For the First Time, Scientists Find Jellyfish-Like Animal With ‘Transient’ Anus

SaskiaAcht/iStock.com
SaskiaAcht/iStock.com

Compared to other parts of anatomy, the anus is underappreciated—but without a way to expel waste from the body, all the work that takes places at other stages of digestion wouldn't be good for much. Now scientists may have a better understanding of how the anus evolved after identifying the first "transient" anus in jellyfish, New Scientist reports.

As biologist Sidney L. Tamm reports in the journal Invertebrate Biology, the warty comb jelly (which is really a type of ctenophore, not a cnidarian like true jellyfish) doesn't have a visible anus most of the time. While studying the comb jelly, he discovered it forms one only when it needs to defecate. When waste builds up, the creature's gut or gastrodermis expands until it touches the outer layer known as the epidermis. At this point, the gastrodermis and the epidermis fuse together and form an orifice where there wasn't one before. Waste is disposed of through the newly opened anus, and once the jelly has finished its business, the hole closes up again and the gut and the epidermis go back to being two separate layers.

These two components each consist of a single cell layer, so the anal opening forms quickly. Mature warty comb jellies have to grow a new anus every hour or so, while their larvae do it about once every 10 minutes.

Jellyfish and comb jellies are simple organisms, with one inner tract instead of a more complex system of organs. Some jellies have one opening in their gastrodermis they use for eating, expelling waste, and exchanging reproductive materials. The discovery of the warty comb jelly's transient anus shows how this one-orifice system may have evolved into a tract with a permanent anus millions of years ago.

Comb jellies are some of the oldest animals on Earth, with ancestors appearing as far back as 700 million years ago. Scientists believe they helped set the evolutionary groundwork for systems that are essential to complex life today, such as the nervous system and digestive tract.

[h/t New Scientist]

Aspiring Eagle Scout Is Turning Old Fire Hoses Into Hammocks for Big Cats

iStock.com/tane-mahuta
iStock.com/tane-mahuta

Boy Scouts have to demonstrate skills in multiple areas to graduate to the rank of Eagle Scout. On his quest to reach the top rank in scouting, eighth-grader Payton Crawford is doing something that's unusual for the organization: Knitting hammocks for senior big cats out of old fire hoses, CBS Denver reports.

For his Eagle Scout project, the 11-year-old boy from Colorado wanted to help the Wild Animal Sanctuary in Keenesburg, Colorado. The nonprofit rescues large carnivores from abusive situations and gives them a new home in a 10,000-acre wildlife refuge. There are more than 500 animals living at the site.

When they're not roaming the sanctuary, older big cats like lions, tigers, and leopards will be able to lounge on Crawford's supportive hammocks. He gathered old hoses from fire departments, cut them into the desired lengths, and wove them into hammocks big enough to accommodate a variety of animals. He can make one himself in about two hours, but he needs help carrying the final product.

“It’s just something different that I wanted to try out,” he told CBS. “Give them a better life because they don’t have the luxury we do.”

You can see how Crawford put them together in the video below.

[h/t CBS Denver]

20 Black-and-White Facts About Penguins

iStock/fieldwork
iStock/fieldwork

Who is a penguin's favorite family member? Aunt Arctica! 

We kid! But seven of the 17 species of penguins can be found on the southernmost continent. Here are 20 more fun facts about these adorable tuxedoed birds. 

1. All 17 species of penguins are found exclusively in the Southern Hemisphere.

A group of penguins on an iceberg.
iStock/axily

2. Emperor Penguins are the tallest species, standing nearly 4 feet tall. The smallest is the Little Blue Penguin, which is only about 16 inches.

Three emperor penguins
iStock/Fabiano_Teixeira

3. The fastest species is the Gentoo Penguin, which can reach swimming speeds up to 22 mph.

A gentoo penguin swimming underwater
iStock/chameleonseye

4. A penguin's striking coloring is a matter of camouflage; from above, its black back blends into the murky depths of the ocean. From below, its white belly is hidden against the bright surface.

Penguins swimming in the ocean
iStock/USO

5. Fossils place the earliest penguin relative at some 60 million years ago, meaning an ancestor of the birds we see today survived the mass extinction of the dinosaurs.

Emperor penguins with chicks
iStock/vladsilver

6. Penguins ingest a lot of seawater while hunting for fish, but a special gland behind their eyes—the supraorbital gland—filters out the saltwater from their blood stream. Penguins excrete it through their beaks, or by sneezing.

Penguin swimming in the ocean
iStock/Musat

7. Unlike most birds—which lose and replace a few feathers at a time—penguins molt all at once, spending two or three weeks land-bound as they undergo what is called the catastrophic molt.

Gentoo penguin chick molting
iStock/ChristianWilkinson

8. All but two species of penguins breed in large colonies of up to one thousand birds.

A colony of king penguins
iStock/DurkTalsma

9. It varies by species, but many penguins will mate with the same member of the opposite sex season after season.

Two chinstrap penguins
iStock/Legacy-Images

10. Similarly, most species are also loyal to their exact nesting site, often returning to the same rookery in which they were born.

Magellanic penguin nesting in the ground
iStock/JeremyRichards

11. Some species create nests for their eggs out of pebbles and loose feathers. Emperor Penguins are an exception: They incubate a single egg each breeding season on the top of their feet. Under a loose fold of skin is a featherless area with a concentration of blood vessels that keeps the egg warm.

Penguin eggs
iStock/Buenaventuramariano

12. In some species, it is the male penguin which incubates the eggs while females leave to hunt for weeks at a time. Because of this, pudgy males—with enough fat storage to survive weeks without eating—are most desirable.

A group of emperor penguins and chick
iStock/vladsilver

13. Penguin parents—both male and female—care for their young for several months until the chicks are strong enough to hunt for food on their own.

Penguin chick and parent on a nest
iStock/golnyk

14. If a female Emperor Penguin's baby dies, she will often "kidnap" an unrelated chick.

Three emperor penguin chicks
iStock/AntAntarctic

15. Despite their lack of visible ears, penguins have excellent hearing and rely on distinct calls to identify their mates when returning to the crowded breeding grounds.

Gentoo penguins
iStock/Goddard_Photography

16. The first published account of penguins comes from Antonio Pigafetta, who was aboard Ferdinand Magellan's first circumnavigation of the globe in 1520. They spotted the animals near what was probably Punta Tombo in Argentina. (He called them "strange geese.")

A group of magellanic penguins on the seacoast
iStock/encrier

17. An earlier, anonymous diary entry from Vasco da Gama's 1497 voyage around the Cape of Good Hope makes mention of flightless birds as large as ducks.

A cape penguin in South Africa
iStock/ziggy_mars

18. Because they aren't used to danger from animals on solid ground, wild penguins exhibit no particular fear of human tourists.

Man videotaping a penguin in Antarctica
iStock/Bkamprath

19. Unlike most sea mammals—which rely on blubber to stay warm—penguins survive because their feathers trap a layer of warm air next to the skin that serves as insulation, especially when they start generating muscular heat by swimming around.

Penguin swimming in the ocean
iStock/Musat

20. In the 16th century, the word penguin actually referred to great auks (scientific name: Pinguinus impennis), a now-extinct species that inhabited the seas around eastern Canada. When explorers traveled to the Southern Hemisphere, they saw black and white birds that resembled auks, and called them penguins.

This story was first published in 2017.

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