Huge Jellyfish
A number of species of jellyfish, among the 200 species, grow to be big. A jellyfish called Nomura is the largest in the world and can weigh up to 200 kgs. They can be bigger than the divers who go down to photograph them but the very size can amaze you. Being carnivores that feed on plankton and other bigger organisms, these huge jellyfish use the toxins in their tentacles to immobilize the prey. Once the prey is paralyzed, it will be sucked towards its mouth. The nutrients from the prey are then sucked into its radial and ring canals. They don't have a complex digestive or respiratory system.
Huge jellyfish lack a brain but they do have sensory organs through which they can detect a prey even when there is disturbance caused due to odor, waves and light. Though considered harmless to humans, they can be a pain to the fishing industry as they reduce the fish population, destroy nets, etc. They also degrade the freshness of the fish because of the poison and toxin it releases.
Giant jellyfish are now moving to parts of the oceans where they didn't live in before because of over fishing and other human activity. The huge jellyfish have caused a lot of trouble in the coast of Japan since 2005. Overfishing leads to the growth of more and more jellyfish. This is because as the population of fish decreases, jellyfish are eaten less and hence their number grows. When the fish population is high, they feed on zoo plankton which will limit the food available for the jellyfish.
They are used in making culinary delicacies and if this catches on, their number could be controlled, which could be a relief for the fishing industry. They are beautiful and are fun to look at and are great material for a documentary. But getting up close to them could be scary and exciting at the same time. Uncontrolled growth in their number could result in damaging the delicate balance that exists in the oceans and the rest of the world. Their number needs to be controlled and it is not an easy job with the humans interfering with nature everywhere.
Learn more about Jellyfish, different Jellyfish Species, general Jellyfish Information, Jellyfish Pets and Jellyfish Safety
Written by Nathan Dickerson and Sudarsana Sinha.