Nav: Home

Electric eels leap to deliver painful, Taser-like jolt

September 14, 2017

The electric eel has always been noted for its impressive ability to shock and subdue its prey. It's recently become clear that electric eels also use a clever trick to deliver an intense, Taser-like jolt to potential predators: they leap from the water to target threatening animals, humans included, above water. Now, a researcher reporting in Current Biology on September 14 has measured (and experienced) just how strong that jolt can be.

Those stunning leaps make for a more painful experience because they prevent the eels' electrical discharges from weakening as they dissipate through the water.

"We've known these animals give off a huge amount of electricity, and everybody thought that was really amazing," says Kenneth Catania of Vanderbilt University. "But they aren't just simple animals that go around shocking stuff. They've evolved to produce stronger and stronger electrical discharges, and in concert they've evolved these behaviors to more efficiently use them."

Catania earlier showed that the eels curl their bodies around their prey to double the power of their electrical discharge. In the course of his studies, he noticed something else unusual. If he used an electrically conductive, metal net to scoop up electric eels in his lab, the animals leapt from the water to attack the net.

Catania realized he had accidentally imitated a predatory attack on his eels in shallow water. But, at first, he was "just confused" by their behavior. Why didn't they simply swim away? He soon realized the leaping might help the eels to effectively target a would-be predator and intensify the shock.

In fact, electric eels' leaping behavior had been described by Alexander von Humboldt way back in the 1800s. Humboldt claimed to have witnessed a dramatic battle between electric eels and horses in the Amazon. But, Catania says, "No one really necessarily believed it, or if they did, they thought it was just kind of weird." Whatever they thought, it was more or less forgotten.

To understand the dynamics of the electrical circuit created when an eel contacts another animal, Catania developed an apparatus to accurately measure the strength of the electric current through a human arm when the electric eels leapt in attack. Catania put that apparatus to use with his own arm and a relatively small, and therefore less powerful, eel.

As reported in the new study, the electrical current delivered by the eel peaked at 40-50 milliamps. That's more than enough to cause a person or animal considerable pain, but not enough to actually hurt them. In a video, one can see Catania's arm reflexively pull back, an involuntary reaction similar to what would happen if you touched a hot stove.

"It's impressive that a little eel could deliver that much electricity," Catania says. Of course, they have good reason as they may encounter crocodiles, predatory cats, and "who knows what else," he adds. "We don't know the main driver of the behavior, but they need to deter predators, and I can tell you it's really good at that. I can't imagine an animal that had received this [jolt] sticking around."

Now that he's been able to measure the strength of the electrical current, Catania says he can solve the rest of the circuit. That means it's now possible to estimate the power of a shock delivered by eels of various size or under different circumstances. It turns out the findings are relevant to humans, too. Catania notes that a YouTube video that recently surfaced and went viral shows a fisherman being shocked by a leaping electric eel in the Amazon.

When Catania first saw that footage, it surprised him. But, he now realizes, it's something that's "probably happened a lot." The only difference in the recent case is that someone managed to successfully capture it on video. Now, after voluntarily receiving more shocks in his lab than he cares to recount, Catania has, too.
-end-
This work was supported by the National Science Foundation.

Current Biology, Catania, K.: "Power Transfer to a Human during an Electric Eel's Shocking Leap" http://www.cell.com/current-biology/fulltext/S0960-9822(17)31072-2

Current Biology (@CurrentBiology), 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. Visit: http://www.cell.com/current-biology. To receive Cell Press media alerts, contact press@cell.com.

Cell Press

Related Behavior Articles:

Religious devotion as predictor of behavior
'Religious Devotion and Extrinsic Religiosity Affect In-group Altruism and Out-group Hostility Oppositely in Rural Jamaica,' suggests that a sincere belief in God -- religious devotion -- is unrelated to feelings of prejudice.
Brain stimulation influences honest behavior
Researchers at the University of Zurich have identified the brain mechanism that governs decisions between honesty and self-interest.
Brain pattern flexibility and behavior
The scientists analyzed an extensive data set of brain region connectivity from the NIH-funded Human Connectome Project (HCP) which is mapping neural connections in the brain and makes its data publicly available.
Butterflies: Agonistic display or courtship behavior?
A study shows that contests of butterflies occur only as erroneous courtships between sexually active males that are unable to distinguish the sex of the other butterflies.
Sedentary behavior associated with diabetic retinopathy
In a study published online by JAMA Ophthalmology, Paul D.
Curiosity has the power to change behavior for the better
Curiosity could be an effective tool to entice people into making smarter and sometimes healthier decisions, according to research presented at the annual convention of the American Psychological Association.
Campgrounds alter jay behavior
Anyone who's gone camping has seen birds foraging for picnic crumbs, and according to new research in The Condor: Ornithological Applications, the availability of food in campgrounds significantly alters jays' behavior and may even change how they interact with other bird species.
A new tool for forecasting the behavior of the microbiome
A team of investigators from Brigham and Women's Hospital and the University of Massachusetts have developed a suite of computer algorithms that can accurately predict the behavior of the microbiome -- the vast collection of microbes living on and inside the human body.
Is risk-taking behavior contagious?
Why do we sometimes decide to take risks and other times choose to play it safe?
Neural connectivity dictates altruistic behavior
A new study suggests that the specific alignment of neural networks in the brain dictates whether a person's altruism was motivated by selfish or altruistic behavior.

Related Behavior Reading:

Behave: The Biology of Humans at Our Best and Worst
by Robert M. Sapolsky (Author)

The New York Times bestseller

“It’s no exaggeration to say that Behave is one of the best nonfiction books I’ve ever read.” —David P. Barash, The Wall Street Journal

"It has my vote for science book of the year.” Parul Sehgal, The New York Times

"Hands-down one of the best books I’ve read in years. I loved it." —Dina Temple-Raston, The Washington Post

Named a Best Book of the Year by The Washington Post and The Wall... View Details


Behavior: The Forgotten Curriculum -- An RTI Approach for Nurturing Essential Life Skills (Transform Your Differentiated Instruction, Assessment, and Behavior-Management Strategies)
by Chris Weber (Author)

To fully prepare students for college, careers, and life, it is essential for educators to nurture students' behavioral skills along with their academic skills. With Behavior: The Forgotten Curriculum, you will learn how to employ the most effective behavioral and social skills activities for your particular class and form unique relationships with each and every learner. Through this personalized classroom behavior-management approach, you can anticipate potential problem areas and confidently respond to students in need of intensive and differentiated supports.

Use... View Details


The Behavior Code: A Practical Guide to Understanding and Teaching the Most Challenging Students
by Jessica Minahan (Author), Nancy Rappaport MD (Author)

Based on a collaboration dating back nearly a decade, the authors—a behavioral analyst and a child psychiatrist—reveal their systematic approach for deciphering causes and patterns of difficult behaviors and how to match them with proven strategies for getting students back on track to learn.

The Behavior Code includes user-friendly worksheets and other helpful resources. View Details


Subliminal: How Your Unconscious Mind Rules Your Behavior
by Leonard Mlodinow (Author)

From the bestselling author of The Drunkard’s Walk and coauthor of The Grand Design (with Stephen Hawking), a startling and eye-opening examination of how the unconscious mind shapes our experience of the world.
 
Winner of the 2013 PEN/E.O. Wilson Literary Science Writing Award
 
Over the past two decades of neurological research, it has become increasingly clear that the way we experience the world--our perception, behavior, memory, and social judgment--is largely driven by the mind's subliminal processes and not by the conscious ones, as we... View Details


The Good News About Bad Behavior: Why Kids Are Less Disciplined Than Ever—And What to Do About It
by Katherine Reynolds Lewis (Author)

The current model of parental discipline is as outdated as a rotary phone.
Why don't our kids do what we want them to do? Parents often take the blame for misbehavior, but this obscures a broader trend: in our modern, highly connected age, children have less self-control than ever. About half of the current generation of children will develop a mood or behavioral disorder or a substance addiction by age eighteen. Contemporary kids need to learn independence and responsibility, yet our old ideas of punishments and rewards are preventing this from happening.
To stem this growing... View Details


The Survival Guide for Kids with Behavior Challenges: How to Make Good Choices and Stay Out of Trouble
by Thomas McIntyre Ph.D. (Author)

Many kids and teens have challenges when it comes to behavior. In this revised edition of his time-tested book, Thomas McIntyre provides up-to-date information, practical strategies, and sound advice to help kids learn to make smarter choices, make and keep friends, get along with teachers, take responsibility for their actions, work toward positive change, and enjoy the results of their better behavior. New to this edition are an “Are you ready to change?” quiz, updated glossary and resources, and a fresh organization and design. This is a book for any young person who needs help with... View Details


How to Reach and Teach Children with Challenging Behavior (K-8): Practical, Ready-to-Use Interventions That Work
by Kaye Otten (Author), Jodie Tuttle (Author)

Interventions for students who exhibit challenging behavior

Written by behavior specialists Kaye Otten and Jodie Tuttle--who together have 40 years of experience working with students with challenging behavior in classroom settings--this book offers educators a practical approach to managing problem behavior in schools. It is filled with down-to-earth advice, ready-to-use forms, troubleshooting tips, recommended resources, and teacher-tested strategies. Using this book, teachers are better able to intervene proactively, efficiently, and effectively with students exhibiting behavior... View Details


Behavior Solutions for the Inclusive Classroom: A Handy Reference Guide that Explains Behaviors Associated with Autism, Asperger's, ADHD, Sensory Processing Disorder, and other Special Needs
by Beth Aune (Author), Beth Burt (Author), Peter Gennaro (Author)

WHY won't he stay in his seat?
WHY does she flap her hands?
And WHAT should I do?
As inclusion becomes the norm in general education, teachers are faced with behaviors they have never seen before. Special needs educators may recognize the telltale symptom of a sensory need or a textbook case of an avoidance behavior, but this is all new territory for the General-Ed crowd!
Written by Director of Special Education Peter Gennaro, occupational therapist Beth Aune, and special needs mom and advocate Beth Burt, this book illuminates possible causes of those mysterious behaviors,... View Details


The Dialectical Behavior Therapy Skills Workbook: Practical DBT Exercises for Learning Mindfulness, Interpersonal Effectiveness, Emotion Regulation & ... Tolerance (New Harbinger Self-Help Workbook)
by Matthew McKay (Author), Jeffrey C. Wood (Author), Jeffrey Brantley (Author)

A Clear and Effective Approach to Learning DBT Skills

First developed for treating borderline personality disorder, dialectical behavior therapy (DBT) has proven effective as treatment for a range of other mental health problems, especially for those characterized by overwhelming emotions. Research shows that DBT can improve your ability to handle distress without losing control and acting destructively. In order to make use of these techniques, you need to build skills in four key areas-distress tolerance, mindfulness, emotion regulation, and interpersonal... View Details


Ethics for Behavior Analysts, 3rd Edition
by Jon Bailey (Author), Mary Burch (Author)

This fully-updated third edition of Jon Bailey and Mary Burch’s bestselling Ethics for Behavior Analysts is an invaluable guide to understanding and implementing the newly-revised Behavior Analyst Certification Board (BACB) Professional and Ethical Compliance Code. Featured in this new edition are case studies drawn from the author’s real-world practice with hints to guide readers toward the ethical ‘solution’ and revised chapters, including how this new edition evolved alongside the revised Code and tips for succeeding in your first job as a certified behavior analyst. The... View Details

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

The Person You Become
Over the course of our lives, we shed parts of our old selves, embrace new ones, and redefine who we are. This hour, TED speakers explore ideas about the experiences that shape the person we become. Guests include aerobatics pilot and public speaker Janine Shepherd, writers Roxane Gay and Taiye Selasi, activist Jackson Bird, and fashion executive Kaustav Dey.
Now Playing: Science for the People

#478 She Has Her Mother's Laugh
What does heredity really mean? Carl Zimmer would argue it's more than your genes along. In "She Has Her Mother’s Laugh: The Power, Perversions, and Potential of Heredity", Zimmer covers the history of genetics and what kinship and heredity really mean when we're discovering how to alter our own DNA, and, potentially, the DNA of our children.