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9 Animals That Use Electricity

We all know about the fish-zapping powers of the electric eel, but what about the platypus, the dolphin, or the hornet?

1. STARGAZER (FAMILY URANOSCOPIDAE)

A homely fish with a dreamy name, the stargazer has modified eye muscles that can emit an electric charge. The shock isn't strong enough to stun the fish's prey, but it might distract or confuse them, giving the stargazer a chance to pounce. Scientists have hypothesized that it might also startle potential predators long enough for the stargazer to get away.

2. GUIANA DOLPHIN (SOTALIA GUIANENSIS)

Where dogs and cats have whiskers, a Guiana dolphin has specialized pores called vibrissal crypts. These modified hair follicles allow the dolphin to sense electrical fields. This doesn't sound terribly useful until you consider that all of the dolphins' prey animals generate electricity in some form or another. The researchers who discovered the dolphins' electric talents have hypothesized that other marine mammals might have similar skills.

3. ORIENTAL HORNET (VESPA ORIENTALIS)

Most hornets snooze through the heat of the day, but not the oriental hornet. Curious about the insect's unusual proclivity for intense sunlight, researchers took a closer look at the hornet's exoskeleton. What they found was straight-up weird: solar panels on the hornet's body were converting sunlight into electricity. The exact purpose of the bug's juice remains to be seen, but it's unlikely the hornets would be bothering to make it if they didn't need it.

4. & 5. PLATYPUS (ORNITHORHYNCHUS ANATINUS) AND ECHIDNA (FAMILY TACHYGLOSSIDAE)

Most mammals give birth to live babies. That's kind of part of being a mammal. But the monotremes—platypuses and echidnas—want nothing to do with that messy business. They lay eggs like civilized animals, and they don't care what you think. But their disregard for normal mammal behavior doesn't stop when the egg drops. The echidna's snout and the platypus's bill are packed with sensitive cells that allow them to sense electricity. This comes in handy for hunting underwater and underground in the dark. 

6. ELECTRIC CATFISH (FAMILY MALAPTERURIDAE)

Like their cousins, the badly named electric eels (which aren't eels at all), electric catfish have organs in their heads that allow them to zap all comers with 350 volts of unpleasantness. Through the magic of the Internet, you can actually watch as this genius fish-keeper grabs his catfish "to see what happens." (Spoiler: The repeated shocks were "not comfortable at all.")

7. BUMBLEBEE (GENUS BOMBUS)

Bees are, well, busy. They don't have time to waste visiting flowers that have already been emptied by their coworkers. Fortunately, the flowers can help them out. Each blossom broadcasts a variable electrical signal, like a hotel's VACANCY sign. After a bee caller leaves, the now-sapped flower switches its field to broadcast NO VACANCY, which tells incoming bees to try some other bloom.

8. SHARKS (CLADE SELACHIMORPHA)

The shark doesn't really do anything halfway. Its ability to sense electricity is 10,000 times stronger than any other animal's. This skill is so developed that scientists call it a "sixth sense," and it might help in more ways than one. Although sharks look tough, they're in trouble, and they face huge risks from commercial fishing. Some researchers have proposed sticking big magnets or electropositive metals to fishing boats. Early studies have shown that the unusual electrical signals may give the sharks enough warning to get out of the boats' way.

9. SPIDERS (ORDER ARANEAE)

Is there nothing spiders can't do? They dance, they pounce, they purr, and some can even make music. And now, it turns out, also exploit electricity. Spiders smear their webs with a special electrostatic glue that actually allows the web to reach out and grab charged particles like water, pollen, and prey. 

Original image
Andreas Trepte via Wikimedia Commons // CC BY-SA 2.5
Climate Change Has Forced Mussels to Toughen Up
Original image
Andreas Trepte via Wikimedia Commons // CC BY-SA 2.5

Researchers writing in the journal Science Advances say blue mussels are rapidly evolving stronger shells to protect themselves against rising acid levels in sea water.

Bivalves like mussels, clams, and oysters aren’t good swimmers, and they don’t have teeth. Their hard shells are often the only things standing between themselves and a sea of dangers.

But even those shells have been threatened lately, as pollution and climate change push the ocean's carbon dioxide to dangerous levels. Too much carbon dioxide interferes with a bivalve’s ability to calcify (or harden) its shell, leaving it completely vulnerable.

A team of German scientists wondered what, if anything, the bivalves were doing to cope. They studied two populations of blue mussels (Mytilus edulis): one in the Baltic Sea, and another in the brackish waters of the North Sea.

The researchers collected water samples and monitored the mussel colonies for three years. They analyzed the chemical content of the water and the mussels’ life cycles—tracking their growth, survival, and death.

The red line across this mussel larva shows the limits of its shell growth. Image credit: Thomsen et al. Sci. Adv. 2017

Analysis of all that data showed that the two groups were living very different lives. The Baltic was rapidly acidifying—but rather than rolling over and dying, Baltic mussels were armoring up. Over several generations, their shells grew harder.

Their cousins living in the relatively stable waters of the North Sea enjoyed a cushier existence. Their shells stayed pretty much the same. That may be the case for now, the researchers say, but it definitely leaves them vulnerable to higher carbon dioxide levels in the future.

Inspiring as the Baltic mussels’ defiance might be, the researchers note that it’s not a short-term solution. Tougher shells didn’t increase the mussels’ survival rate in acidified waters—at least, not yet.

"Future experiments need to be performed over multiple generations," the authors write, "to obtain a detailed understanding of the rate of adaptation and the underlying mechanisms to predict whether adaptation will enable marine organisms to overcome the constraints of ocean acidification."

Original image
University of Adelaide
Scientists Find Potential Diabetes Drug in Platypus Venom
Original image
University of Adelaide

The future of diabetes medicine may be duck-billed and web-footed. Australian researchers have found a compound in platypus venom (yes, venom) that balances blood sugar. The team published their results in the journal Scientific Reports.

So, about that venom. The platypus (Ornithorhynchus anatinus) may look placid and, frankly, kind of goofy, but come mating season, the weaponry comes out. Male platypuses competing for female attention wrestle their opponents to the ground and kick-stab them with the venom-tipped, talon-like spurs on their back legs. It’s not a pretty sight. But it is an interesting one, especially to researchers.

Animal venoms are incredible compounds with remarkable properties—and many of them make excellent medicine. Many people with diabetes are already familiar with one of them; the drug exenatide was originally found in the spit of the venomous gila monster. Exenatide works by mimicking the behavior of an insulin-producing natural compound called Glucagon-like peptide 1 (GLP-1). The fact that the lizard has both venom and insulin-making genes is not a coincidence; many animal venoms, including the gila monster’s, induce low blood sugar in their prey in order to immobilize them.

It’s a good strategy with one flaw: GLP-1 and compounds like it break down and stop working very quickly, and people who have trouble making insulin really need their drug to keep working.

With this issue in mind, Australian researchers turned their attention to our duck-billed friends. They knew that platypuses, like people, made GLP-1 in their guts, and that platypuses, like gila monsters, make venom. The real question was how these two compounds interacted within a platypus’s body.

The researchers used chemical and genetic analysis to identify the chemical compounds in the guts and spurs of platypuses and in the guts of their cousins, the echidnas.

They found something entirely new: a tougher, more resilient GLP-1, one that breaks down differently—and more slowly—than the compounds in gila monster spit. The authors say this uber-compound is the result of a "tug of war" between GLP-1’s two uses in the gut and in venom.

"This is an amazing example of how millions of years of evolution can shape molecules and optimise their function," co-lead author Frank Gutzner of the University of Adelaide said in a statement.

"These findings have the potential to inform diabetes treatment, one of our greatest health challenges, although exactly how we can convert this finding into a treatment will need to be the subject of future research."

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