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Loving, Fighting, Peeing: The Sex Lives of Crayfish

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When I'm not blogging for mental_floss, I can usually be found wearing bright orange rubber pants and gutting, cutting and selling fish at my local Whole Foods (and winning awards for it). Sometimes, my two worlds collide and I find some scientific research involving my ocean-dwelling friends that begs for a blog post. This is one of those times.


Let's pretend, all evidence to the contrary aside, that I am a beautiful woman and I want to have children, right here and right now. What do you think is the best way to go about communicating that to men? Make eyes at them from across the room? Approach and aggressively flirt?


If I were a lady crayfish (crawfish, crawdad, mudbug, whatever you prefer to call them), my plan of action would be to urinate all over the place and start throwing punches.

Female crayfish take "playing hard to get" to a whole new level. Naturally, they want the strongest, fittest mates available to produce exceptional offspring. But crayfish are in a tough spot when it comes to discerning the fitness of potential mates. Simply checking the guys out doesn't provide much info, and chemical cues aren't always reliable. So the simplest and best way for a female to find the best mate is to test males in claw-to-claw combat herself.

How does she get the ball rolling? By peeing.

In some animals, the female initiates mating with chemical stimuli, informing suitors of her receptivity to sex. In crayfish, these stimuli happen to be in the urine. Fiona Berry and Thomas Breithaupt from the University of Hull recently published the results of a study on these urine-based chemical signals. In their experiment, male and female American signal crayfish (Pacifastacus leniusculus) were introduced to each other in a tank after being blindfolded (to exclude visual disturbance from the researchers) and injected with a fluorescent dye that accumulated in the bladder (to visualize urine).

Berry and Breithaupt found that under normal conditions (well, except for the blindfolds), the females would urinate to attract the males and then respond aggressively when they approached. The females would give up the fight only if a male was able to flip her over and deposit his sperm. When females were kept from releasing urine (by the blocking of the nephropores), though, no mating behavior was observed.

Artificial introduction of female urine, via a syringe placed in the tank, re-established normal mating attempts, demonstrating that there is a sex-specific component in the females' urine that both signals aggression and elicits mating behavior (males also use urine to signal aggression when fighting other males). The mixed aggro-sexual message that the urine communicates should, the researchers say, favor strong, high-quality males.

Aside from making our own sex lives seem normal in comparison, the lessons learned from this study could aid the UK in its battle against the signal crayfish, which is an invasive species in English rivers and carries a fungus that's lethal to the country's native white clawed crayfish (Austropotamobius torrentium).

Citation: Berry, F. and Breithaupt, T. (2010). "To signal or not to signal? Chemical communication by urine-borne signals mirrors sexual conflict in crayfish." BMC Biology 8:25. DOI:10.1186/1741-7007-8-25

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A Simple Way to Charge Your iPhone in 5 Minutes
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Spotting the “low battery” notification on your phone is usually followed by a frantic search for an outlet and further stress over the fact that you may not have time for a full charge. On iPhones, plugging your device into the wall for five minutes might result in only a modest increase of about three percent or so. But this tip from Business Insider Tech may allow you to squeeze out a little more juice.

The trick? Before charging, put your phone in Airplane Mode so that you reduce the number of energy-sucking tasks (signal searching, fielding incoming communications) your device will try and perform.

Next, take the cover off if you have one (the phone might be generating extra heat as a result). Finally, try to use an iPad adapter, which has demonstrated a faster rate of charging than the adapter that comes with your iPhone.

Do that and you’ll likely double your battery boost, from about three to six percent. It may not sound like much, but that little bit of extra juice might keep you connected until you’re able to plug it in for a full charge.

[h/t Business Insider Tech]

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Trying to Save Money? Avoid Shopping on a Smartphone
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Today, Americans do most of their shopping online—but as anyone who’s indulged in late-night retail therapy likely knows, this convenience often can come with an added cost. Trying to curb expenses, but don't want to swear off the convenience of ordering groceries in your PJs? New research shows that shopping on a desktop computer instead of a mobile phone may help you avoid making foolish purchases, according to Co. Design. Ying Zhu, a marketing professor at the University of British Columbia-Okanagan, recently led a study to measure how touchscreen technology affects consumer behavior. Published in the Journal of Retailing and Consumer Services, her research found that people are more likely to make more frivolous, impulsive purchases if they’re shopping on their phones than if they’re facing a computer monitor. Zhu, along with study co-author Jeffrey Meyer of Bowling Green State University, ran a series of lab experiments on student participants to observe how different electronic devices affected shoppers’ thinking styles and intentions. Their aim was to see if subjects' purchasing goals changed when it came to buying frivolous things, like chocolate or massages, or more practical things, like food or office supplies. In one experiment, participants were randomly assigned to use a desktop or a touchscreen. Then, they were presented with an offer to purchase either a frivolous item (a $50 restaurant certificate for $30) or a useful one (a $50 grocery certificate for $30). These subjects used a three-point scale to gauge how likely they were to purchase the offer, and they also evaluated how practical or frivolous each item was. (Participants rated the restaurant certificate to be more indulgent than the grocery certificate.) Sure enough, the researchers found that participants had "significantly higher" purchase intentions for hedonic (i.e. pleasurable) products when buying on touchscreens than on desktops, according to the study. On the flip side, participants had significantly higher purchase intentions for utilitarian (i.e. practical) products while using desktops instead of touchscreens. "The playful and fun nature of the touchscreen enhances consumers' favor of hedonic products; while the logical and functional nature of a desktop endorses the consumers' preference for utilitarian products," Zhu explains in a press release. The study also found that participants using touchscreen technology scored significantly higher on "experiential thinking" than subjects using desktop computers, whereas those with desktop computers demonstrated higher scores for rational thinking. “When you’re in an experiential thinking mode, [you crave] excitement, a different experience,” Zhu explained to Co. Design. “When you’re on the desktop, with all the work emails, that interface puts you into a rational thinking style. While you’re in a rational thinking style, when you assess a product, you’ll look for something with functionality and specific uses.” Zhu’s advice for consumers looking to conserve cash? Stow away the smartphone when you’re itching to splurge on a guilty pleasure. [h/t Fast Company]

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