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Why Don't You See Great White Sharks in Aquariums?

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The great white shark is one of the most iconic creatures in the animal kingdom. Its fearsome reputation has earned it starring roles in books, blockbuster movies, and countless TV documentaries. But while they’re ubiquitous in pop culture, there’s one place where you won’t find these apex predators, and that’s behind the glass walls of an aquarium.

Many aquariums are home to sharks, including species like nurse sharks and sand tiger sharks. But the most famous member of the group, the great white, is almost always missing from the lineup—which isn’t for a lack of trying. As Vox illustrates in the video below, aquariums have a long and unsuccessful history of trying to keep great white sharks in captivity.

Institutions like SeaWorld and San Francisco's Steinhart Aquarium housed great whites in the '70s, '80s, and '90s—the decades following Jaws mania. But each attempt was met with the same problems: The sharks had trouble eating and swimming, and just generally acted unwell from the moment they arrived. A white shark that lasted more than a week in an aquarium was an anomaly.

While many fish, including sharks, easily adapt to life inside a tank, those same walls often turn out to be fatal for great whites. That’s because the species has evolved to travel fast and for great distances through the open ocean. When kept inside enclosures, the sharks tend to ram into walls and injure themselves. Sometimes they stop swimming altogether, and for an organism that needs water constantly flowing over its gills to breathe, that can lead to a quick death. Experts also suspect that being surrounded by glass might either confuse or overload the shark's electroreception system, which is used to sense the electrical signals given off by fish in the open ocean, not necessarily inside a glass box.

In 2004 the Monterey Bay Aquarium proved that with a large-enough tank and intensive support, a great white could survive in captivity for an extended amount of time. But even the system they developed worked only for smaller baby sharks, and even then it didn’t stop every specimen from bumping into the glass. (The shark that fared the best was released after 198 days, not due to her own health issues but because she had attacked two other sharks.)

Monterey Bay stopped hosting the sharks in 2011, but aquariums around the world are still attempting to support great whites without taking the same level of precaution. Last year, an aquarium in Japan announced the acquisition of a 11.5-foot male, the first adult great white ever held in captivity, only for it to die three days later. No matter how awesome they may be to view in person, fans should probably stick to watching great whites during Shark Week.

[h/t Vox]

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Animals
Scientists Discover 'Octlantis,' a Bustling Octopus City
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Sylke Rohrlach, Wikimedia Commons // CC BY-SA 4.0

Octopuses are insanely talented: They’ve been observed building forts, playing games, and even walking on dry land. But one area where the cephalopods come up short is in the social department. At least that’s what marine biologists used to believe. Now a newly discovered underwater community, dubbed Octlantis, is prompting scientists to call their characterization of octopuses as loners into question.

As Quartz reports, the so-called octopus city is located in Jervis Bay off Australia’s east coast. The patch of seafloor is populated by as many as 15 gloomy octopuses, a.k.a. common Sydney octopuses (octopus tetricus). Previous observations of the creatures led scientists to think they were strictly solitary, not counting their yearly mating rituals. But in Octlantis, octopuses communicate by changing colors, evict each other from dens, and live side by side. In addition to interacting with their neighbors, the gloomy octopuses have helped build the infrastructure of the city itself. On top of the rock formation they call home, they’ve stored mounds of clam and scallop shells and shaped them into shelters.

There is one other known gloomy octopus community similar to this one, and it may help scientists understand how and why they form. The original site, called Octopolis, was discovered in the same bay in 2009. Unlike Octlantis, Octopolis was centered around a manmade object that had sunk to the seabed and provided dens for up to 16 octopuses at a time. The researchers studying it had assumed it was a freak occurrence. But this new city, built around a natural habitat, shows that gloomy octopuses in the area may be evolving to be more social.

If that's the case, it's unclear why such octo-cities are so uncommon. "Relative to the more typical solitary life, the costs and benefits of living in aggregations and investing in interactions remain to be documented," the researchers who discovered the group wrote in a paper published in Marine and Freshwater Behavior and Physiology [PDF].

It’s also possible that for the first time in history humans have the resources to see octopus villages that perhaps have always been bustling beneath the sea surface.

[h/t Quartz]

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This Just In
Criminal Gangs Are Smuggling Illegal Rhino Horns as Jewelry
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Valuable jewelry isn't always made from precious metals or gems. Wildlife smugglers in Africa are increasingly evading the law by disguising illegally harvested rhinoceros horns as wearable baubles and trinkets, according to a new study conducted by wildlife trade monitoring network TRAFFIC.

As BBC News reports, TRAFFIC analyzed 456 wildlife seizure records—recorded between 2010 and June 2017—to trace illegal rhino horn trade routes and identify smuggling methods. In a report, the organization noted that criminals have disguised rhino horns in the past using all kinds of creative methods, including covering the parts with aluminum foil, coating them in wax, or smearing them with toothpaste or shampoo to mask the scent of decay. But as recent seizures in South Africa suggest, Chinese trafficking networks within the nation are now concealing the coveted product by shaping horns into beads, disks, bangles, necklaces, and other objects, like bowls and cups. The protrusions are also ground into powder and stored in bags along with horn bits and shavings.

"It's very worrying," Julian Rademeyer, a project leader with TRAFFIC, told BBC News. "Because if someone's walking through the airport wearing a necklace made of rhino horn, who is going to stop them? Police are looking for a piece of horn and whole horns."

Rhino horn is a hot commodity in Asia. The keratin parts have traditionally been ground up and used to make medicines for illnesses like rheumatism or cancer, although there's no scientific evidence that these treatments work. And in recent years, horn objects have become status symbols among wealthy men in countries like Vietnam.

"A large number of people prefer the powder, but there are those who use it for lucky charms,” Melville Saayman, a professor at South Africa's North-West University who studies the rhino horn trade, told ABC News. “So they would like a piece of the horn."

According to TRAFFIC, at least 1249 rhino horns—together weighing more than five tons—were seized globally between 2010 and June 2017. The majority of these rhino horn shipments originated in southern Africa, with the greatest demand coming from Vietnam and China. The product is mostly smuggled by air, but routes change and shift depending on border controls and law enforcement resources.

Conservationists warn that this booming illegal trade has led to a precipitous decline in Africa's rhinoceros population: At least 7100 of the nation's rhinos have been killed over the past decade, according to one estimate, and only around 25,000 remain today. Meanwhile, Save the Rhino International, a UK-based conservation charity, told BBC News that if current poaching trends continue, rhinos could go extinct in the wild within the next 10 years.

[h/t BBC News]

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