Curio Cabinet

Who are you calling a “shrimp?” The peacock mantis shrimp is legendary for its powerful punch, which can stun or injure prey in the blink of an eye. Now, researchers at Northwestern University can finally explain how these strange shrimp manage to deal such devastating blows without harming themselves, according to a paper published in Science.
 
As their name suggests, peacock mantis shrimp are striking creatures with colorful exoskeletons (though they aren’t actually true shrimp). Their most interesting feature isn’t their looks, though, it’s their unique ability to strike with their claws. Their punches move at 60 miles-per-hour, so fast that they create an imploding bubble capable of applying 1,000 times the shrimp’s own body weight onto whatever they’re punching. Usually, their victims are prey like mollusks or small crabs. Mantis shrimp punches are so powerful that they can even shatter glass. Yet, despite their diminutive size, mantis shrimp can punch over and over again without destroying themselves.
 
The exact cause of their resilience has long been a biological mystery. Now, thanks to the recent study, we know that the mantis shrimps’ secret weapon is layers of hardened chitin in their forelimbs. Chitin is the same material that makes up the shrimps' exoskeleton, and it's shaped into helix-like structures like those found in some human-engineered materials. The unique shape of the chitin layers creates a powerful dampening effect, allowing a mantis shrimp’s claws to absorb dangerous shockwaves and dissipate the energy from their punches. Researchers were able to determine this by blasting a cross-section of a mantis shrimp’s claw with laser pulses, which caused the claw to expand and cool rapidly, mimicking the conditions it would experience during a punch. Let’s hope that human boxers never get wise to this secret—things could get messy.

[Image description: An orange-and-red mantis shrimp peering out from a hole in algae-covered rocks.] Credit & copyright: Vassil, Wikimedia Commons. This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.
 

The body of a hippo, the hooves of a horse and the nose of an elephant…this is one strange looking animal! Tapirs have been making headlines lately, as an extremely rare Malayan tapir calf was recently born at the Point Defiance Zoo & Aquarium in Tacoma, Washington. Since Malayan tapirs are born with distinctive white spots and stripes on their dark fur, the baby has made quite an impression on social media. Regardless of age, tapirs are some of the most unusual animals in the world with a surprising evolutionary history.
 
There are four species of tapir alive today. All are found in Central and South America except for the Malayan tapir, which is native to southeast Asia. Malayan tapirs are also the largest species, reaching lengths of up to 8 feet and weighing up to 800 pounds. Tapirs’ most distinguishing physical feature are their noses, which, like an elephant's trunk, is prehensile, or able to grasp things. Yet, elephants aren’t tapirs’ closest living relatives. That honor goes to horses and rhinos which, along with tapirs, are members of the family Equidae (from which we get the horse-riding term “equestrian.”). Tapirs are the oldest members of Equidae still living today, and they’ve remained relatively unchanged since they first evolved around 50 million years ago.
 
Like their closest relatives, tapirs are vegetarians. Their prehensile noses, also called proboscises, help them reach and grasp hanging fruit. Tapirs spend much of their time swimming and feasting on aquatic plants. Their proboscises even allow them to snorkel in deep waters. Of course, tapirs must be wary of aquatic predators like alligators, and crocodiles, as well as animals like jaguars that spend much of their time by the waterside. By far the biggest threats faced by tapirs, though, are habitat destruction and poaching. All tapir species are endangered, which is bad news not only for them but for their habitats. Tapirs play a vital role in their ecosystems as seed-spreaders. Their droppings not only disperse seeds from all the various fruits they eat, they also provide nutrients for the seeds, improving the chances that new fruit trees will grow. Such trees feed other animal species with their fruit and help decrease soil erosion. The world just can’t afford to let these horse ancestors gallop off into the sunset.

 
[Image description: A brown-colored South American tapir at in a zoo enclosure with grass, mud, and rocks. The copyright holder of this work has released it into the public domain. This applies worldwide.] Credit & copyright: LadyofHats, Wikimedia Commons.

Who knew that you can use the same stuff to clean dirt and water? Scientists at University of Waterloo have found a way to remove a harmful form of chromium from the environment using a form of charcoal called biochar. Biochar is a popular soil amendment made by burning organic waste in a low oxygen environment. Like regular charcoal, biochar’s particular properties can vary depending on what types of plants are used to make it, but no matter what, it’s a carbon-rich substance that can improve soil health. One of the ways it does this is by absorbing toxic pollutants in the soil, but the recent discovery of its effects on chromium has researchers particularly excited.
 
Chromium is the element that makes stainless steel stainless. The heavy metal exists in two very different forms. One is chromium(III), which is not only harmless, but essential to the proper function of the human body as a micronutrient. Chromium(VI), on the other hand, is a dangerous carcinogen created during industrial processes like leather tanning and the creation of stainless steel. Symptoms of chromium(VI) can be as mild as skin rashes or upset stomachs, but it can also lead to stomach ulcers, respiratory problems, reproductive issues, damage to the kidneys or liver, and ovarian cancer. Chromium(VI) can be difficult to remove from groundwater, but that’s where biochar comes in. Researchers found that when biochar was added to contaminated water, it was highly effective at absorbing chromium(VI). In fact, biochar actually converted the toxic chromium(VI) to the non-toxic chromium(III). Apparently, in the presence of biochar, the chromium isotopes fractionated, with lighter isotopes being removed faster than heavier ones. Looking at this ratio of different isotopes also makes it much easier for researchers to monitor the progress of groundwater cleanup. It’s a dirty job, but biochar can do it.

 
[Image description: A pile of biochar on a white tarp.] Credit & copyright: USDA Forest Service photo by Deborah Page-Dumroese. Public Domain.