Jellyfish, sometimes known as Jellies, are aquatic animals that swim freely with a soft gelatin umbrella-shaped body and sweeping tentacles. The tentacles can be used to capture prey or also for protection by emitting a painful sting. The bell part of the body can vibrate which helps the jellies in movement though they depend on ocean currents to move long distances. Jellyfish are classified under kingdom Animalia, phylum Cnidaria, and subphylum medusozoans. The subphylum is further classified into three groups of jellyfish; Scyphozoa which are true jellyfish, Cubozoa which are box jellyfish, and Staurozoa which are stalked jellyfish. Jellyfish are present on ocean surfaces and the deep sea. True jellyfish can only be found in salty water though there are some species of jellyfish present in fresh water like the Craspedacusta sowerbii species. Jellyfish are not considered true fish as they are invertebrates. As long as they feed, fully grown jellyfish spawn every day. The lifespan of jellies differs with species, and some live for a few hours and some for a few years. The Turritopsis dorhnii species is said to be immortal as it can transform from medusa to polyp stage in some circumstances. Jellyfish are carnivorous and they feed on small fish, other jellyfish, fish eggs, and planktons. Jellyfish are growing in numbers due to overfishing of fish that compete for the same food. The Irukandji jellyfish and other species of box jellyfish are said to be toxic. 20 to 40 people die every year from a jellyfish sting in the Philippines alone. Three species compete for the title of the largest jellyfish: the Lion’s Mane jellyfish (Cyanea Capillata), the Nomura’s jellyfish (Nemopilema Nomura), and the Stygiomedusa gigantea jellyfish.
3. Lion's Mane Jellyfish
The Lion’s Mane jellyfish (Cyanea Capillata) is also known as the hair jelly or the giant jellyfish. This jellyfish can be found in the cold subarctic waters of the Northern Atlantic Ocean, Northern Pacific, and Arctic Oceans. The jellies have very visible sweeping tentacles that may resemble a lion’s mane, and this is what gives them the name Lion’s Mane. These jellyfish have a lifespan of one year and only live in cold water. The jellyfish are of different sizes though the bell can get to a diameter size of around 6 feet 7 inches. The smaller jellies are found in lower altitudes and have a bell with a diameter of around 20 inches. The Lion’s mane jellyfish are commonly found in the Western Scandinavian waters, the North Sea, Irish Sea, and the English Channel. The largest documented Lion’s Mane jellyfish was found in 1870, washed up on Massachusetts Bay shores. The jellyfish can mostly be seen during autumn and late summer when they are grown and have been washed to shore by currents. The different sizes of the jellies also come in different colors and the bigger jellies are crimson to dark purple while the smaller ones are light orange, tan, or at times colorless. The Lion's mane jellies can be found in the open sea, but towards the end of their lifespan, they settle in shallow shielded bays. The body of the Lion’s Mane is scalloped into eight parts/Lappets; each lappet has 70 to 150 tentacles arranged in four rows. The tentacles have stinging cells which are sticky. The bigger jellies may have tentacles that can reach 100 feet long. The longest known specimen had tentacles that were 120 feet long. The jellyfish live near the surface and do not go to depths more than 65 feet.
2. Nomura's Jellyfish
Nomura’s jellyfish (Nemopilema Nomura) is a jellyfish that fall under the scientific order of Rhizostomae and is edible. The Rhizostomae jellyfish do not have tentacles but have eight oral arms at the edges of the bell, unlike other jellyfish which have four arms. Nomura’s jellyfish are of the same size as the Lion’s Mane jellyfish. The diameter of a fully grown Nomura’s jellyfish is slightly bigger than the height of an average man. The jellyfish are named in honor of Mr. Kan’ichi Nomura who in December 1921 sent a full specimen of the jellyfish to Professor Kishinouye for studies. Nomura’s jellyfish can grow to be a diameter of 6.6 feet and weigh up to 440 pounds. The jellyfish live in the waters between Japan and China, mostly in the East China Sea and the Yellow Sea. Nomura’s jellyfish mostly feed on zooplankton in their early stages and later prey on fish as they grow in size. The jellyfish is preyed on by humans, tuna, swordfish, sunfish, and leatherback turtles. As from the beginning of the 20th century, the jellyfish have grown in numbers. In Japan, the jellyfish are used in making a vanilla and jellyfish ice cream. Nomura’s jellyfish can also be dried, salted, and eaten as a delicacy. Jellyfish are mostly eaten in Japan, Korea, and Southeast Asia. The collagen of the Nomura’s jellyfish has been used in studies for the treatment of joint diseases.
1. Stygiomedusa Gigantea
The Stygiomedusa gigantea species of jellyfish can be found in the deep sea. The jellyfish are also named Diplulmaris gigantea, Stygiomedusa fabulosa, or Stygiomedusa stauchi. This species is scientifically grouped in the order Semaeostomeae, Ulmaridae Family. This jellyfish species is hardly seen, they have only been seen 115 times in the past 110 years. The species is believed to be present all over the world. The jellyfish is one of the largest invertebrates, however, little is known of about its behavior and ecology. It lives in depths of up to 7,000 feet below the ocean surface. The jellyfish have an umbrella-shaped bell that can measure up to 3 feet in diameter and four arms that resemble paddles which can grow to 32 feet long. The jellyfish do not have tentacles, and they use their arms to capture prey. The Stygiomedusa gigantean species have been seen and filmed off the United States Pacific Coast by scientists and off the Gulf of Mexico and Japan’s coast by remotely operated underwater vehicles.