Some Fish Eggs Can Hatch After Being Pooped Out by Swans

iStock/olaser
iStock/olaser

A question that’s often baffled scientists is how certain species of fish can sometimes appear—and even proliferate—in isolated bodies of water not previously known to harbor them. A new study has demonstrated that the most unlikely explanation might actually be correct: It’s possible they fell from the sky.

Specifically, from the rear end of a swan.

A study in the journal Ecology by researchers at the Unisinos University in Brazil found that killifish eggs can, in rare cases, survive being swallowed by swans, enduring a journey through their digestive tracts before being excreted out. This kind of fecal public transportation system explains how killifish can pop up in ponds, flood waters, and other water bodies that would seem an unlikely place for species to suddenly appear.

After discovering that some plants could survive being ingested and then flourish in swan poop, researchers took notice of a killifish egg present in a frozen fecal sample. They set about mixing two species of killifish eggs into the food supply of coscoroba swans living in a zoo. After waiting a day, they collected the poop and dug in looking for the eggs.

Of the 650 eggs they estimated to have been ingested by the swans, about five were left intact. Of those, three continued to develop. Two died of a fungal infection, but one survived, enduring 30 hours in the gut and hatching 49 days after being excreted.

Because killifish eggs have a thick outer membrane, or chorion, they stand a chance of coming through the digestive tract of an animal intact. Not all of what a swan ingests will be absorbed; their stomachs are built to extract nutrients quickly and get rid of the whatever's left so the birds can eat again. In rare cases, that can mean an egg that can go on to prosper.

Not all fish eggs are so durable, and not all fish are quite like the killifish. Dubbed the "most extreme" fish on Earth by the BBC, killifish have adapted to popping up in strange environments where water may eventually dry up. They typically live for a year and deposit eggs that can survive in soil, delaying their development until conditions—say, not being inside a swan—are optimal. One species, the mangrove killifish, can even breathe through its skin. When water recedes, they can survive on land for over two months, waddling on their bellies or using their tails to "jump" and eat insects. A fish that can survive on dry land probably doesn't sweat having to live in poop.

The researchers plan to study carp eggs next to see if they, too, can go through a lot of crap to get to where they’re going.

[h/t The New York Times]

A Stranger Things Fan Is Selling Epic Demogorgon Dog Costumes on Etsy

Joe Keery, Maya Hawke, Priah Ferguson, and Gaten Matarazzo in Stranger Things.
Joe Keery, Maya Hawke, Priah Ferguson, and Gaten Matarazzo in Stranger Things.
Netflix

Stranger Things is great at placing the truly terrifying alongside the absolutely adorable. One minute we are gushing over Eleven and Mike’s teen romance, and the next we’re jumping off the couch at the sight of those possessed by the Mind Flayer.

No matter how seamless the Duffer Brothers' Netflix series is in weaving together these moments, it seems like it would be impossible to make the Demogorgon cute. But somehow, one crafty fan has done just that.

Etsy shop ThatCraftyFriendShop has created Demogorgon headpieces that fit perfectly on your dog’s head.

People reports that the headpieces range in size from extra small (for 5- to 10-pound dogs) all the way to extra large (for dogs over 75 pounds). Prices range from $25 to $75, depending on the size of your four-legged friend.

These wool and felt doggy costumes are perfect for Halloween, or even a Stranger Things watch party while you continue to binge and re-binge the third seasonwith a decked-out doggy by your side.

[h/t People]

Georgia Beachgoers Saved a Pod of Pilot Whales That Washed Ashore

Jeff J Mitchell/Getty Images
Jeff J Mitchell/Getty Images

A day at the shore quickly turned into a rescue situation for beachgoers on St. Simons Island, Georgia this week when a pod of pilot whales washed ashore. Beaching can be disastrous for whales, but thanks to a group of first responders and volunteers, most of the stranded marine mammals were returned to safety, USA Today reports.

Spotting whales off the coast of Georgia isn't unusual, but what occurred at St. Simons Island the afternoon of Tuesday, July 16 was out of the ordinary. The pilot whales had swum so close to the shore that they had become stuck on the sand—and there were dozens of them. The animals could have died from dehydration at low tide or possibly drowned if the tide covered their blowholes.

Fortunately, the beachgoers watching the situation unfold acted fast. They waded into the sea and manually pushed the small whales back into deeper waters where they could swim freely. First responders from the Georgia Department of Natural Resources (DNR) also aided in the rescue effort.

The heroic volunteers weren't able to save every whale. Two of the mammals became incapacitated and had to be euthanized. But according to the Glynn County Emergency Management and Homeland Security Agency, the majority of the whales swam away unharmed. "This has been an unusual occurrence, but events like these can really show the level of care and support from our community," the agency wrote on its Facebook page. "Thank you to everyone that helped those that couldn’t help themselves today."

Beaching is a rare event that still isn't fully understood by scientists. In the case of these pilot whales, which travel in pods, one sick whale may have swum too close to land and led the rest of the whales to danger. The DNR plans to conduct autopsies on the two whales who perished.

[h/t USA Today]

SECTIONS

arrow
LIVE SMARTER