Joined in 2023 
82 
63 About this deal
When Bruce Robison was just starting out in marine biology, the study of deep-sea life usually involved dragging a net behind a ship. This method was efficient but selective, he recalls. Trawl samples gave scientists a skewed picture of what populates the oceanic water column: large numbers of fishes, crustaceans, and squids–the hard-bodied animals the nets could actually snare–plus “a handful of goo” that was tossed overboard. We’ve been doing this for 15 years now, and yet we still see new stuff almost every dive,” says MBARI scientist Bruce Robison. “And that’s just in Monterey Bay. Our knowledge about the deep sea is still so poor that even after all these years of diving in this one spot, we still see new things all the time.” The jellyfish itself provides a tasty meal for other ocean creatures, particularly sea turtles, who like to guzzle them up regularly. In some cultures around the world, people eat jellyfish, too. In China, they are considered a delicacy, and are also used in Chinese medicine.
Through genetic analysis, biologists are slowly gaining a better understanding of how and when the jellies evolved. Needless to say, fossils of jellies are few and far between. The evidence now suggests that jellies are an ancient life-form, hundreds of millions of years old, and probably predate most of the more familiar, complex animals. But many questions remain. For example, the comb jellies are typically classified into two types, those with tentacles and those without. Which type is older? Did the tentacleless kind appear first and the tentacled kind evolve later? Or did tentacles come first and then, in some comb jellies, disappear over time? Only further study and exploration will tell. What marine researchers know for certain is that the jellies they’ve discovered so far represent only a small fraction of what’s out there. Unlike a lot of other animals, jellyfish don’t have a brain. They also do not have blood or a heart. Their nervous system which is known as a nerve net is very simple and allows them to smell, detect light, and respond to other stimuli. Jellyfish have been around for millions of years, even before dinosaurs lived on the Earth. Pulsing along on our ocean currents, these jelly-like creatures can be found in waters both cold and warm, deep and shallow and along coastlines, too. Some jellyfish are clear, but others are vibrant colours of pink, yellow, blue and purple. They can be bioluminescent, too, which means they produce their own light! These are busy times for jelly discoverers. The use of submersible vehicles has enabled scientists to explore the world of jellies in depth; new creatures are constantly appearing. In February 2004, Raskoff and Matsumoto announced the discovery of yet another deep-sea jelly, Stellamedusa ventana,a tentacleless organism they’ve affectionately named “Bumpy” for the many warty lumps on its softball-size body. And much like jellies, many scientists have even incorporated bioluminescence into their own work lives, often unaware of its original origin. Photoproteins, first isolated from jellyfish several decades ago, are now an integral part of laboratory biology and help researchers do things like mark and identify crucial gene sequences in medical studies.
Fun Facts about the Jellyfish!
All 200 species of jellyfish exhibit radial symmetry. This means that they have a distinct top and bottom, but do not have a left or right side as all of their appendages radiate outwards from a central point, rather like the spokes of a bicycle wheel. A Mediterranean jellyfish. Jellyfish Reproduction The jellyfish’s mouth is found in the centre of its body. From this small opening it both eats and discards waste. And it serves another purpose, too – by squirting a jet of water from its mouth, the jellyfish can propel forward! Cool, eh? Bioluminescence is light produced by a chemical process within a living organism. The glow occurs when a substance called luciferin reacts with oxygen. This releases energy, and light is emitted. An enzyme called luciferase facilitates the reaction. Sometimes luciferin and luciferase are bound together with oxygen into a single molecule, or photoprotein. When an ion such as calcium is present, an ensuing reaction emits light. To glow on a regular basis, an organism must continually bring fresh luciferin into its system. Some acquire it through their diet; others produce their own.
Humans can also be stung by jellyfish which can result in mild symptoms such as pain and blistering, to more serious symptoms including whole-body illness. In some cases, stings can even be life-threatening. Bioluminescence The light is produced by a chemical reaction between a chemical substance called luciferin and oxygen from the environment. This reaction releases energy and as a result, light is emitted. An enzyme called luciferase helps this reaction occur. For an animal to emit light regularly they must continually bring new luciferin into their system. Some animals acquire it through their diet while others can produce their own.
MOST POPULAR
Submersible vehicles also offer a unique window on jelly behavior and ecology. “One of the advantages of working on jellies is that they’re blind and deaf,” Robison says. “They don't seem to mind at all when we fly up to them and zoom in with our lights and cameras. We can make good observations of the interactions of jellies with one another, their prey, and their predators, without disturbing them.” And the jellies themselves, being transparent, offer an additional window onto their lives. “Who eats whom that’s easy to see with a transparent animal,” Robison says. “You don’t have to cut them open to find out what was for lunch.” Jellies were always relegated to an interesting but fringe category of strange, snotty animals in the water,” says Kevin Raskoff, a jelly scientist at the Monterey Bay Aquarium Research Institute. “But once we saw how prevalent they are and the diverse habitats they’re found in, it caused us to rethink their role in ecosystems as a whole.” Many marine biologists suspect that much of the missing carbon has been in front of their noses the whole time in the transparent, gelatinous bodies of jellies. “Jellies are major players in the ocean’s carbon biomass,” Robison says. “They may be an overlooked part of the equation.” Jellyfish are so cool they have even traveled into space! In 1991, some moon jellyfish were sent into outer space on board the Space Shuttle Columbia. This mission was a study conducted by scientists to understand how microgravity affected them.
Great Deal 
New Comment