JELLYFISH are much smarter than previously thought, new research has revealed.
The new study, published in the journal Current Biology, found that poisonous Caribbean box jellyfish can learn at a far more complex level than ever imagined.
2
2
This is despite only having 1,000 nerve cells and no centralized brain.
The new research changes our fundamental understanding of the animal’s brain, scientists said.
It could even reveal more about our own brains and the process of dementia.
JELLYFISH
Jellyfish have been around for more than 500million years but until now they’ve been thought of as simple creatures with limited learning abilities.
The prevailing scientific opinion is that more advanced nervous systems equate with more advanced learning potential in animals.
Jellyfish and their relatives, collectively known as cnidarians, are considered to be the earliest living animals to develop nervous systems – and to have fairly simple ones with no centralized brain.
Neurobiologist Professor Anders Garm has been researching box jellyfish, a group commonly known for being among the world’s most poisonous creatures, for more than a decade.
The fingernail-sized species live in Caribbean mangrove swamps where they use their impressive visual system, including 24 eyes, to hunt for tiny copepods among the roots.
Most read in News Tech
Prof Garm, of the University of Copenhagen in Denmark, said: “It was once presumed that jellyfish can only manage the simplest forms of learning, including habituation – the ability to get used to a certain stimulation, such as a constant sound or constant touch.
“Now, we see that jellyfish have a much more refined ability to learn, and that they can actually learn from their mistakes. And in doing so, modify their behavior.”
He said one of the most advanced attributes of a nervous system is the ability to change behavior as a result of experience – or to remember and learn.
THE STUDY
In their study, the team of scientists noticed that the jellyfish can actually assess distance and make decisions.
“Our experiments show that contrast – how dark the root is in relation to the water – is used by the jellyfish to assess distances to roots, which allows them to swim away at just the right moment,” Prof. Garm said.
“Even more interesting is that the relationship between distance and contrast changes on a daily basis due to rainwater, algae and wave action.”
He noted that the creatures actually learn about as quickly as advanced animals like fruit flies and mice.
The findings break with previous scientific perceptions of what animals with simple nervous systems are capable of.
Prof. Garm said: “For fundamental neuroscience, this is pretty big news.
“It provides a new perspective on what can be done with a simple nervous system.
“This suggests that advanced learning may have been one of the most important evolutionary benefits of the nervous system from the very beginning.”
The team said the discovery has given them unique opportunities to study the precise changes that occur in a nerve cell when it is involved in advanced learning.
“We are now in the process of trying to pinpoint exactly which cells are involved in learning and memory formation,” Prof. Garm said.
“Upon doing so, we will be able to go in and look at what structural and physiological changes occur in the cells as learning takes place.”
