The word "jellyfish" is often used to describe animals made of gelatinous materials. Some types of jellyfish sting (called jellyfish) and some don't (called salp). When a huge amount of plants or animals suddenly appears, scientists call it a “bloom.” Jellyfish often bloom, which causes problems for fishing and tourism. A common analogy used to describe the delicate way jellyfish leap through water likens the jelly's movements to "a simple form of jet propulsion." Jellyfish have large appetites, including phytoplankton, copepods (zooplankton), larvae, and sometimes even other jellyfish. When jellyfish move "in bloom", they eat literally everything that is in the water or in their way. A jellyfish has a simple digestive system with only one opening. Fun fact: jellyfish are made up of over 95% water. The expected lifespan of a jellyfish is one year, which typically begins with spring birth and becomes an adult during the summer. By the end of summer, the jellyfish's delicate skin is quite damaged, causing problems that ultimately lead to death. However, scientists have recently discovered an "immortal" species of jellyfish, which returns to the larval state as it ages, causing "immortality." Although it is rare for a jellyfish to breed in captivity, it is not uncommon for jellyfish to breed in the wild. They are typically found in coastal waters of all areas, but especially in warm or tropical waters. They are also found in brackish waters with a salt content of 0.6%. Their biomes are coral reefs, tropical coasts, and freshwater lakes. They are also found in oceans and coastal seas. Jellyfish can withstand temperatures as low as -6 degrees Celsius and up to 31 degrees...... middle of paper ......ielts-simon.com. np, January 10, 2013. Web. January 7, 2014. .Katsuki, Takeo, and Ralph J. Greenspan. "The nervous system of jellyfish." Greenspan Laboratory. Network. January 6, 2014. .Whitaker, David J, Rachael King, and David Knott. "Jellyfish." Marine science. Network. January 7, 2014. Watson, Stephanie. "How jellyfish work." How things work. Network. January 6, 2014. "10 Surprising Facts About Jellyfish." Twisted sieve. June 29, 2009. Web. January 6, 2014. "Medusa". Wikipedia. Network. January 6. 2014. .