JUN 16, 2019 7:56 AM PDT

These Fish Eggs Hatch Even After Passing Through a Swan's Digestive Tract

WRITTEN BY: Anthony Bouchard

Scientists have long been captivated by killifish because they tend to pop up in unexplained places with seemingly no apparent sign of origin. While they typically appear in the fresh and brackish bodies of water across the Americas, some also appear in ephemeral waters, such as accumulations of floodwater, seasonal ponds, and secluded desert pools.

A killifish egg.

Image Credit: Lecea-Unisinos

The mystery regarding how killifish end up in such peculiar places has left experts scratching their heads for ages, but new research published just this month in the journal Ecology may finally provide some much-needed insight into how this happens.

Students at Brazil’s Unisinos University were purportedly in the midst of investigating flowering plants that managed to grow despite sprouting in bird-based fecal matter. To their interest, a fecal sample from a coscoroba swan contained an intact killifish egg, and the young scientists were particularly curious to know if such an egg would hatch under the same circumstances that the plant seeds managed to grow.

Related: Bird beak shapes aren't influenced by feeding behavior, study confirms

In an effort to answer this question, the students took to a local zoo where they could mix hundreds of killifish eggs into the captive swan feed and collect more fecal samples. Once all the killifish eggs passed through the birds’ digestive systems, an astonishingly low number of those made it through unscathed; of those that survived, one managed to hatch almost 49 days after being defecated.

The results confirm that killifish eggs can indeed hatch even after being ingested by waterfowl, and as you might come to expect, this could explain why killifish sometimes find themselves in such odd places. Swans don’t stay put after eating a meal, and upon ingesting the killifish eggs, the birds disperse them everywhere they visit via defecation.

As for what makes this possible, killifish eggs are biologically-tailored to surviving periods of partial dehydration, and this makes them somewhat resilient to peculiar circumstances such as what’s being described here. Moreover, swans’ digestive systems aren’t as robust as those found in other animals, and this is another factor that aids in the killifish egg’s survival.

Related: Walleye fish populations appear to be declining

While it seems at first glance like the mystery regarding how killifish make their way to such strange places has been solved, there’s likely more to the story than swan poop alone. With a. little luck, future research could shed more light on this process.

Source: New York Times, Ecology

About the Author
  • Fascinated by scientific discoveries and media, Anthony found his way here at LabRoots, where he would be able to dabble in the two. Anthony is a technology junkie that has vast experience in computer systems and automobile mechanics, as opposite as those sound.
You May Also Like
SEP 09, 2021
Chemistry & Physics
"Shape-Shifting" Birds: Climate Change's Newest Outcome
SEP 09, 2021
"Shape-Shifting" Birds: Climate Change's Newest Outcome
A new study released last Tuesday highlights a surprising response to climate change: physical changes in animal mo ...
OCT 02, 2021
Genetics & Genomics
After Mass Extinction, All Modern Snakes Evolved From Only a Few Survivors
OCT 02, 2021
After Mass Extinction, All Modern Snakes Evolved From Only a Few Survivors
Reporting in Nature Communications, scientists have suggested that every living snake on earth evolved from just a handf ...
OCT 08, 2021
Cannabis Sciences
Research on Cannabis Patches and Topical Lotions to Manage Symptoms of Parkinson's Disease
OCT 08, 2021
Research on Cannabis Patches and Topical Lotions to Manage Symptoms of Parkinson's Disease
As medical cannabis becomes legalized around the globe, patients need to explore which routes of cannabis delivery best ...
OCT 14, 2021
Microbiology
Leprosy Has Been Detected in Wild Chimpanzees for the First Time
OCT 14, 2021
Leprosy Has Been Detected in Wild Chimpanzees for the First Time
Leprosy has been infecting people since ancient times, and is estimated to have caused about 202,000 new infections in 2 ...
OCT 20, 2021
Earth & The Environment
Building Better Crops: Pumpkin and Squash
OCT 20, 2021
Building Better Crops: Pumpkin and Squash
It’s the time of year for all things pumpkin. But what do you really know about pumpkins? They are generally consi ...
OCT 20, 2021
Microbiology
Bacteria From Cats Could Help Treat Infections
OCT 20, 2021
Bacteria From Cats Could Help Treat Infections
Many animals, including humans and cats, harbor huge colonies of microbes, which may live in places like the skin, or th ...
Loading Comments...