Stories tagged jellyfish
Non-robotic jellyfish: Engineering researchers at Virginia Tech are building robots that mimic the efficient way jellyfish get around.Courtesy Andy Field (Field Offie)Researchers at Virginia Tech are working on several versions of robotic jellyfish that someday could be used by the military, or for mapping the ocean floor, or cleaning up oil spills.
Known affectionately as RoboJelly, the silicone blobs range from the size of a baseball to a giant five-foot floating monster. Each mimics the swimming technique used by jellyfish, those huffing and puffing water-bags that populate the world's oceans.
In nature, most jellyfish propel themselves by the seemingly simple expansion and contraction of their umbrella, using it to push water out like a rocket blast that propels it forward. But the fluid dynamics are a little more complicated than than just expelling out a big blast of water and moving the other way. It's more like when your cigar-smoking uncle would blow smoke rings into the air to impress you. Remember that? I do. These are called vortex rings, and it's the efficiency of the hydromedusean's self-created fluid flow that interest the VT researchers.
Students at VT's College of Engineering use thin layers of silicone - the same material used for swimming masks - to construct the robots. Electric batteries in watertight plexiglass boxes are used to power the mechanical blobs. The researchers are also looking into ways of extracting hydrogen from water to power them.
“Nature has done great job in designing propulsion systems but it is slow and tedious process," said Shashank Priya, associate professor at Virginia Tech, and the project's lead researcher. "On the other hand, current status of technology allows us to create high performance systems in a matter of few months.”
The on-going project involves a number of U.S. universities and industries, and will warrant several additional years of research before any prototypes are released for use. Besides possible military application, RoboJelly could be employed for such things as monitoring ocean currents and conditions, cleaning up oil spills, and studying sea-bottom flora and fauna.
Tags : Researchers at the University of Texas at Dallas and Virginia Tech have created an underwater robot that mimics the movement of a jellyfish. RoboJelly, as it has been dubbed, uses the hydrogen and oxygen gases from water as its fuel. So, theoretically, it would never run out of energy!
To make the robot move, the researchers covered a shape memory alloy, or smart metal (an alloy that "remembers" its original, pre-deformed, cold-forged shape), with multi-walled carbon nanotubes coated with a nano-platinum catalyst powder. When a mixture of hydrogen and oxygen contact the platinum, an exothermic reaction results, which causes the smart metal to change its shape. When the "muscles" relax, the alloy returns to its original form. No electricity, no batteries, and the only waste released is more water - super cool!
This research is sponsored by the US Navy in the hopes that it can be used in underwater rescue missions, or for surveillance purposes.
The site Discovery News has photos of some very strange and scary-looking creatures living in the depths of Australia's Great Barrier Reef. Some are new to science while others - like the anglerfish - have been terrorizing my dreams since childhood.
Pelagia noctiluca aka the mauve stingerCourtesy Wikimedia CommonsBillions of stinging jellyfish have wiped out more than 100,000 salmon in Northern Ireland, essentially decimating the region’s only salmon farm.
The attack, which took place north of Belfast just off the coast of the Glens of Antrim, involved an amazing 10 square mile by 35 feet deep swarm (or shoal) of the jellyfish species Pelagia noctiluca.
"It was unprecedented, absolutely amazing," said John Russell, managing director of the Northern Salmon Company, Ltd. "The sea was red with these jellyfish, and there was nothing we could do about it, absolutely nothing."
Workers for the company battled for hours to get through the huge mass of mauve stingers - as they are commonly known - but they were clearly outnumbered. By the time they reached the net pens all the salmon were either dead or dying from the attack. Russell fears that without some sort of government aid the company will be forced to go out of business.
Swarms of mauve stingers are not uncommon. However, they’re mostly known for stinging swimmers in the warmer waters of the Mediterranean. It was rare to see them as far north as Great Britain until recently, presumably due to climate change.
Here's some great video posted on YouTube by NewScientist of a mauve stinger swarm shot near the Balearic Islands in Spain and elsewhere in the Mediterranean.
STORY LINKS
Reuters Science News
UPI Story
Story in Minneapolis Star Tribune
Squish it down, roll it out, and it becomes a worm: Photo NOAA.
When it’s related to jellyfish. In 1851 scientists discovered an odd marine worm called Buddenbrockia. Unlike other worms, it has no internal organs. According to Oxford zoologist Peter Holland, “It has no mouth, no gut, no brain and no nerve cord. It doesn’t have a left or right side or a top or bottom – we can’t even tell which end is the front!”
No one knew where exactly if fit on the evolutionary tree. Until now. Holland studied the creatures DNA and found it is actually a close relative of jellyfish, sea anemones and coral.
Before you shrug your shoulders and say “so what?,” realize that Buddenbrockia is a parasite, and comes from a whole family of parasites. It devastates salmon fisheries, and has been hard to eradicate, since the fish farmers didn’t know what they were up against. Now we do.
Holland also notes that this research was made possible by the Human Genome Project, which decoded all the DNA in the human body. Not that human genes have anything much to do with jellyfish and worms. Rather, the Human Genome Project developed new, powerful ways to quickly study DNA. Those methods are now available to other researchers who could never have developed them on their own. In science, we call this the Trickle Down Effect.
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Jellyfish Video
A small freshwater jellyfish swims around a jar as science museum visitors look on.
I have to admit that at first we thought it was a joke. We heard that a Science Museum volunteer had brought in a "freshwater jellyfish" to the Collector's Corner. We were even momentarily fooled when we looked at the jar full of water because it looked empty. However, as we peered closer we saw three amazing creatures about the size of a quarter bobbing around in a jar of Minnesota lake water.
Science Museum volunteer Will Hirsch and his neighbor Tim McDonough found these unique creatures in Lake Jane near the city of Lake Elmo, MN. What they found was the subject of a question to the Minnesota Department of Natural Resources a couple years ago:
In August 2003 I was fishing on a Minnesota-Ontario border lake and noticed hundreds of round, translucent discs about the size of a quarter rising to the surface. The discs had an irregular bluish central pattern and were soft, flexible, and slimy. What were they?
Jim Collinge
Detroit LakesYou likely were looking at freshwater jellyfish (Craspedacusta sowerbii), says DNR research scientist Gary Montz. These little animals grow attached to under-water surfaces for part of their lives, then form buds that turn into the floating form, called a medusa. Freshwater jellyfish can appear in large numbers in lakes during late summer. Like ocean jellyfish, they capture their food-mainly zooplankton-with stinging -tentacles. Unlike ocean jellyfish, they cannot sting or harm you.
So what Will and Tim had discovered was the medusa form of a Craspedacusta sowerbii. These little creatures have been reported in Minnesota and almost every other state in the continental US. These animals like still waters, so they won't be found in rivers or streams. As they float around they passively feed on even tinier animals that are found in almost all lakes called zooplankton. They are easiest to spot in August and September, so keep an eye out for them next time you go swimming or fishing at your local lake.
How do they reproduce? How did they get here? What kind of water do they live in? Researchers at the Indiana University of Pennsylvania, Japan, and Australia are all studying these strange creatures to come up with answers to these questions.
Have you seen a jellyfish in any of Minnesota's lakes?
