scientist shark

After four years alone, female shark has babies without a male mate

  • Leonie, a female zebra shark in Australia, had three offspring in early 2016 after being completely isolated from males for roughly four years.
  • According to New Scientist, Leonie was first paired with a male at an Australian aquarium in 1999; the couple had over two dozen babies.
  • In 2012, aquarium staff moved Leonie’s partner to another tank, leaving her alone— which is why scientists were stunned when she gave birth.
  • How did it happen? It could be because of a kind of biological contingency plan for if there are no male sharks around.
  • According to New Scientist, sharks are capable of asexual reproduction if there’s a genetically identical cell called a sister polar body nearby to fertilize it.  Read more

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smithsonianmag.com
Canadian Scientists Explain Exactly How Their Government Silenced Science
It wasn’t just climate research. Rock snot, sharks and polar bears: All were off-limits during the Harper administration
By Joshua Rapp Learn

“A survivor’s guide to being a muzzled scientist.”  

Get a personal e-mail address, start your own blog and make sure there are multiple copies of your datasets. “Get anonymous, get online. Let people know what’s going on,“ Rennie says. “Folks that are in academia, that have tenure, that have a bit more job security and have more of an ability to speak their mind can help those in the public service that are challenged with these situations.”

“Disservice is too mild a word” to describe the effect of this muzzling, says Steven Campana, a shark scientist who spent 32 years working for Canada’s Department of Fisheries and Oceans:

 “It’s a cheat for the taxpaying public because it’s the taxpaying public that is funding this government research. When that research leads to very positive things, or even if it’s negative, the people that paid for it deserve to hear about it.”

Source: Smithsonian Magazine

Meet the Extremely Rare Pocket Shark

Museum scientists are getting an up-close look at an extremely rare—and extremely small—shark by taking high-resolution, three-dimensional x-ray scans.

National Oceanic and Atmospheric Administration (NOAA) researchers were trawling in the Gulf of Mexico for a sperm whale feeding study in 2010 when they inadvertently pulled up a tiny, odd-looking shark with a bulbous head and rows of sharp teeth. NOAA researchers subsequently identified the creature as the rare pocket shark (Mollisquama sp.). The specimen is only the second ever collected, 36 years after the first one was found off the coast of Chile.

Named for two small openings above its pectoral fins, the pocket shark is still mostly a mystery, as is the purpose its pockets serve. But instead of dissecting this rare 5.5-inch-long specimen, scientists have turned to non-destructive x-ray techniques: computed tomography (CT) scanning in the Museum’s Microscopy and Imaging Facility and at the European Synchrotron Radiation Facility (ESRF) in France.

“The level of detail we can achieve through x-ray imaging is just incredible,” says John Maisey, a curator in the Museum’s Division of Paleontology who has been working with NOAA researchers and Museum Axelrod Postdoctoral Fellow John Denton to scan the specimen. “It allows you to look at these priceless specimens in a way you couldn’t have 10 or 15 years earlier.”

The CT scans proved especially valuable for counting the vertebrae of the pocket shark, the smallest of which were too small to be picked up using standard x-ray imaging, and for counting the teeth. Many of the specimen’s teeth were missing, but by rotating the image of the jaw and examining its inner surface, researchers were able to count the tiny new teeth coming up to take their place.

The species appears to be closely related to cookie cutter sharks, which feed by taking bites out of the skin of larger animals. And the anatomy of the pocket shark’s jaws and teeth indicate that it inhabits a similar ecological niche. 

As for the shark’s mysterious pockets, one working hypothesis is that that they might emit a bioluminescent fluid to either attract mates or to confuse predators. Maisey and Denton are now poring over the extremely high-resolution scans taken at ESRF with Mark Grace, the biologist with NOAA’s Southeast Fisheries Science Center who discovered the specimen, to learn more about their anatomy.  

But anything gleaned from the scans will likely remain hypothetical until scientists can observe a pocket shark in action.

“I would love to see a pocket shark alive in its environment,” Grace says. “But the CT scans are the next best thing.”

This story was originally published on the Museum blog. 

Eugenie Clark, whose work in the field of marine biology was absolutely groundbreaking, passed away this morning at the age of 92.

Not only did she make countless discoveries about many species of fish. Not only was she one of the first scientists to believe that sharks were more than mindless killers, and publish numerous studies demonstrating the complexity and intelligence of the incredible creatures. Not only was she a huge advocate for them, constantly working to teach the public about how amazing sharks, and all ocean creatures are, and how important it is that we actively work to protect them.

She was a woman marine biologist at a time when the field was almost completely dominated by men, but she never let anyone stop her from achieving her dreams. (When she applied to a Ph. D. program at Columbia, she was told by a scientist there, "If you do finish, you will probably get married, have a bunch of kids, and never do anything in science after we have invested our time and money in you.“ She then went on to get her Ph. D. elsewhere, and do many, many things in science.)

She founded a laboratory, first called the Cape Haze Marine Laboratory, which then went on to become the Mote Marine Lab, one of the most important centers for shark research in the countries.

She literally changed the game in marine biology. But she was also just an incredibly kind, curious, and bold individual, who always sought to inspire young scientists and ocean activists.

Eugenie Clark was my hero as a child, and honestly, one of the reasons I’m pursuing a career in science. I had the absolute honor of meeting her (twice!!) and she was so, so, so incredibly kind to me, giving me words of encouragement, talking to me about my interests, and just truly, being one of the most humble, intelligent people I’ve ever met.

She changed my life, and I am so grateful to have had the chance to both know about her, read about her life and her work, and to talk to her.

At some point in Ichthyology
  • Fish Scientist 1: what are we gonna call this species of shark with spots?
  • Fish Scientist 2: leopard shark?
  • Fish Scientist 1: no that's already taken.
  • Fish Scientist 2: how about zebra shark?
  • Fish Scientist 1: do zebras have spots?
  • Fish Scientist 2: idk who cares? No one will notice.
Shark Week to include actual science and shark facts this year.

Scientists agree that Shark Week hit rock bottom a couple of years ago with a Megalodon special that appeared to be a documentary—unless that is, you read the three-second disclaimer that it was fake at the outset of the show. Most people didn’t. Shark ecologist David Shiffman told NPR that “Shark Week two years ago did not appreciate it when I recommended an eight-year-old neighbor fact-check scripts for them. Because that eight-year-old knew more about sharks than whoever was writing those scripts…” 

The cacophony of outraged researchers calling on the network to instill a touch of accuracy back into its programming made its mark: Discovery Channel’s new president announced last week that this year, shows will focus on shark research. It’s definitely progress, but stay tuned to Shiffman, @whysharksmatter, on Twitter to make sure you’re not being duped by fear mongering faintly disguised as fact. 

Originally posted by rminerva

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Celebrate National Cookie Day with the cookiecutter shark!

Cookiecutter sharks take neat bites out of much larger animals, leaving their prey wounded, but alive. These sharks are difficult to study, because they live in the dark ocean depths, at least 330 feet (100 meters) down. But by examining specimens caught in nets, scientists have found they have specialized teeth, and lips that protrude to form a suction cup. 

Cookiecutter sharks bite into large animals such as swordfish, tunas, porpoises and seals, leaving circular wounds. The jaws of a cookiecutter shark bear 25 to 32 rows of sharp, pointed teeth. The bottom teeth are large and triangular, like saw teeth, while those on top are small and thin. Scientists think the shark slices into its prey with the strong bottom teeth, rotating to cut out a cookie-shaped mouthful of meat. Like other sharks, they hunt by electrosensing and have been known to gouge undersea cables that they mistake for prey.

Meet many more unusual creatures in Life at the Limits: Stories of Amazing Species, open through January 3 at the Museum. 

Images: Wikipedia

Eugenie Clark, an icon in marine science, died last week at the age of 92. A sweet piece from NPR remembers how she was dropped off at the aquarium on Saturdays by her widowed working mother, and went on to essentially create shark research over the course of her 75-year career. On the wall of heroes the Shark Lady goes. —Perrin

Thoughts on Shark Week 2015

This year’s Shark Week was so much improved! There was a much higher focus on science, biodiversity and conservation, and a lot less sensationalism and pseudoscience. So if you had decided to not tune in this year after last year’s disappointments, I advise you to give it a try! I have listed below some of my favorite episodes that really are worth the watch. 

Originally posted by leonettaisas

This 3rd installment of Alien Sharks was incredible. I am still slightly obsessed with this episode. I could feel the rush of adrenaline as they were tagging the megamouth shark just sitting on my couch! SO.MUCH.SCIENCE. I loved it! I learned about biofluorescence (i have to make a separate blog post about that) which I honestly didn’t even know existed until then! The megamouth (I also have to make a separate blog post about that!) expedition was just insane. Can we get a follow-up on that once the tag gets released? I’m not sure when they tagged the shark/when this episode was filmed. I need to know the results! 

Sharks of Cuba was also one of my favorites. It focused on a joint U.S.-Cuban team of scientists studying the sharks of Cuba. The area they were in really goes to show how wonderful Marine Protected Areas are. The reefs there were gorgeous, and the silky sharks and remoras shown on screen were huge! You could tell the ecosystem around the island is thriving, undisturbed. We got to see the first tagging of a shark in Cuba, as well as the tagging of a rare longfin Mako! 

Ninja Sharks are also incredible. I LOVE learning about all those more ‘obscure’ sharks, like the Salmon shark and Thresher shark, and what their ‘ninja’ skills are. Loved all the graphs and scientific facts! Shark Planet was a 2 hour recut of the BBC Earth "Sharks" series, and it was AWESOME. I mean, we all know the BBC wildlife documentaries are incredible, so I wasn’t expecting anything less. We saw so many shark species, and some shark behavior that we never really saw before (epaulette sharks walking across land, what?!). 

Originally posted by coloredyouth

Overall, I was quite satisfied with this year’s show. There were still some very low lows (a Great White serial killer? “Oh there were two attacks 2 years apart right here so this must be the same shark”), but also some very high highs (ALIEN SHARKS!), and a lot of good things in between. 

Here is my personal list:

The AMAZING:  Alien Sharks, Ninja Sharks, Sharks of Cuba, Planet Shark

The Good:  Monster Mako, Shark Trek, Shark Clan

The Meh Okay:  Island of the Mega Shark, Bride of Jaws, Shark Island, Shark of the Shadowlands

The Bad: Super Predator, Return of the Great White Serial Killer

Shark Week definitely really needs to keep steering away from the speculation and sensationalism of Super Predators and Serial Killers and shark bite reenactments. I wish for less Great White Shark drama (although you may continue the Shark Trek series), and more endangered, rare and weird species (Salmon shark! Thresher Shark! Megamouth!! Yes please).  I give you two thumbs up, Discovery Channel, for moving in the right direction and turning this program around! Keep it going, and I look forward to next year.

Originally posted by tessasmile

Neonate blacktip shark (Carcharhinus limbatus)

This is the first neonate blacktip we caught for our research, and she was also our smallest shark. She measured under 60 centimeters for total length and only weighed about half a kilogram. Her umbilical scar was completely open, indicating that her birth occurred within the last two weeks.

After taking measurements and collecting blood and muscle tissue samples, she was released back into the sound.

Artificial insemination produces 2 baby sharks debuting at aquarium

The two new zebra shark pups at the Aquarium of the Pacific won’t be on display until Tuesday, but the reason they hatched is already causing quite a stir at the facility.

Long Beach’s aquarium is the first to successfully reproduce zebra sharks through artificial insemination, according to aquarium scientists. The baby female sharks are a hopeful sign in the face of dwindling shark populations in the wild.

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Have you heard of the pocket shark?

Museum scientists are getting an up-close look at this extremely rare—and extremely small—shark by “dissecting” it digitally. 

Learn more about the pocket shark.