The brainless Caribbean box jellyfish can remember past experiences using "advance learning" skills, according to a new study led by scientists from Denmark and Germany.
The findings suggested that the invertebrate animal can also alter or change their behavior based on these experiences, a unique and unprecedented ability of its kind.
The research team concluded that the box jellyfish (Tripedalia cystophora) species is capable of "associative learning."
This learning ability is based on the combination of visual and mechanical stimuli, which the marine creature uses to recall this past information.
The findings are significant since it has been thought for a long time that jellyfish are mindless creatures with no signs of being sentient.
Now, the discovery paves the way for further understanding of the complex biological systems possessed by the gelatinous sea jellies in the world.
Caribbean Box Jellyfish
In a new study published in the journal Current Biology on September 22, researchers acknowledged that associative learning, which pertains to classical or operant conditioning, has never been unanimously linked with animals outside bilaterians (such as vertebrates, arthropods, or mollusks).
In addition, they highlighted that such learning is crucial for the survival of the majority of animals.
In previous research, obstacle avoidance is one of the several behaviors that guide box jellyfish from harm.
According to the Current Biology study, this trait, officially called obstacle avoidance behavior (OAB) is a species-specific type of defense mechanism for T. cystophora.
This observation is made possible after the team found that the rhopalial nervous is the learning center of the brainless Caribbean box jellyfish.
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Jellyfish Evolution
Often deemed as alien-like creatures, jellyfish are common across the world's oceans, where they can also be spotted in shallow waters depending at the time of the year.
However, they are as ancient than previously thought.
In fact, jellyfish have been around Earth for more than 500 million years, making them older than non-avian dinosaurs that perished from a planet-killing space rock 65 million years ago.
According to the organization Orlando Science Center, the oldest-known jellyfish fossils were found in Utah, dating back 505 million years ago, highlighting that ancient jellyfish appeared more than 250 million years even before the first dinosaurs.
Despite their long existence, the jellyfish lineage has relatively evolved less compared with other animals, especially mammals.
Scientists said that the modern day jellyfish evolved a long time ago, but assert they are likely smarter than previously thought.
Aside from the learning capabilities of the Caribbean box jellyfish, other members of the free-swimming marine animals have become candidates for the centuries-old quest for immortality.
In 2022, scientists from Spain unraveled the genetic code of the "immortal jellyfish" which is capable of reversing aging, based on a study published in PNAS by researchers at the University of Oviedo and their colleagues.
Scientifically known as Turritopsis dohrnii, the secrets of the immortal jellyfish could provide new clues when it comes to human aging, according to reports.
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