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Do Sharks Really Not Get Cancer?

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"Take shark cartilage," the doctor on the daytime talk show says. "Sharks don’t get cancer, and the pills will keep you from getting it, too." The thinking behind these pills is that shark cartilage has demonstrated anti-angiogenic properties—that is, it slows or stops the development of blood vessels. Since tumors need networks of blood vessels to survive and grow, cutting off vessel growth should starve, shrink and destroy a tumor. It seems to work for the sharks, argued best-sellers like Sharks Don’t Get Cancer: How Shark Cartilage Could Save Your Life and Sharks Still Don’t Get Cancer.

There’s two big problems here, though. The first is that, while some anti-angiogenesis therapies and medications are effective and have been approved by the FDA for treating cancers, cartilage pills aren’t one of them. The pills don’t make good on the claims made about them. Cartilage pill makers and pushers base their promotions around a very small body of research that shows, says the American Cancer Society, only a “modest ability to slow the growth of new blood vessels in laboratory cell cultures and in animals” and, in a series of trials that have been critiqued for poor controls and methodology, mixed results in humans. Another study suggested that a group of patients with advanced cancer went into remission thanks to cartilage treatment, but the results weren’t published in a peer-reviewed journal and the National Cancer Institute later called the study "incomplete and unimpressive.” 

The overwhelming majority of peer-reviewed and published evidence goes against shark cartilage’s supposed anti-cancer abilities. In numerous trials with both human patients and mouse models, researchers have concluded that shark cartilage provides no benefit against cancers. Both the FDA and FTC have pulled shark cartilage products from the market and/or fined their manufacturers for making unproven claims about anti-cancer properties.

The second problem is that the very foundation of the cartilage pill cure—the idea that sharks don’t get cancer—isn’t at all true.

Sharks get cancer. We knew that even before people started claiming that they didn’t and using that to market cartilage pills. The first tumor recorded on a cartilaginous fish was found on a skate in 1853, and the first found on a shark followed in 1908. Since then, researchers have found some 40 instances of cancerous tumors in at least 24 shark species. These tumors were found in various parts of the body—including in the cartilage and on the face of this poor great white shark.

Image courtesy of Andrew Fox and Sam Cahir 

So, yes, Virginia, there are cancer-stricken sharks, and using bits and pieces of them in pills won’t do anything for you. 

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Sylke Rohrlach, Wikimedia Commons // CC BY-SA 4.0
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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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