Contact Information:
Sophia Grein
sophia.grein@springer.com
49-622-148-78414
Springer



Kredyty mieszkaniowe Kredyty mieszkaniowe

Sprawdź aktualny ranking najlepszych kredytów mieszkaniowych w Polsce - atrakcyjne kredytowanie nieruchomości.

PRESS-NEWS.org - Press Release Distribution
FREE PRESS RELEASES DISTRIBUTION
RSS - Press News Release
Add Press Release

Reversal of the black widow myth

Some male spiders prefer to eat old females rather than mate with them


2013-05-06
(Press-News.org) VIDEO: Reverse cannibalism: Some male spiders prefer to eat old females rather than mate with them.
Click here for more information.

The Black Widow spider gets its name from the popular belief that female spiders eat their male suitors after mating. However, a new study has shown that the tendency to consume a potential mate is also true of some types of male spider. The study by Lenka Sentenska and Stano Pekar from Masaryk University in the Czech Republic finds that male spiders of the Micaria sociabilis species are more likely to eat the females than be eaten. The paper, published in Springer's journal Behavioral Ecology and Sociobiology, outlines possible reasons for this behavior.

In nature, female choice of mate is commonly seen as the overriding factor affecting male mating success. Sexual cannibalism is a form of female mate choice with low-quality mates more likely to be cannibalized. However, there is not as much evidence about how males may sometimes dictate the choice of partner. The researchers suggest that in the Micaria sociabilis species, reverse cannibalism seen may be a type of male mate choice.

The researchers collected male and female Micaria sociabilis spiders over a two-year period and studied their behavior by mixing males and females of the species at different time points. All spiders were well fed to discount cannibalism due to hunger. The authors observed what happened when they paired young adult male spiders with single female spiders either from the same generation (young female) or from another generation (old female). By pairing males with females of different size, age and mating status, the researchers hoped to be able to identify whether the reversed form of sexual cannibalism was an adaptive mechanism for male mate choice.

Their study found that cannibalism took place early after the first contact and before any mating took place. The researchers also observed that reverse cannibalism differed significantly, depending on what month it was – most of the incidences were in July. Males from the summer generation tended to be bigger than males from the spring generation and they were more cannibalistic. This would suggest that male aggression may be related to male size.

The authors noted that the highest frequency of reverse cannibalism occurred when these larger, young males from the summer generation met old females from the previous spring generation. This suggests they may have based their choice on female age. Female body size, even though considered to be a sign of quality, did not affect rates of cannibalism. The authors also noted no difference in male cannibalization of females who had previously mated or virgin females. This evidence demonstrates that in some species and some cases, the males make a very clear choice about who they will mate with.

The authors remark: "Our study provides an insight into an unusual mating system, which differs significantly from the general model. Even males may choose their potential partners and apparently, in some cases, they can present their choice as extremely as females do by cannibalizing unpreferred mates."

### Reference: Sentenska, L. and Pekar, S. (2013), Mate with young, kill old: reverse sexual cannibalism and male mate choice in the spider Micaria sociabilis (Araneae: Gnaphosidae), Behavioral Ecology and Sociobiology. DOI 10.1007/s00265-013-1538-1

The full-text article, photos and a video-clip are available to journalists on request.

ELSE PRESS RELEASES FROM THIS DATE:

Possible treatment for serious blood cancer

2013-05-06
A single antibody could be the key to treating multiple myeloma, or cancer of the blood, currently without cure or long-term treatment. "We tested the antibody in various ways, including on tumour cells from myeloma patients that have been transplanted into mice. The tests showed that the antibody is able to destroy myeloma cells", explains Markus Hansson, a researcher at Lund University in Sweden. Using a 'biological library' of thousands of antibodies from the company BioInvent in Lund, the team singled out antibody BI-505, shown to have a powerful effect on the ...

Researchers reveal new more precise method of performing electroconvulsive therapy

2013-05-06
Philadelphia, PA, May 6, 2013 - Electroconvulsive therapy (ECT) is the most effective acute treatment for severe major depression. However, even with newer forms of ECT, there remains a significant risk of adverse cognitive effects, particularly memory problems. Current theories hold that the regions that need to be stimulated to treat the depression (the cortex) are different and separate from the regions that result in memory problems (the hippocampus and temporal lobes). Theoretically, a more precise form of ECT could have all of the efficacy and few or none of the ...

Columbia engineers manipulate a buckyball by inserting a single water molecule

2013-05-06
New York, NY—May 3, 2013—Columbia Engineering researchers have developed a technique to isolate a single water molecule inside a buckyball, or C60, and to drive motion of the so-called "big" nonpolar ball through the encapsulated "small" polar H2O molecule, a controlling transport mechanism in a nanochannel under an external electric field. They expect this method will lead to an array of new applications, including effective ways to control drug delivery and to assemble C60-based functional 3D structures at the nanoscale level, as well as expanding our understanding of ...

The nocebo effect: Media reports may trigger symptoms of a disease

2013-05-06
Media reports about substances that are supposedly hazardous to health may cause suggestible people to develop symptoms of a disease even though there is no objective reason for doing so. This is the conclusion of a study of the phenomenon known as electromagnetic hypersensitivity. Those affected report experiencing certain symptoms on exposure to electromagnetic waves, such as those emitted by cell phones, and these take the form of physical reactions. With the help of magnetic resonance imaging, it has been demonstrated that the regions of the brain responsible for pain ...

Do-it-yourself invisibility with 3-D printing

2013-05-06
DURHAM, N.C. – Seven years ago, Duke University engineers demonstrated the first working invisibility cloak in complex laboratory experiments. Now it appears creating a simple cloak has become a lot simpler. "I would argue that essentially anyone who can spend a couple thousand dollars on a non-industry grade 3-D printer can literally make a plastic cloak overnight," said Yaroslav Urzhumov, assistant research professor in electrical and computer engineering at Duke's Pratt School of Engineering. Three-dimensional printing, technically known as stereolithographic fabrication, ...

A KAIST research team developed in vivo flexible large scale integrated circuits

2013-05-06
Daejeon, Republic of Korea, May 6th, 2013–-A team led by Professor Keon Jae Lee from the Department of Materials Science and Engineering at KAIST has developed in vivo silicon-based flexible large scale integrated circuits (LSI) for bio-medical wireless communication. Silicon-based semiconductors have played significant roles in signal processing, nerve stimulation, memory storage, and wireless communication in implantable electronics. However, the rigid and bulky LSI chips have limited uses in in vivo devices due to incongruent contact with the curvilinear surfaces of ...

Occupational data in medical billing records could prevent workplace injuries

2013-05-06
PHILADELPHIA (May 6, 2013)— A subtle change to hospital data collection policies could make a big difference in preventing occupational health and safety hazards, according to workplace safety researchers at the Drexel University School of Public Health. In a new article published in the Journal of Occupational and Environmental Medicine, the researchers call on industry, occupational medicine and public health communities to support a change to data collection methods to include industry and occupation data. Every year, nearly four million Americans suffer a workplace ...

More than a good eye: Carnegie Mellon robot uses arms, location and more to discover objects

2013-05-06
PITTSBURGH—A robot can struggle to discover objects in its surroundings when it relies on computer vision alone. But by taking advantage of all of the information available to it — an object's location, size, shape and even whether it can be lifted — a robot can continually discover and refine its understanding of objects, say researchers at Carnegie Mellon University's Robotics Institute. The Lifelong Robotic Object Discovery (LROD) process developed by the research team enabled a two-armed, mobile robot to use color video, a Kinect depth camera and non-visual information ...

Commands from the matrix

2013-05-06
Environment moulds behaviour - and not just that of people in society, but also at the microscopic level. This is because, for their function, neurons are dependent on the cell environment, the so-termed extracellular matrix. Researchers at the Ruhr-Universität have found evidence that this complex network of molecules controls the formation and activity of the neuronal connections. The team led by Dr. Maren Geißler und Prof. Andreas Faissner from the Department of Cell Morphology and Molecular Neurobiology reports in the "Journal of Neuroscience" in collaboration with ...

Weight gain linked with personality trait changes

2013-05-06
People who gain weight are more likely to give in to temptations but also are more thoughtful about their actions, according to a new study published in Psychological Science, a journal of the Association for Psychological Science. To understand how fluctuations in body weight might relate to personality changes, psychological scientist Angelina Sutin of the Florida State University College of Medicine and colleagues at the National Institutes of Health (NIH) examined data from two large-scale longitudinal studies of Baltimore residents. "We know a great deal about ...

LAST 30 PRESS RELEASES:

How your brain decides blame and punishment -- and how it can be changed

Uniquely human brain region enables punishment decisions

Pinpointing punishment

Chapman University publishes research on attractiveness and mating

E-cigarettes: Special issue from Nicotine & Tobacco Research

Placental problems in early pregnancy associated with 5-fold increased risk of OB & fetal disorders

UT study: Invasive brood parasites a threat to native bird species

Criminals acquire guns through social connections

Restoring ocean health

Report: Cancer remains leading cause of death in US Hispanics

Twin study suggests genetic factors contribute to insomnia in adults

To be fragrant or not: Why do some male hairstreak butterflies lack scent organs?

International team discovers natural defense against HIV

Bolivian biodiversity observatory takes its first steps

Choice of college major influences lifetime earnings more than simply getting a degree

Dominant strain of drug-resistant MRSA decreases in hospitals, but persists in community

Synthetic biology needs robust safety mechanisms before real world application

US defense agencies increase investment in federal synthetic biology research

Robots help to map England's only deep-water Marine Conservation Zone

Mayo researchers identify protein -- may predict who will respond to PD-1 immunotherapy for melanoma

How much water do US fracking operations really use?

New approach to mammograms could improve reliability

The influence of citizen science grows despite some resistance

Unlocking secrets of how fossils form

What happens on the molecular level when smog gets into the lungs?

Using ultrasound to clean medical instruments

Platinum and iron oxide working together get the job done

Tiny silica particles could be used to repair damaged teeth, research shows

A quantum lab for everyone

No way? Charity's logo may influence perception of food in package

[Press-News.org] Reversal of the black widow myth
Some male spiders prefer to eat old females rather than mate with them
Press-News.org is a service of DragonFly Company. All Rights Reserved.
Issuers of news releases are solely responsible for the accuracy of their content.