There are some 70,000 species of crustacean—the group that includes crabs, lobsters, shrimp and crayfish—in the world, and until very recently, none of them were known to be venomous. This has made them the odd animals out in their phylum, Arthropoda, which contains tens of thousands of venomous species across its other three subphylums.
Now, biologists have found an exception to the trend. Meet the remipede Speleonectes tulumensis. These tiny critters look like white centipedes, with long segmented bodies and scores of swimming legs, and call the underground caves of Mexico and Central America home. They were first scientifically described in the early 1980s, but studied little because the cave networks they swim through are difficult to navigate and often dangerous to work in. One group of researchers that kept at it, though, discovered that the remipedes, while blind, are formidable predators and feed on the shrimp that share their underground pools.
On closer examination, biologists from the Natural History Museum in London discovered that the remipedes had a needle-like fang on either side of their head, each attached to a reservoir surrounded by muscle that could pump fluid out through the needle point. Deep inside the crustacean’s body, they also found a gland that produces venom for storage in the reservoirs.
Remipede venom is odd compared to that of other arthropods. While some spiders, for example, use venom consisting of tiny neurotoxic proteins, the remipede’s toxic cocktail is dominated by larger enzymes that break down the exoskeletons of their prey and destroy proteins in their bodies, softening their defenses and making their insides more easily digestible. In its makeup, the researchers say, remipede’s venom is more like that of vipers than any of its arthropod cousins. There is one familial similarity, though: a neurotoxin that paralyzes the remipede’s victims and is nearly identical to one found in spiders.
With so many crustaceans out there, why is the remipede the only one to become venomous? The researchers think that because the group has such varied diets—some are filter feeders, some are scavengers—none of them really needed a potent weapon for taking down large prey. While remipedes have also been seen filtering small bits of food from the water, their environment and lifestyle pressured them into going toxic.
Stakeouts, sonar studies, and a 24-hour video feed have all been set up in an effort to confirm the existence of the legendary Loch Ness Monster. Now, the Associated Press reports that an international team of scientists will use DNA analysis to learn what's really hiding in the depths of Scotland's most mysterious landmark.
The team, led by Neil Gemmell, who researches evolutionary genetics at the University of Otago in New Zealand, will collect 300 water samples from various locations and depths around the lake. The waters are filled with microscopic DNA fragments animals leave behind as they swim, mate, eat, poop, and die in the waters, and if Nessie is a resident, she's sure to leave bits of herself floating around as well.
After extracting the DNA from the organic material found in the water samples, the scientists plan to sequence it. The results will then be compared to the DNA profiles of known species. If there's evidence of an animal that's not normally found in the lake, or an entirely new species, the researchers will hopefully spot it.
Gemmell is a Nessie skeptic, and he says the point of the project isn't necessarily to discover new species. Rather, he wants to create a genetic profile of the lake while generating some buzz around the science behind it.
If the study goes according to plan, the database of Loch Ness's inhabitants should be complete by 2019. And though the results likely won't include a long-extinct plesiosaur, they may offer insights about other invasive species that now call the lake home.
Here in the Americas, lake monster legends are a dime a dozen. More than a few of them were probably inspired by these ancient-looking creatures. In honor of World Turtle Day, here are 10 things you might not have known about snapping turtles.
1. THE COMMON SNAPPING TURTLE IS NEW YORK'S OFFICIAL STATE REPTILE.
Elementary school students voted to appoint Chelydra serpentina in a 2006 statewide election. Weighing as much as 75 pounds in the wild (and 86 in captivity), this hefty omnivore’s natural range stretches from Saskatchewan to Florida.
2. ALLIGATOR SNAPPING TURTLES CAN BE LARGE. (VERY LARGE.)
Utterly dwarfing their more abundant cousin, alligator snappers (genus: Macrochelys) are the western hemisphere’s biggest freshwater turtles. The largest one on record, a longtime occupant of Chicago’s Shedd Aquarium, weighed 249 pounds.
A monstrous 403-pounder was reported in Kansas during the Great Depression, though this claim was never confirmed.
3. COMMON SNAPPERS HAVE LONGER NECKS AND SPIKIER TAILS.
Alligator snappers also display proportionately bigger heads and noses plus a trio of tall ridges atop their shells. Geographically, alligator snapping turtles are somewhat restricted compared to their common relatives, and are limited mainly to the southeast and Great Plains.
4. BOTH VARIETIES AVOID CONTACT WITH PEOPLE.
If given the choice between fight and flight, snapping turtles almost always distance themselves from humans. The animals spend the bulk of their lives underwater, steering clear of nearby Homo sapiens. However, problems can arise on dry land, where the reptiles are especially vulnerable. Females haul themselves ashore during nesting season (late spring to early summer). In these delicate months, people tend to prod and handle them, making bites inevitable.
5. YOU REALLY DON'T WANT TO GET BITTEN BY ONE.
Snapping turtle jaw strength—while nothing to sneeze at—is somewhat overrated. Common snapping turtles can clamp down with up to 656.81 newtons (N) of force, though typical bites register an average of 209 N. Their alligator-like cousins usually exert 158 N. You, on the other hand, can apply 1300 N between your second molars.
Still, power isn’t everything, and neither type of snapper could latch onto something with the crushing force of a crocodile’s mighty jaws. Yet their sharp beaks are well-designed for major-league shearing. An alligator snapping turtle’s beak is capable of slicing fingers clean off and (as the above video proves) obliterating pineapples.
Not impressed yet? Consider the following. It’s often said that an adult Macrochelys can bite a wooden broom handle in half. Intrigued by this claim, biologist Peter Pritchard decided to play MythBuster. In 1989, he prodded a 165-pound individual with a brand new broomstick. Chomp number one went deep, but didn’t quite break through the wood. The second bite, though, finished the job.
6. SCIENTISTS RECENTLY DISCOVERED THAT THERE ARE THREE SPECIES OF ALLIGATOR SNAPPING TURTLES.
A 2014 study trisected the Macrochelys genus. For over a century, naturalists thought that there was just a single species, Macrochelys temminckii. Closer analysis proved otherwise, as strong physical and genetic differences exist between various populations. The newly-christened M. suwanniensis and M. apalachicolae are named after their respective homes—namely, the Suwannee and Apalachicola rivers. Further west, good old M. temminckii swims through the Mobile and the Mississippi.
7. THANKS TO A 19TH CENTURY POLITICAL CARTOON, COMMON SNAPPING TURTLES ARE ALSO KNOWN AS "OGRABMES."
Drawn by Alexander Anderson, this piece skewers Thomas Jefferson’s signing of the unpopular Embargo Act. At the president’s command, we see a snapping turtle bite some poor merchant’s hind end. Agitated, the victim calls his attacker “ograbme”—“embargo” spelled backwards.
8. ALLIGATOR SNAPPERS ATTRACT FISH WITH AN ORAL LURE …
You can’t beat live bait. Anchored to the Macrochelys tongue is a pinkish, worm-like appendage that fish find irresistible. Preferring to let food come to them, alligator snappers open their mouths and lie in wait at the bottoms of rivers and lakes. Cue the lure. When this protrusion wriggles, hungry fish swim right into the gaping maw and themselves become meals.
Alligator snappers are anything but picky. Between fishy meals, aquatic plants also factor into their diet, as do frogs, snakes, snails, crayfish, and even relatively large mammals like raccoons and armadillos. Other shelled reptiles are fair game, too: In one Louisiana study, 79.82% of surveyed alligator snappers had turtle remains in their stomachs.
10. YOU SHOULD NEVER PICK A SNAPPER UP BY THE TAIL.
Ideally, you should leave the handling of these guys to trained professionals. But what if you see a big one crossing a busy road and feel like helping it out? Before doing anything else, take a few moments to identify the turtle. If it’s an alligator snapper, you’ll want to grasp the lip of the upper shell (or “carapace”) in two places: right behind the head and right above the tail.
Common snappers demand a bit more finesse (we wouldn’t want one to reach back and nip you with that long, serpentine neck). Slide both hands under the hind end of the shell, letting your turtle’s tail dangle between them. Afterwards, clamp down on the carapace with both thumbs.
Please note that lifting any turtle by the tail can permanently dislocate its vertebrae. Additionally, remember to move the reptile in the same direction that it’s already facing. Otherwise, your rescue will probably turn right back around and try to cross the road again later.