allikkeni thirukulam
The zebrafish (Danio rerio) is a tropical freshwater
fish belonging to the minnow family (Cyprinidae) of the order
Cypriniformes. Native to the Himalayan
region, it is a popular aquarium fish, frequently sold under the trade name
zebra danio. The zebrafish is also an important vertebrate model organism in
scientific research. It is particularly notable for its regenerative abilities,
and has been modified by researchers to produce several transgenic strains.
Researchers are
keen to understand why apple-shaped people, who carry a lot of weight around
the stomach, are more susceptible to diabetes and heart disease than their
pear-shaped counterparts, who have bigger hips and thighs. An important clue
has come from a study of zebrafish, reported in Proceedings of the National
Academy of Sciences, showing that a gene called Plexin-D1 plays a key role in
controlling where fat is stored and the shaping of fat cells. Earlier human
studies comparing the DNA of people with different body shapes had suggested
that Plexin-D1 might be involved but had provided little information about the
mechanism.
There is another
popular fish ‘Oscar’ nothing to do with Academy awards though ! - Astronotus ocellatus is a species of fish from the
cichlid family known under a variety of common names including oscar, tiger
oscar, velvet cichlid, or marble cichlid. From its native South America, the species was introduced to
other areas, including China, Australia, and the United States. It is
considered a popular aquarium fish in the U.S.
I have posted many a
times on Rajnikant starrer, Shankar directed blockbuster‘Enthiran’- Dr Vaseegaran, a scientist working on
alternative intelligence developing a
humanoid robot which gets rejected by sinister designs. There have been
‘robot fish’ that are charming pets and a couple of years ago, Massachusetts
Institute of Technology (MIT) unveiled a robot fish that it claims can change
direction almost as fast as the real thing. The fish – or “autonomous soft
robot” as it’s described by MIT – could perform escape manoeuvres through rapid
convulsions of its body, powered by carbon dioxide released from a canister in
its abdomen. “The fish was designed to explore performance capabilities, not
long-term operation,” said Marchese in MIT’s announcement of the research. There was another robot fish designed by
Koreans that cleans clothes. It was a
new concept for washing machines - using robot fish. Each fish uses a built in
camera to identify dirt particles, and then swims over to suck them up.
Now
comes the news of ‘Ultra-realistic Robotic Predator’ scaring fish. New York
University engineers have developed a
robotic predator so realistic that it causes fear among real fish. The study
has significant implications for scientific research involving animals. The predator at hand is a red tiger oscar
fish. It might seem small, but not in the eyes of a zebrafish. The latter is
often used in behavioural studies thanks to its versatility. However, there are
a number of issues with using live animals to conduct research, mainly their
unpredictable nature. That’s one of the reasons Maurizio Porfiri, an NYU
professor of mechanical and aerospace engineering, creates bio-inspired robots.
He says
there are a number of advantages to using robots in animal behavior studies,
including consistency and repeatability (the researchers are able to control
their robotic predator as opposed to relying on a live one). Porfiri and his team divided an experimental
tank into three compartments; one was empty, the second contained live zebra fish
and the final one featured three different experimental stimuli. The zebra fish
exposed to real oscar fish and those that spent time with the robotic models
exhibited similar behavior. In fact, the fish tended to avoid the robot more
than the real oscar fish.
“Avoidance
isn’t the only way we can tell a zebrafish is scared,” Porfiri told NYU. “When
these fish are afraid, they also swim differently, and we were surprised to
find that the robotic fish could produce an even stronger fear-related response
than the actual live predator.” In
contrast, the zebrafish exhibited little fear towards animated images of the
predator. “The oscar fish is a known zebrafish predator, but it’s not the most
threatening one out there,” said Porfiri. “We chose a predator that could be
relied upon to scare the zebrafish, but not to the point of complete avoidance
that would mask what we were trying to uncover.”
The study proved to
the team that it’s possible to induce fear in an animal using a robot. Their
findings will be released in the June issue of the Zebrafish journal. Source : http://engineering.nyu.edu/
With regards – S. Sampathkumar
22nd May 2015.
