Missing shark found in South Dakota —

"Rapid City police said an anonymous tip lead them to the 12-foot shark that was found in an open field next to the old Pizza Hut in Box Elder." [Rapid City Journal via Brendan Koerner] — Rob •

Why do shark embryos eat one another? —

Tia Ghose: "[they] cannibalize their littermates in the womb, with the largest embryo eating all but one of its siblings. Now, researchers know why." — Rob •

The shark that only wants a single bite —

The cookiecutter shark is one of those animals that kind of makes you believe nature just likes to mess with us. Instead of killing the things it eats, a cookiecutter shark just takes a bite — leaving a neat, tidy hemispherical divot. As marine biologist Yannis Papastamatiou told reporter Douglas Main, it would be more accurate to call the cookiecutter an "ice cream scoop shark". Despite only being about 20 inches long, the cookiecutter shark will try its luck on a wide variety of prey, including animals much larger than itself. It's been known to bite great white sharks, for instance. And there is one report of a cookiecutter biting a human, although that risk is probably not something you should bother losing sleep over. — Maggie •

10 possibly romantic facts about shark reproduction —

Warning: Story includes photos of a male shark's genitalia. — Maggie •

Editorial note — Cow Week is a tongue-in-cheek look at risk analysis and why we fear the things we fear. It is inspired by the Discovery Channel's Shark Week, the popularity of which is largely driven by the public's fascination with and fear of sharks. Turns out, cows kill more people every year than sharks do. Each day, I will post about a cow-related death, and add to it some information about the bigger picture.

Some cow-related deaths are accidental, or at least understandable. When humans and animals live and work in close proximity, it's not surprising that humans sometimes do things that startle or scare the animals. And when 500-pound animals are scared, bad things can happen.

Other times, though, it really seems like the cows are out to get us. Take this story, related in the July 31st issue of The Times of India. Bhoop Narayan Prajapati, a 65-year-old resident of Deori Township in the Sagar district of Madhya Pradesh, was gored by a bull and later died of his wounds. But, the death turns out to be the culmination of a months-long feud between Prajapati and the bull, centered around Prajapati's attempts to get the bull to stop sitting in front of the door to his house.

Prajapati threw a cup of hot water at the bull one morning. The next day, the bull came back and gored him. But that wasn't quite enough.

Much to people's surprise, the bull reached the hospital following Prajapati. Deepak Chourasia, a town-dweller, said that when the mortal remains of the old man were being consigned to flames the bull again sprang a surprise by arriving at the crematorium.

There is a minor history between Prajapati and the bull. Six month ago, the bull had attacked the old man after he hit the animal with a stick. Prajapati was at that time admitted to a hospital where he stayed for more than a month due to leg injury, Deori police station inspector R P Sharma told TOI.

Yesterday, I told you about how cows kill more people every year than sharks, even though sharks are (by far) the more-feared species. Today, let's look at this from the shark's perspective. Turns out, sharks are actually threatened ... by us. Yes, they have pointy teeth, but we have harpoons and nets.

In a 2010 article for Our Amazing Planet, Charles Q. Choi reported that as many as 1/3 of all shark and ray species in the world are at risk of dying out. Most of the deaths are accidental. Sharks can simply end up caught in nets meant for other animals. But there's also a thriving trade in shark fins and plenty of money to be made in allowing fishermen to hunt sharks for sport. Overall, humans intentionally kill upwards of 73 million sharks a year, according to a 2009 New York Times editorial.

READ MORE
Read the rest of the Times of India cow death story
Read Charles Q. Choi's piece on the risk of shark extinction
Read the New York Times editorial on the death of sharks
Read a 2007 interview with Jean-Michel Cousteau on the threat to sharks and how to save them.

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• Cow Kills Irish Pensioner

Cow-related death story via Alston D'Silva

Image: Cows, a Creative Commons Attribution Share-Alike (2.0) image from jelles's photostream

Shark cartilage may contain toxin linked to Alzheimer's, ALS —

If the cruelty involved in obtaining it isn't reason enough: Shark cartilage, a supplement hyped for purported use as a cancer preventive, joint-health aid, and other unsubstantiated health claims, "may contain a neurotoxin that has been linked with Alzheimer’s and Lou Gehrig’s disease." — Xeni •

The Australian blacktip shark lives in tropical waters. The common blacktip shark prefers its water subtropical and temperate. Because of the difference in habitat, these two animals have become separate subspecies with distinct physical differences.

However, there are some places where their habitats overlap. And here, along the eastern coast of Australia, there is interspecies nookie. And hybrid baby sharks.

Now, none of that is particularly shocking. Hybrid zones, where the habitats of two genetically compatible species overlap, aren't ridiculously common, but scientists have documented quite a few. What makes this finding interesting is that the two species and their hybrid have been genetically documented. Hybrid zones can be fuzzy places. What happens there calls into question how sure we can be that that what we call species really are all that different from one another.

What makes this study interesting is that researchers actually performed genetic testing on sharks caught in the hybrid zone. They found distinct genetic differences between the blacktip and Australian blacktip sharks, especially in their mitochondrial DNA. And the hybrids were identified based on genetics as well. That's something that's a lot more rare in the study of wild hybrids. The information gathered here could end up having a lot to teach us about how evolution happens and what speciation really means.

Via Mo Costandi

A vote for Shiffman is a vote for sharks (in a good way) —

College student bloggers from across the United States are currently competing to win a $10,000 scholarship. You can vote for the winner. And you should consider voting for David Shiffman, one of the ocean science bloggers who writes for Southern Fried Science. If he wins, he has pledged to adopt a satellite-tagged shark in the name of his blog's readers, hold a contest to name said shark, and provide regular blog updates about what the shark is up to. My suggestion: Vote Shiffman, because sharks are awesome. — Maggie •

Police in Milton, New Hampshire, found the carcass of a shark in woods more than an hour's drive from the sea.

Officers from the Milton police and New Hampshire Fish and Game were called, and after their investigation, decided to leave the shark where it was dumped and let nature take its course.

The mystery of Jabberjaw, who has not been seen since 1979, may finally be solved.

Milton police find shark in woods [WMUR]

This fearless lady pets a Great White like a dog as she hand-feeds it fish. [Video link: National Geographic via Metafilter]

The folks at the Marine Mammal Center in Sausalito, California do the work of heroes. Whenever a seal, sea lion, dolphin gets in trouble, the dedicated team of full-timers and volunteers head out and try to help. They heal and return to the wild a huge number of these wonderful animals. My family has been members for years and the hospital is a favorite place for my young daughter to visit. Today they released an awesome story of success: They used honey as an antibiotic to heal a shark bite wound on an elephant seal.

"Honey has gained recent popularity in both human and veterinary medicine as a wound treatment due largely to its natural healing properties. It has a very high sugar content and as a result binds water molecules strongly. That makes the water unavailable to organisms trying to make a living in the area. This is why honey can be safely stored on the shelf without refrigeration. Honey also contains a variety of compounds that may enhance the tissue response to infection and inflammation. It's less expensive than most topical antibiotic ointments and evidence suggests it is just as effective. So the Center's staff and volunteers cleaned the wound and applied a generous layer of honey to it. Thanks to both the honey and the tincture of time, Gupta's wounds healed very quickly. In fact, he was released on October 25 at Chimney Rock, Point Reyes National Shore, California."

"Gupta: Sweet As Can Bee!"

[via Etsy]

A new study conducted in Florida has given scientists reason to believe that hammerhead sharks may have vision comparable to that of humans. The researchers measured electrical activity in the eyes of half a dozen sharks from three different hammerhead species. They then put electrodes under the sharks' corneas and recorded electrical activity while shining lights in horizontal and vertical arcs around each eye. Compared to normal-headed sharks, the hammerheads had three times the visual overlap — that's what creates stereo vision and depth perception in animals with eyes that face forward. This, of course, helps them be faster and more efficient at hunting prey. But there's a catch: because their eyes are so far apart, hammerheads have these giant blind spots right in the middle of their head. As study leader Michelle McComb put it in an interview with National Geographic:

There's actually been anecdotal claims by divers that they see little fish schooling right in front of the hammerheads' heads. It's like the fish are swimming by and saying, Ha, ha, ha, you can't see me!

Hammerhead sharks have "human" vision [National Geographic] Image via Eric Charlton's Flickr