Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Deep-sea squid can 'jettison arms' as defensive tactic

03.08.2012
A postdoctoral researcher at the University of Rhode Island has observed a never-before-seen defensive strategy used by a small species of deep-sea squid in which the animal counter-attacks a predator and then leaves the tips of its arms attached to the predator as a distraction.

Stephanie Bush said that when the foot-long octopus squid (Octopoteuthis deletron) found deep in the northeast Pacific Ocean "jettisons its arms" in self-defense, the bioluminescent tips continue to twitch and glow, creating a diversion that enables the squid to escape from predators.

"If a predator is trying to attack them, they may dig the hooks on their arms into the predator's skin. Then the squid jets away and leaves its arm tips stuck to the predator," explained Bush. "The wriggling, bioluminescing arms might give the predator pause enough to allow the squid to get away."

The discovery was published in the July issue of the journal Marine Ecology Progress Series.

While Bush was a graduate researcher working with the Midwater Ecology Lab at the Monterey Bay Aquarium Research Institute, she observed that many octopus squid had arms of different lengths. Scientists had speculated that they may release their arms, just as lizards can release their tails when attacked, but no one had seen it happen. Using a remotely operated vehicle in the Monterey Bay Submarine Canyon off the coast of California, Bush poked at a squid with a bottlebrush.

"The very first time we tried it, the squid spread its arms wide and it was lighting up like fireworks," she said. "It then came forward and grabbed the bottlebrush and jetted backwards, leaving two arms on the bottlebrush. We think the hooks on its arms latched onto the bristles of the brush, and that was enough for the arms to just pop off."

The squid are able to re-grow their missing arms.

"There is definitely an energy cost associated with this behavior, but the cost is less than being dead," Bush said.

In further experiments, Bush found that some octopus squid appeared hesitant to sacrifice their limbs, but some did so after being prodded several times. When she provoked seven other squid species similarly, none dropped their arm tips.

Bush's research on squid began in 2003 when she decided to investigate the assumptions that some scientists had made about deep-sea animals.

"Scientists had assumed that squid living in the deep-sea would not release ink as a defensive measure, but all the species I've observed did release ink," she said. "They assumed that because they're in the dark all day every day that they're not doing the same things that shallow water squids are doing. They also assumed that deep-sea squid don't change color because of the dark, but they do."

The URI scientist's current research focuses on a tiny squid that lives in the Gulf of California that migrates every day from the dark depths where there is little oxygen to the surface waters to feed. She is examining their oxygen consumption rates and how increasing water temperatures will affect their survival.

"They're a really abundant species in the Gulf, so presumably if they are that abundant, they must be feeding on lots of different things and there must be lots of things feeding on them," Bush said. "They could be very important to the health of the ecosystem."

Todd McLeish | EurekAlert!
Further information:
http://www.uri.edu

More articles from Ecology, The Environment and Conservation:

nachricht Bioinvasion on the rise
15.02.2017 | Universität Konstanz

nachricht Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>