelly: http://www.sfgate.com/cgi-bin/blogs/photoblogfl/detailnc?entry_id=15220
Purple jelly: http://florent.us/reef/pix/thumb/moonjelly1.jpg

Where Jellies Live Post:
Estuary: http://images.google.com/url?q=http://kentsimmons.uwinnipeg.ca/16cm05/1116/16biomes.htm&usg=AFQjCNF8qfZWbZ7PgS1o199Ejs-k52j6wQ

Diet Post:
http://www.mindfully.org/Water/2005/Plankton-Vanishing12jul05.htm
http://www.junglewalk.com/shop/Products/Butter-clam-Tote-Bag-8080.htm
http://www.valdosta.edu/~mtrejo/topic.html
http://www.amonline.net.au/exhibitions/beyond/holoplankton/holoplankton06.htm
http://www.newscientist.com/blog/invention/2006/08/jellyfish-injections.html

Reproduction Post:
http://www.teara.govt.nz/NR/rdonlyres/8ECD9A26-0A51-4971-9B87-9E912B922F86/123485/di5355enz.jpg