These jellyfish aren't just drifters

January 22, 2015

Jellyfish might look like mere drifters, but some of them have a remarkable ability to detect the direction of ocean currents and to swim strongly against them, according to new evidence in free-ranging barrel-jellyfish reported in the Cell Press journal Current Biology on January 22.

"Detecting ocean currents without fixed visual reference points is thought to be close to impossible and is not seen, for example, in lots of migrating vertebrates including birds and turtles," says Graeme Hays of Deakin University in Australia.

"Jellyfish are not just bags of jelly drifting passively in the oceans," he adds. "They are incredibly advanced in their orientation abilities."

The researchers tracked the movements of the jellyfish with GPS loggers and used GPS-tracked floats to record the current flows. They also directly observed the swimming direction of large numbers of jellyfish at the surface of the ocean.

The data show that jellyfish can actively swim at counter-current in response to drift, the researchers report. Their model of the jellyfishes' behavior, together with ocean currents, helps to explain how jellyfish are able to form blooms including hundreds to millions of individuals for periods up to several months.

It's not yet clear exactly how the jellyfish figure out which way to go. Fossette and Hays say it's possible that the animals detect current shear across their body surface, or they may indirectly assess the direction of drift using other cues, such as the Earth's magnetic field or infrasound.

Understanding the distribution of jellyfish in the open ocean may be practically useful for predicting and avoiding troublesome jellyfish blooms, especially if it turns out that the findings in barrel-jellyfish apply to other species. While jellyfish do play an important role in ocean ecosystems as prey for leatherback sea turtles and other animals, Hays notes, they can also clog fishing nets and sting beachgoers.

"Now that we have shown this remarkable behavior by one species, we need to see how broadly it applies to other species of jellyfish," Hays says. "This will allow improved management of jellyfish blooms."
-end-
Current Biology, Fossette et al.: "Current-oriented swimming by jellyfish and its role in bloom maintenance"

Current Biology, published by Cell Press, is a bimonthly journal that features papers across all areas of biology. Current Biology strives to foster communication across fields of biology, both by publishing important findings of general interest and through highly accessible front matter for non-specialists. For more information please visit http://www.cell.com/current-biology. To receive media alerts for Current Biology or other Cell Press journals, contact press@cell.com.

Cell Press

Related Magnetic Field Articles from Brightsurf:

Investigating optical activity under an external magnetic field
A new study published in EPJ B by Chengping Yin, Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China, aims to derive an analytical model of optical activity in black phosphorous under an external magnetic field.

Magnetic field and hydrogels could be used to grow new cartilage
Instead of using synthetic materials, Penn Medicine study shows magnets could be used to arrange cells to grow new tissues

Magnetic field with the edge!
This study overturns a dominant six-decade old notion that the giant magnetic field in a high intensity laser produced plasma evolves from the nanometre scale.

Global magnetic field of the solar corona measured for the first time
An international team led by Professor Tian Hui from Peking University has recently measured the global magnetic field of the solar corona for the first time.

Magnetic field of a spiral galaxy
A new image from the VLA dramatically reveals the extended magnetic field of a spiral galaxy seen edge-on from Earth.

How does Earth sustain its magnetic field?
Life as we know it could not exist without Earth's magnetic field and its ability to deflect dangerous ionizing particles.

Scholes finds novel magnetic field effect in diamagnetic molecules
The Princeton University Department of Chemistry publishes research this week proving that an applied magnetic field will interact with the electronic structure of weakly magnetic, or diamagnetic, molecules to induce a magnetic-field effect that, to their knowledge, has never before been documented.

Origins of Earth's magnetic field remain a mystery
The existence of a magnetic field beyond 3.5 billion years ago is still up for debate.

New research provides evidence of strong early magnetic field around Earth
New research from the University of Rochester provides evidence that the magnetic field that first formed around Earth was even stronger than scientists previously believed.

Massive photons in an artificial magnetic field
An international research collaboration from Poland, the UK and Russia has created a two-dimensional system -- a thin optical cavity filled with liquid crystal -- in which they trapped photons.

Read More: Magnetic Field News and Magnetic Field Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.