Wonder how the Spanish dancer, or Hexabranchus sanguineus, got its common name? When it swims, the frilled edges of its mantle resemble the color and movement of the skirts of a flamenco dancer.
When they're not swimming, Spanish dancers crawl along relatively flat surfaces with the edges of their mantle tucked up close to their bodies (see the picture). They feed on sponges and can produce a toxic chemical to protect themselves from predation.
Today’s Oil Spill Quote of the Day features Elizabeth Griffin Wilson, one of our very own scientists:
From yesterday’s Guardian:
Some 1,020 sea turtles were caught up in the spill, according to figures (pdf) today – an ominous number for an endangered species. Wildlife officials collected 177 sea turtles last week – more than in the first two months of the spill and a sizeable share of the 1,020 captured since the spill began more than three months ago. Some 517 of that total number were dead and 440 were covered in oil, according to figures maintained the Deepwater Horizon response team.
Of the approximately 100 species of cuttlefish, the Australian giant cuttlefish is the largest cuttlefish in the world. They can grow almost five feet long and weigh almost 30 pounds.
The coolest thing about these colossal cephalopods is their ability to change color for a number of reasons, including aggression, excitement, camouflage, or mating. They can change color so effectively that they can become almost entirely invisible when hiding among rocks and in caves. When they want to be noticed, they can put on a brilliant display of colors and flashes, particularly during the winter mating season.
From today's Washington Post:
The government said last week that three-quarters of the spilled oil has been removed or naturally dissipated from the water. But the crab larvae discovery was an ominous sign that crude had already infiltrated the Gulf's vast food web - and could affect it for years to come.
"It would suggest the oil has reached a position where it can start moving up the food chain instead of just hanging in the water," said Bob Thomas, a biologist at Loyola University in New Orleans. "Something likely will eat those oiled larvae ... and then that animal will be eaten by something bigger and so on."
Tiny creatures might take in such low amounts of oil that they could survive, Thomas said. But those at the top of the chain, such as dolphins and tuna, could get fatal "megadoses."
The final FOTD for Shark Week is on the fascinating great white shark, or white shark. Despite their reputation as man-eaters, great white sharks are actually more threatened by humans than vice versa.
From NPR.com today:
"It's actually round two of psychological trauma for these communities, who also in the back of their minds are already worried about hurricanes this season," said [president of the Children’s Health Fund, Dr. Irwin] Redlener, who plans to bring doctors to the Gulf in the next few weeks to provide physical and mental care for the children who are suffering nightmares or other stress, or who have rashes, breathing problems or other physical effects from the spill.
Today’s FOTD is about the beautiful zebra shark. These sharks get their name from the impressive stripes found on the juveniles.
As they grow into adulthood, these stripes change into spots, which is why this shark is occasionally also called the leopard shark. (Taxonomists even originally thought that juvenile zebra sharks were actually a different species than the adult zebra sharks because their markings are so different!)
From yesterday's New York Times:
Federal scientists and coastal residents agree in at least one respect: that the long-term effects of the spill are unknown, and that it is too early to make any conclusions about the true scale of the damage. That uncertainty leads to perhaps the most potent source of skepticism: a deep anxiety about the region’s economic future.
From yesterday’s Washington Post:
BP's well was gushing faster than expected, government experts said. The latest estimate pegs original "flow rate" at 62,000 barrels a day (2.6 million gallons), higher than the last estimate of 35,000 to 60,000 barrels. As the reservoir was depleted, the rate was reduced to 53,000 barrels a day. They calculated the total oil coming from the blown-out well at 4.9 million barrels, more than 18 times the amount of oil that was spilled during the Exxon Valdez disaster.
Today’s FOTD is brought to you by the letter C, which is for cookie…and cookiecutter shark.
Unlike most of the other sharks I’ve written about so far, the cookiecutter shark is a relatively small shark; they only reach about 20 inches in length. Like some other sharks, such as great white sharks, female cookiecutters are larger than their male counterparts.
Despite their small size, these sharks still have quite a bite. They latch onto their prey and create suction with their large lips. Then they use their powerful jaws and many teeth to carve a circular chunk of flesh out of the unlucky victim. (Get it? Like a carnivorous, marine cookiecutter?)
Cookiecutter sharks attack large fish like tuna or even whales and dolphins; the prey usually survives the attack but the telltale round scar remains. They are also bioluminescent; they have a patch on their bellies that glows in the dark, deep waters where they live. They use their bioluminescence to attract potential prey.
See you tomorrow for another shark FOTD and I hope you’re enjoying Shark Week as much as I am!