15 Examples of the Most Epic Metamorphoses from Youth to Adult

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We’re all familiar with the most dramatic metamorphosizers of the animal kingdom: butterflies. They go from a tiny egg to an awkward wiggling caterpillar to mysterious pupa to a delicate, colorful winged creature. However, there are many other animals besides butterflies that undergo dramatic transformations from youth to adult. Here are 15 of the most epic metamorphoses seen in nature.

1. LADYBUGS (COCCINELLIDAE)

What’s black, white, and red all over? Many ladybugs are—but only in their final stage of life. Turns out these little beetles undergo one of the most epic metamorphoses in the animal kingdom: For most species, after adult female ladybugs mate, they lay a clutch of tiny yellow eggs right in the middle of an aphid colony, usually on the underside of a leaf. Eggs hatch in a week, revealing spiky black worm-like larvae that readily gobble up the aphids around them. When a larva is fully grown, it changes into a blob-like yellow pupa. Finally, the black, white and red (or sometimes yellow or orange) insect appears.

2. MAYFLY (EPHEMEROPTERA)

Mayflies, the less-elegant cousins of dragonflies and damselflies, have one of the most unique metamorphoses of all insects. Most insects’ life stages move from egg to nymph to pupa to adult, but mayflies do not have a pupa stage. Instead, it is the only type of insect to undergo a subimago stage, meaning it’s almost an adult in the sense it grows wings … but cannot fly long distances and isn’t yet sexually mature. The mayfly’s final life stage, the fully flighted and sexually mature imago or adult, is extremely short, lasting just a few hours to a few days.

3. PEACOCK SPIDER (MARATUS)

Left: Jurgen Otto, Flickr // CC BY-NC-ND 2.0; Right: Jurgen Otto, Flickr // CC BY-NC-ND 2.0

Peacock spiders are tiny, venomous, and beautiful (especially the colorfully rumped males) arthopods native to Australia. Male peacock spiders are so beautiful, in fact, it’s hard to believe that, like all spiders, they go through some not-so-glamorous life stages: egg, egg sac, spiderling, adult. When male peacock spiders reach sexual maturity they try to seduce less-colorful female peacock spiders by performing a showy dance.

4. NUDIBRANCH (NUDIBRANCHIA)

While adult nudibranchs are essentially colorful and ornate blobs of the sea, they don’t start out that way. In fact, after hatching, nudibranch larvae are tiny, plain-looking and have small snail-like shells. Over the course of two months they morph from this plain stage into adults, along the way getting larger and more colorful, losing their shells, and growing gills and feelers, called rhinophores.

5. CROWN OF THORNS STARFISH (ACANTHASTER PLANCI)

Another sea creature that looks completely different as an adult than a juvenile is the crown of thorns starfish. When looking at an adult, it’s easy to see where this creature gets its name: It’s completely covered with dangerous-looking sharp spikes. But after hatching, it looks like not much more than a translucent, floating blob. Over time it grows arms, and later, spikes, then fixes itself to rocks where it feeds on coral.

6. IMMORTAL JELLYFISH (TURRITOPSIS DOHRNII)

The secret to a long and prosperous life, it turns out, is to be a jellyfish. The aptly named immortal jellyfish begins life as an egg, like all other jellies. It then enters the free-swimming larva stage, then settles down into a polyp on the ocean floor, and then finally morphs into a sexually mature jellyfish. Unlike most other jellies, an immortal jellyfish is capable of reverting back into the polyp stage at any time it faces environmental stress, attacks by predators, sickness or old age—essentially being reborn as a young jelly.

7. FLATFISH (PLEURONECTIFORMES)

Think of Pablo Picasso’s most asymmetrically painted human face, stick it onto a fish, and there you have a flatfish. These fish, which include flounder and sole among other species, begin life inside tiny eggs that float up to the surface of the sea. For a few weeks, a larval flatfish swims upright and looks just like a typical baby fish. But after a few weeks its skull bones shift and one eye migrates to the opposite side of its face, forcing the now-lopsided fish to swim sideways. Eventually, when its facial features all move to one side of its face, it changes color and moves to live on the bottom of the sea, its blind side facing down.

8. EASTERN HELLBENDER (CRYPTOBRANCHUS ALLEGANIENSIS)

Left: Pete and Noe Woods, Flickr // CC BY 2.0; Right: Projosh More, Flickr // CC BY 2.0

Also called the snot otter and devil dog, the eastern hellbender is a giant type of salamander not exactly known for being beautiful in its adult form. Slippery, wrinkly and the color of mud, they’re right at home at the bottom of rivers, where they can live up to 50 years. Like all salamanders, hellbenders begin as eggs. From their eggs they hatch, coming into the world small and adorable. As time passes, they grow larger and less cute.

9. CHALAZODES BUBBLE NEST FROG (RAORCHESTES CHALAZODES)

Don’t let this lime-green frog’s bright and cheery looks fool you: It lives in only one tiny area in India and is critically endangered, threatened most by an ever-shrinking habitat. These creatures were once believed to lay eggs that developed into tadpoles on pond surfaces like many other frogs. But in 2014, it was discovered that they had a different reproductive strategy: The frogs crawl into a living bamboo shoot that has a hole in it (probably created by insects or rodents) and lay their eggs there. The creatures skip the tadpole stage entirely, hatching as froglets. Because they don't have a tadpole stage, the species doesn't require water to lay its eggs.

10. MIMIC POISON DART FROG (RANITOMEYA IMITATOR)

Mattias Starkenberg, Wikimedia Commons // CC BY-SA 3.0

Covered in bright hues spotted, striped, banded, and blotched with contrasting black, the poison dart frog is one of the most striking-looking of all amphibians. Yet they don’t start out that way. After hatching, young mimic poison dart frogs are looked after by their mother, who lays a clutch of unfertilized feeder eggs to provide them with some nourishment (and, at least for some species of poison dart frog, toxicity). Tadpoles are brown and black, growing more colorful with age until they reach their fantastic adult form.

11. KEA (NESTOR NOTABILIS)

The kea is a large, vulnerable species of parrot native to New Zealand, with green and blue feathers on its back and brown and orange feathers on its underside. While adult keas appear majestic and beautiful, they don’t start out that way. Baby keas retain an alien-like, sparse white hairdo for several months after hatching. Keas are considered a very intelligent species, observed working together and using tools.

12. LAYSAN ALBATROSS (PHOEBASTRIA IMMUTABILIS)

Laysan albatrosses are another species of bird where the babies are very little like their parents. But unlike baby keas, baby Laysan albatrosses hatch as adorable fuzzy gray blobs. As they grow older, the babies slowly grow adult feathers and lose their baby feathers. This leaves them with unique hairdos that sometimes make them look like human celebrities. Ringo Starr, anyone?

13. FLAMINGO (PHOENICOPTERUS)

Left: Getty Images // Right: iStock

Unlike keas and albatrosses, baby flamingoes look a lot like their parents, except they’re missing something: color. Flamingo chicks hatch with gray and/or white feathers, over time taking on the same pink hue as their parents, which becomes more intense over time. Why? Well, you are what you eat, and flamingoes eat shrimp and algae rich in carotenoids, the same pigments that cause shrimp to turn pink when cooked.

14. VIRGINIA OPOSSUM (DIDELPHIS VIRGINIANA)

Virginia opossums are scavengers, eating carrion and rotting vegetation, and that helps keep the environment clean. Virginia opossums are native to North America, where they’re the continent’s only living marsupials. These opossums have pouches for carrying their babies, just like kangaroos. Also like kangaroos they give birth to large numbers of navy-bean-size babies, which grow inside their pouches. When they’re born, they look more like pink jellybeans than animals. Over the course of three to five months, they mature, growing fur, sharp teeth and long tails.

15. GIANT PANDA (AILUROPODA MELANOLEUCA)

Getty Images

Giant pandas are called giant pandas for a reason: They’re enormous in size, weighing up to 250 pounds. But these bamboo-munching bears don’t start out that way. When born, giant panda cubs weigh just 90 to 130 grams (about as much as a small apple). Besides being way smaller in size, baby pandas are also quite sparsely furred—and so they look very different than what they will as fuzzy black-and-white adults.

Why Do Bats Hang Upside Down?

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iStock.com/CraigRJD

Stefan Pociask:

The age-old question of upside down bats. Yes, it is awfully weird that there is an animal—a mammal even—that hangs upside down. Sure, some monkeys do it when they're just monkeying around. And a few other tree climbers, like margays, hang upside down if they are reaching for something or—again, like the margay cat—may actually even hunt that way ... But bats are the only animals that actually spend most of their time hanging upside down: feeding this way, raising their young this way, and, yes, sleeping or roosting this way.

There is actually a very good and sensible reason why they do this: They have to hang upside down so that they can fly.

First off, we have to acknowledge that bats are not birds, nor are they insects. These are the other two animals that have true powered flight (as opposed to gliding). The difference between bat flight and bird or insect flight is weight—specifically, the ratio of weight to lift-capacity of the wings. If you walk up to a bird or insect, most species will be able to fly right up into the air from a motionless position, and do it quickly.

Bats, on the other hand (or, other wing), can’t do that. They have a lot of difficulty taking off from the ground (not that they can’t do it ... it’s just more difficult). Insects and birds often actually jump into the air to give them a start in the right direction, then their powerful wings take them up, up, and away.

Birds have hollow bones; bats don’t. Insects are made of lightweight chitin or soft, light tissue; bats aren’t. And bats don’t have what you could call "powerful" wings. These amazing creatures are mammals, after all. The only flying mammals. Nature found a way to evolve such an unlikely thing as a flying mammal, so some compromises had to be made. Bats, once airborne, manage perfectly well in the air, and can literally fly circles around most birds in flight. The problem is in first getting off the ground.

To compensate for the extra weight that mammals must have, to compensate for the problem of getting off the ground, evolution found another way for bats to transition from being motionless to immediately being able to fly when necessary. Evolution said, “How about if we drop them from above? That way they are immediately in the air, and all they need to do is start flapping."

It was a great idea, as it turns out. Except bat feet aren’t any good for perching on a branch. They are mammals, not birds, so their musculature, their bones, and their tendons are set up in a completely different way. When a bird squats down on a branch, their tendons actually lock their toes into an even tighter grip on the perch. It happens automatically. That’s part of being a bird, and is universal. That’s why they don’t fall off in their sleep.

Bats, as mammals, are set up differently. Therefore, to compensate for that fact, nature said, “How about if we have them hang upside down? That way, their tendons will actually pull their toes closed, just like a bird does from the opposite direction.” So that’s what evolved. Bats hang from the bottom of something, and all they have to do is "let go" and they are instantly flying. In fact, with this gravity-assist method, they can achieve instant flight even faster than birds, who have to work against gravity.

Side note: In case you were wondering how bats poop and pee while upside down ... First off, pooping is no big deal. Bat poop looks like tiny grains of rice; if they are hanging, it just falls to the floor of the bat cave as guano. Pee, however ... well, they have that covered too. They just “hold it” until they are flying.

So there you go. Bats sleep hanging upside down because they are mammals and can’t take off into the air like birds can (at least not without difficulty). But, if they're hanging, all they do is let go.

Makes total sense, right?

Now, having said all that about upside down bats, I must mention the following: Not all of the 1240-plus species of bats do hang upside down. There are exceptions—about six of them, within two different families. One is in South America (Thyropteridae) and the other is in Madagascar (Myzopodidae). The Myzopodidae, which includes just one species, is exceedingly rare.

So it turns out that these bats roost inside the tubes of young, unfurled banana leaves and other similar large leaves. When they attach themselves to the inside of this rolled leaf, they do it head-up. The problem with living inside of rolled-up leaves is that within a few days, these leaves will continue growing, and eventually open up. Whenever that happens, the whole group of bats has to pick up and move to another home. Over and over again. All six of these species of rare bats have a suction cup on each wrist and ankle, and they use these to attach to the smooth surface of the inside of the leaf tube. Evolution: the more you learn, the more amazing it becomes.

This post originally appeared on Quora. Click here to view.

Sorry, But Last Month's Polar Vortex Didn't Wipe Out 95 Percent of Stink Bugs

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iStock.com/drnadig

In the wake of the polar vortex that brought bone-chilling temperatures to the Midwest and Northeast U.S. last month, a silver lining appeared to emerge. Multiple media outlets recently reported that the weather phenomenon may have wiped out as many as 95 percent of brown marmorated stink bugs in areas that weren't accustomed to such frigid conditions.

Unless you like having your home smell like the musky, burnt-cilantro scent of squished stink bugs, we have some bad news: Those reports are not entirely accurate. According to KDKA Radio in Pittsburgh, the Virginia Tech lab experiment that has been widely cited in these articles is a little outdated, having been conducted in 2014.

At the time, it appeared to be a promising find. Researchers from the university had collected stink bugs, placed them in insulated buckets, and waited to see if they'd survive a particularly cold spell. Even though the insects were in a dormant state called diapause, 95 percent of them died when a polar vortex hit the region. That led entomology professor Thomas Kuhar to tell The Washington Post in 2014 that “there should be significant mortality of BMSB (brown marmorated stink bugs) and many other overwinter insects this year."

However, in an email to Mental Floss, Kuhar says the rehashing of "some media misquotes from 2014" led to these too-good-to-be-true reports being recirculated this week. "There is no new research on this topic," he writes. Furthermore, the lab experiment can't easily be applied to real-life scenarios because stink bugs tend to seek shelter during the winter. "Severe sub-freezing temperatures will negatively impact winter survival of these stink bugs if they were unable to find suitable shelter such as inside of houses and sheds," he writes.

These sentiments were echoed by entomologist Chad Gore of Ehrlich Pest Control, who spoke with KDKA Radio. "When they can find that shelter, they can survive the winter. Those that are exposed, they will freeze and we won’t have to worry about them," he said.

But is there still a chance we will see fewer stink bugs in the spring? Gore says don't count on it. "I’d love to be able to reassure everybody and say that 95 percent of all of our stink bugs are going to be gone, but that’s just not going to be the case," he said. "We’re still going to see them."

Even though stink bugs don't bite and are basically harmless (though they sometimes trigger allergic reactions), they can be difficult to trap once they've found a way into one's house. The invasive species is also harmful to crops—especially grapes—and sometimes end up getting pulverized and fermented in red wine. Suffice it to say, a lot of people would be happy if the pests suddenly disappeared. For now, though, we'll have to keep on dreaming.

[h/t KDKA Radio]

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