For how many jellyfish there are in every ocean on the planet, there is surprisingly very little known about the species overall. Jellyfish come in many different shapes and sizes, and their biological genetics are leading the way for scientific breakthroughs in medicine and health-related programs every year. They are one of the very few oceanic organisms that have changed very little, if not at all, over the millions of years they have been around for. This article will be more on terms of research and facts, rather than their origin, though.
So jellyfish are referred to as Medusa’s in their order of Cnidaria. This means that unlike their relatives of coral, anemones and hydroids, they are a free floating organism with the ability to move on their own. With calm waters, they are able to swim 2 to 3 miles per hour, but usually rely on currents for travel to reduce their swimming efforts. If high tides come in, then they will not be able to swim against it, causing many to wash up on shore like you may see at the beach. Jellyfish also do not rely as heavily on the zooxanthellae (a type of algae or protist) living inside of them in comparison to the rest of their family. Their bodies consist of 96% water, which is higher than most, if not all, species on the planet in terms of body-to-water ratio. With this type of body, they are able to regenerate destroyed nematocysts; they will move organic matter from their other tentacles and make themselves symmetrical again.
Despite popular skepticism, jellyfish do possess a high amount of intelligence. They are aware of their surroundings in most circumstances, and can differentiate what is food and what is not. They are also known to create groups, which for jellyfish are known as a bloom. They will all manifest in areas deemed as high traffic zones for shoaling fish, and wait for stragglers to come into contact with their nematocysts (tentacles), which then will envenom and kill them. They will even travel to highly polluted areas and wait to ambush fish hoping to escape the pollution. Talk about a brutal killer…
Jellyfish are known to have a set of 24 eyes, and some species can see in color. They respond to almost all colors, but cannot see white. How the heck were we able to determine this? There was a test done in the Pacific Islands maybe a decade ago where scientists put colored poles down into estuaries where the jellyfish migrated to. Each jellyfish was able to recognize the poll based on color and move away from it. However, when the scientists put down a white pole, some of the jellyfish kept bumping into the pole as if they did not know it was there. So this led to even more questions on how their eyes and net nerves actually work, and why the color white of all colors was not recognized by them. While this test was done on members of the box jellyfish family, it has been debated if other species can actually see all of these colors as well. Some scientists have tested the wavelengths in other species’ eyes, but have had either inconclusive results or has only been theorized that they can only see in black and white. So this topic has been debated in terms of their spectrum of sight, and may never be officially resolved for what colors other jellyfish species can see, if any.
What We Don’t Know
Despite how much research has been done on jellyfish, there is still a lot that we do not know about them. For one, we know that they breed asexually and can split themselves to create another organism. However, we do not know what age they do this at, nor how old a jellyfish is at all based upon observation. Most species in the ocean have characteristics that distinguish how old they are, but this is not the case with jellyfish. The age is also much harder to determine since some species such as the immortal and moon jellyfish are able to regenerate their older cells. This works similar to flipping on and off a light switch. Once a cell in an immortal jellyfish’s body becomes too old, it will flip it and turn the cell new again. There is an entire lab in Japan dedicated on learning the complexity of this, and how we may try to use it in the medical field to renew our own cells. The moon jellyfish works a little bit differently, where whenever they reach their time of death, a new polyp will emerge from their body from their old cells and live again. A better way to think of this is in respect to the mythology of a phoenix; where whenever the phoenix dies it will rise again as a baby from its ashes. There is still a lot to be answered on how this works, or if more jellyfish can also renew their cells.
In Case of Stings…
The common myth about relieving the pain of jellyfish stings is to urinate on the affected area. Do not do this! This has been known to cause infection on top of the sting itself. The true remedy to a jellyfish sting is to soak the inflicted area with vinegar. This will prevent the nematocysts from injecting their toxins into your body and will heal the area in about half an hour. If there is no vinegar available around you, (I mean who really carries a bottle of vinegar to a beach?) then rinse the area in sea water or rubbing alcohol. I cannot guarantee any of this for box jellyfish stings, though. Their sting is lethal and have been known to kill humans in 3 minutes, which is faster than you can get out of the water.