No brain. No bones. Still deadly: Meet the 120-foot-long jellyfish in the world

Do you know! The world’s longest jellyfish has neither a brain nor bones. Yes, this is true, according to a recent publication in the scientific journal Frontiers in Marine Science, the Lion's Mane jellyfish, scientific name Cyanea capillata, is one of the most structurally complex ‘brainless’ predatory species in the entire ocean. Operating without a centralised nervous system or bones, the Lion's mane uses a decentralised nerve net as its primary means of coordinating its giant gelatinous body; the bell diameter of the Lion's mane has been recorded at greater than 2 meters.Despite lacking traditional organs, this creature demonstrates how evolution can produce highly efficient survival systems, proving that intelligence and coordination in nature do not always depend on a centralised brain or rigid body structures.Research published in the scientific journal PLOS One confirms the extraordinary and unique structure of the predator Jellyfish; it consists of a very large number of stinging tentacles that make up its ‘mane.’ The Lion's mane has approximately 1,200 stinging tentacles, separated into 8 clusters, on its mane, and can have tentacles with a total length of up to 36.6 meters (120 foot); the Lion's mane can use those long stinging tentacles to create a giant, venomous net for capturing prey.One of the most recognisable features of this jellyfish is the ‘mane,’ which is why it's commonly referred to as the ‘King Mane’. A research article in PLOS One states that the ‘mane’ portion is not actually made of hair, but contains around 1,200 strands of highly elastic tentacles that are about 0.5 millimetres thick and are grouped into eight separate clusters. When extended, these tentacles can be up to 36.6 meters (120 foot) long and give the jellyfish a shaggy appearance similar to a lion's mane in colour and texture. Cyanea capillata (Lion’s mane jellyfish) is not only the largest Jellyfish in the world, but also one of the longest animals on Earth. Not only does the bell of this Jellyfish reach a diameter greater than 2 meters, but it also has absolutely incredible tentacles! According to a research article published in PLOS One, one tentacle of the Lion’s Mane Jellyfish was measured at an incredible 36.6 metres. The tentacles of this Jellyfish alone are longer than the average Blue Whale, which typically can grow to 30 metres long.How can such a large creature survive without bones or a brain? According to another research study published in Frontiers in Marine Science, the Lion’s mane jellyfish accomplishes this by using a decentralised nerve net instead of having one central nervous system. Rather than having one area that functions as the brain’s command centre, the Lion’s mane jellyfish has sensory neurons spread out over its entire gelatinous body. This enables it to sense light, chemicals, and vibrations all over its extreme length (120 feet) and provides the means of coordinating all its movements using a hydrostatic skeleton - supported completely by pressure from within its body.The ‘mane’ of a jellyfish provides a means for the prey (fish and smaller jellyfish) to come into contact with the jellyfish's nematocysts (stinging cells) and for the jellyfish, as a predator, to bring its prey to its mouth. As observed, the king mane jellyfish has about 1200 venomous filaments on the surface of its mane, which serve as a form of a large, floating, venomous net to capture fish and smaller jellyfish. Since jellyfish are not able to hunt for food actively (having no brain), they will rely on the large surface area of the filaments to capture their prey. When an animal makes contact with the filaments, multiple stinging cells of the jellyfish will fire and paralyse their prey before drawing them toward their mouth at the bottom of the bell shape of the jellyfish.