Blog Tags: Sharks
A study in the Journal of Experimental Biology made big news late last year by beginning to answer a fundamental, fable-like question: why are hammerhead sharks shaped the way they are? The answer, as it turns out? The better to see their prey with, my dear.
The researchers found some surprising results about hammerhead vision. One of those researchers, Michelle "Mikki" McComb of Florida Atlantic University, happens to also be an enthusiastic Oceana supporter. Mikki was kind enough to answer some questions about the research:
Can you summarize the conclusions you and your colleagues reached about hammerhead vision?
The popular literature is filled with claims that hammerheads have better vision, but this was never tested. Our goal was to quantify the extent of the visual fields of hammerhead sharks in contrast to more typical head shaped sharks, in order to determine if they possessed binocular vision.
The visual field is the entire expanse of space visible around the head and can be described by one eyes field of view (monocular field), two eyes field (cyclopean) and the overlap of the two monocular fields (binocular overlap). We determined the horizontal and vertical visual fields of three hammerhead shark species as well two closely related “typical” shaped sharks.
What we found was a surprise! Hammerhead sharks do have binocular vision, and even more surprising, the extent of binocular overlaps was greater than found in the “typical” shaped sharks. The largest binocular overlap was found in the winghead shark, the hammerhead with the widest head, and is a result of the positioning of the eyes on the end of the head.
Hey there ocean fans… are you ready for the NFL playoffs? No? Well even if you aren’t, the animals at the National Aquarium in Baltimore and the New England Aquarium sure are ready for the first round when the Baltimore Ravens play against the New England Patriots this Sunday afternoon.
Jen Bloomer, the Media Relations Manager for the National Aquarium and good friend of mine, just sent me an email with videos from each aquarium rooting for their respective teams.
Check out some of Baltimore’s other birds (Margaret and Louise) showing what they think the Ravens will do to the Patriots.
“We know the Ravens aren’t the only birds in town that like to destroy things,” Jen told me as we exchanged some pro-Ravens emails today. “Margaret and Louise love to show off for our visitors and the camera, and apparently love to support their fellow birds!”
Not to be outdone, the Harbor Seals at the New England Aquarium fired back with a message of their own.
Some consider the great white shark to be the fiercest predator in the ocean. Now Free Willy is giving the species a run for its money. Orca whales' diet traditionally includes fish, squid, birds, seals, and other whales. Now some are adding Jaws to the menu.
Several populations of orca whales have learned how to attack sharks, including the great white, with various techniques, including what some scientists are calling the “karate chop.” To execute this sly move, the orca drives the shark to the surface, then comes down on top of the shark and turns it upside down, at which point it enters a paralyzed state. In fact, all the attack methods ultimately end with the shark on its back.
If you want more, watch this recent video of one such showdown.
This week in ocean news,
...the International Commission for the Conservation of Atlantic Tunas approved next year's Atlantic tuna quotas, disappointing conservationists who say that only a complete closure of the fishery will allow the great fish to avoid collapse.
...scientists recommended a lower pollock quota this year in the North Pacific fishery, the largest in the U.S., as the population still struggles to rebound. Spawning levels are at their lowest in 30 years.
...in Japan, scientists photographed a juvenile coelacanth for the first time. Long thought to be extinct, these ancient creatures were rediscovered in the early 20th century and little is known about them.
...the U.S. Senate's Commerce, Science and Transporation Committee passed the Shark Conservation Act of 2009, which would require all sharks be landed whole in the U.S. and eliminate loopholes that allowed the transfer of fins at sea in order to get around shark finning laws. The vote brought the Act one major step closer to becoming law.
Have you ever tried to gift wrap a shark? Put a bow on a polar bear? Wrangle a penguin into a gift box? Thankfully, you don’t have to actually wrap up an animal to give an Oceana gift. I’m so excited to tell you that the Oceana Adoption Center is open for business!
All the familiar creatures are back this year - sharks, sea turtles, octopuses, polar bears, penguins, seals, dolphins and whales - and we've made a special addition too. We are now offering The Casey Kit, a deluxe limited-edition sea turtle adoption inspired by Casey Sokolovic, a young ocean hero who has been baking and selling cookies to support the rescue and rehabilitation of sea turtles.
Until wrapping paper comes in rolls large enough for a hammerhead, Oceana’s adoptions are the best way to give the ocean-lovers on your list the perfect holiday present. Make sure to order before December 15 to get free holiday shipping. Your tax-deductible donation is not only a thoughtful gift to a lucky friend or family member, but it helps us here at Oceana do our work – protecting the oceans all over the world.
- CEO Note: State Shark Fin Bans Protected Posted Wed, March 5, 2014
- Miranda Cosgrove Stars in New Oceana PSA to Save Dolphins Posted Wed, March 5, 2014
- The Economist’s Arctic Summit Convenes in London Posted Thu, March 6, 2014
- CEO Note: Seismic Airguns Threaten the Atlantic Posted Tue, March 11, 2014