This article will examine jellyfish commonly known as jellyfish. The jellyfish comes from the phyla Cnidaria. Jellyfish date back over 500 million years and can be found in different ocean environments. And there are also a few varieties that live in fresh water. Despite its name, the jellyfish is not even a fish because it has no vertebrae. Jellyfish are divided into four classes: scyphomedusae (“true” jellyfish), stauromedusae (stem jellyfish), cubomedusae (box jellyfish), and hydrozoa. The body of the jellyfish can take a variety of shapes, from the more familiar bell or umbrella shape, or it can be flat and disc-like, depending on the species. This article will focus on scyphomedusae or “true jellyfish”. We will examine the similar cycle, the habitat, the resources it requires and ethical issues regarding the animal. Let's first look at the mating and life cycle of the jellyfish. There are distinct sexes, male and female, which are not easily distinguished by a sigh. Their reproductive organs are found in the lining of the stomach. Breeding begins when the male releases sperm through his mouth into the surrounding water. These sperm swim to the female where they enter her central oral cavity to reach the eggs. Once fertilized, the zygotes emerge on the mouth arms to develop for a period of time, becoming larvae that settle on the ocean floor and attach to the surface. The resulting polyp begins to bud asexually, releasing free-swimming jellyfish which then develop into adults. Adult jellyfish measure between twelve millimeters and more than two meters in diameter. The largest is Cyanea arctica which can have tenticles over 40 meters long. The lifespan of jellyfish generally varies by a few hours...... middle of paper ......art. A small business in Israel thinks it can help. Through research, they discovered that jellyfish were made of a material capable of "absorbing a large volume of liquids and retaining them without disintegrating or dissolving." They want to apply this research to the production of diapers, paper towels and even tampons. Environmental groups are even urging people to start considering jellyfish as a viable food source. In conclusion, we examined the history, habitat, life cycle, and ethical issues of jellyfish. And although jellyfish have been around for centuries, now more than ever. their presence is noticed. Despite its simple anatomy and short lifespan, the jellyfish has begun to invade waters around the world. It is no longer a small threat that can bite casual swimmers, but an ever-increasing threat to the marine ecosystem..