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Scott Portelli Wildlife Photographer, @scottportelli
Scott Portelli Wildlife Photographer, @scottportelli

Octopuses, Cuttlefish, and Squid Are Thriving in Warming Waters

Scott Portelli Wildlife Photographer, @scottportelli
Scott Portelli Wildlife Photographer, @scottportelli

You’ve heard that dark chocolate can be good for your health, but you’ve probably also heard that just a little piece can be toxic to your dog. What’s good for one species may be deadly for another, and vice versa. A new example: Researchers say that, unlike fish, populations of octopuses, squid, and cuttlefish have actually increased during the last six decades of climate change. The findings were published today in the journal Current Biology.

The cephalopod (literally “head-footed”) family is one of the most remarkable on Earth. Octopuses, cuttlefish, and squid are squishy, strange invertebrates. As such, it was assumed for a long time that they were unintelligent automatons, completely at the mercy of instinct. We now know that nothing could be further from the truth. These astonishing animals have gifts and skills that humans could only dream about.

They also have a triad of traits—short lifespans, flexible development, and rapid growth—that allow them to adapt when other species are going belly-up. Even so, researchers did not expect to find them doing quite this well. In fact, lead author and University of Adelaide biologist Zoë Doubleday was inspired to begin this project by reports of shrinking populations of giant Australian cuttlefish (pictured above).

Doubleday and her colleagues reviewed fishing data on cephalopod catches from 1953 to 2013. Their dataset included information from all over the world about species found in both open water and on sea floors, and included targeted fishing species as well as bycatch. 

Their results suggest that, far from declining in rapidly warming waters, cephalopod populations are actually on the rise. “This is remarkable given the enormous life-history diversity exhibited across these groups,” the authors write, “which were represented in this study by 35 species/genera and six families.”

The uniform increase across species, families, and regions suggests that global trends are at play. Earlier studies had suggested (and the authors of the current study believe) that warming waters might truncate cephalopods’ short life spans even further. And yes, a shorter life span is bad news for an individual, but cramming a lot of generations into a short period of time allows a species to adapt more quickly.

The authors also speculate that, as fish populations shrink, cephalopods may finally be getting some relief from predators and rivals for resources.

But let’s not throw an octopus parade just yet. This study focused on a small subset of cephalopod species, notes Mark Carnall of the Oxford University Museum of Natural History. Additionally, he wrote in an email to mental_floss, “even live cephalopods are hard to identify,” and data collection can vary between and even within countries. On top of that, “many species of cephalopod are only known from a handful of specimens, so data about their diversity is thin on the ground.” And some species, like the highly traded chambered nautilus, are definitely in decline or locally extinct.

Ecosystem dynamics are never simple. An increase in cephalopod populations, if it's happening, could feed, and thus increase, populations of cephalopod predators. Additionally, as fish stocks shrink, humans are turning more to fishing for octopus and squid. And warming waters are not the only product of climate change: Our oceans are also gradually acidifying, which may affect even these resilient “weeds of the sea.”

Editor's Note: This post has been updated to reflect additional insight from an outside expert.

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Animals
Where Do Birds Get Their Songs?
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iStock

Birds display some of the most impressive vocal abilities in the animal kingdom. They can be heard across great distances, mimic human speech, and even sing using distinct dialects and syntax. The most complex songs take some practice to learn, but as TED-Ed explains, the urge to sing is woven into songbirds' DNA.

Like humans, baby birds learn to communicate from their parents. Adult zebra finches will even speak in the equivalent of "baby talk" when teaching chicks their songs. After hearing the same expressions repeated so many times and trying them out firsthand, the offspring are able to use the same songs as adults.

But nurture isn't the only factor driving this behavior. Even when they grow up without any parents teaching them how to vocalize, birds will start singing on their own. These innate songs are less refined than the ones that are taught, but when they're passed down through multiple generations and shaped over time, they start to sound similar to the learned songs sung by other members of their species.

This suggests that the drive to sing as well as the specific structures of the songs themselves have been ingrained in the animals' genetic code by evolution. You can watch the full story from TED-Ed below, then head over here for a sample of the diverse songs produced by birds.

[h/t TED-Ed]

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Animals
Watch the First-Ever Footage of a Baby Dumbo Octopus
NOAA, Wikimedia Commons // Public Domain
NOAA, Wikimedia Commons // Public Domain

Dumbo octopuses are named for the elephant-ear-like fins they use to navigate the deep sea, but until recently, when and how they developed those floppy appendages were a mystery. Now, for the first time, researchers have caught a newborn Dumbo octopus on tape. As reported in the journal Current Biology, they discovered that the creatures are equipped with the fins from the moment they hatch.

Study co-author Tim Shank, a researcher at the Woods Hole Oceanographic Institution in Massachusetts, spotted the octopus in 2005. During a research expedition in the North Atlantic, one of the remotely operated vehicles he was working with collected several coral branches with something strange attached to them. It looked like a bunch of sandy-colored golf balls at first, but then he realized it was an egg sac.

He and his fellow researchers eventually classified the hatchling that emerged as a member of the genus Grimpoteuthis. In other words, it was a Dumbo octopus, though they couldn't determine the exact species. But you wouldn't need a biology degree to spot its resemblance to Disney's famous elephant, as you can see in the video below.

The octopus hatched with a set of functional fins that allowed it to swim around and hunt right away, and an MRI scan revealed fully-developed internal organs and a complex nervous system. As the researchers wrote in their study, Dumbo octopuses enter the world as "competent juveniles" ready to jump straight into adult life.

Grimpoteuthis spends its life in the deep ocean, which makes it difficult to study. Scientists hope the newly-reported findings will make it easier to identify Grimpoteuthis eggs and hatchlings for future research.

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