Sharks can be trained like dolphins to feed from keepers, roll over and enjoy cuddles, according to new research.
In experiments carried out in the US some varieties of shark allowed
themselves to be picked from the water and cuddled.
Keepers at the UK's Sea Life Centres will now use the training techniques in
the hope that they will end up with hundreds of trained sharks.
The experts at the aquariums are to begin a period of intensive tuition by
using coloured boards and sounds to train the sharks in a similar way to
that used by the scientist Ivan Pavlov in training dogs.
It will mean that feeding becomes easier because each shark in a tank will
know when it is their turn to feed.
The Sea Life centres have many different types of shark and within just three
months the brightest ones should be responding to commands.
Sharks learn the signals then, when they see or hear them, they approach the
keeper who holds a "target stick".
The sharks then rub their noses against the stick and wait until they are fed.
No one had attempted to train sharks in this way before, but it could now
teach experts a great deal about the creatures.
Carey Duckhouse, of Sea Life, said: "The US team has shown that many
varieties of sharks can quickly learn to respond to a combination of audible
and visual signals.
"A shark answers its own sound and colour signal by putting its nose on a
target-stick held by the trainer, and keeping it there until it receives
food.
"Some species, such as zebra sharks, will even roll over to have their
tummies scratched or allow themselves to be lifted from the water without
any kind of struggle.
"The implications for improving shark welfare are enormous. It means when
we have to move them we can get the sharks to swim to a certain spot rather
than have to chase them around."
Taken off the coast of Mexico's Holbox Island by amateur photographer Sandra Critelli, this breathtaking picture captures the migration of thousands of rays as they follow the clockwise current from Mexico's Yucatan peninsula to western Florida.
Measuring up to 6ft 6in across, poisonous golden cow-nose rays migrate in groups - or 'fevers' - of up to 10,000 as they glide their way silently towards their summer feeding grounds.
These cow-nose rays (Rhinoptera bonasus) have distinctive, highdomed heads, giving them a curiously bovine appearance.
But even equipped with this powerful poisonous stinger, cow-nose stingrays are shy and non-threatening in large 'fevers'. Even when isolated, they will attack only when cornered or threatened.
Unlike other stingrays, they rarely rest on the seabed (where unsuspecting humans can step on them) and prefer to be on the move.
They migrate long distances, and can be found as far south as the Caribbean and as far north as New England.
They use their extended pectoral fins to swim, and often turn upside down, curling their fin tips above the surface of the water - leaving terrified swimmers convinced that they have seen a shark. :)
Their flexible fins also come in handy when rustling up food. By flapping them rapidly over the seabed, they stir up sand and reveal crabs, shellfish and oysters, which they then feed on using their powerful, grinding teeth.
Their particular fondness for shellfish has made them public enemy number one with oyster fishermen.
But despite this, their numbers are exploding, thanks in part to rising sea temperatures. They mate every winter, and females produce a litter of five to ten young.
Critelli said: ' It was an unreal image, very difficult to describe. The surface of the water was covered by warm and different shades of gold and looked like a bed of autumn leaves gently moved by the wind.'
The research team, writing in the science journal PLoS One, said they repeatedly observed a female dolphin herding cuttlefish out of algal weed and onto a clear, sandy patch of seafloor.
The dolphin, then pinned the cuttlefish with its snout while standing on its head, before killing it instantly with a rapid downward thrust and "loud click" audible to divers as the hard cuttlebone broke.
The dolphin then lifted the body up and beat it with her nose to drain the toxic black ink that cuttlefish squirt into the water to defend themselves when attacked.
Next the prey was taken back to the seafloor, where the dolphin scraped it along the sand to strip out the cuttlebone, making the cuttlefish soft for eating.
"It's a sign of how well their brains are developed. It's a pretty clever way to get pure calamari without all the horrible bits," Mark Norman, the curator of molluscs at Museum Victoria.
A separate 2005 study provided the first sign dolphins may be capable of group learning and using tools, with a mother seen teaching her daughters to break off sea sponges and wear them as protection while scouring the seafloor in Western Australia.
From Nature News.
A pack of killer whales uses waves to knock seals off the ice.
They made large waves to wash the seal off the relative safety of the ice. Later the orca put the seal back on the ice and dislodged the seal a second time which suggested strongly they were training their young.
It is not the first time a complex behaviour has been seen in just a few orcas. In the early 1970s, an orca was seen in Argentina beaching itself next to seals. At first it seemed to be in distress, but then it lunged at seals nearby, grabbed one by the neck, and dragged it back into the water. This beaching hunting technique has since been observed hundreds of times in Argentina among a small group of orcas. Studies have shown that the orcas can time their forays onto land to coincide with the tides, so they run less risk of becoming permanently beached.
Both the beaching and the wave hunting seem to be techniques that pod elders teach to younger animals. The Argentinean orcas have been seen nudging youngsters onto the shore, encouraging them to try the tactic, often coming up alongside to demonstrate. In the group at the Antarctic Peninsula, young orcas are often present during the hunt, and adults sometimes put living seals back on the ice after catching them, seemingly so that the young can have another try.
“This is orca culture,” says Visser.
Captured just before midnight on November 13 by fishers in Cambodia, this Mekong giant catfish is 8 feet long (2.4 meters long) ands weighs 450 pounds (204 kilograms).
"This is the only giant catfish that has been caught this year so far, making it the worst year on record for catch of giant fish species," said Zeb Hogan (far right), a fisheries biologist at the University of Reno in Nevada.
After collecting data on the fish, Hogan released it unharmed.
Giant catfish were once plentiful throughout Southeast Asia's Mekong River watershed, including the Tonle Sap River—home of the fish in these exclusive pictures taken near Phnom Penh.
But in the last century the Mekong giant catfish population has declined by 95 to 99 percent, scientists say. Only a few hundred adult giant catfish may remain.
Earlier this year Hogan launched the three-year Megafishes Project to document the world's giant freshwater fish.
Listed as critically endangered by the World Conservation Union, the Mekong giant catfish is big but toothless, as shown in this exclusive photo.
"For the Mekong giant catfish, northern Thailand is a spawning ground, whereas the Tonle Sap Lake in Cambodia is a rearing area," said U.S. biologist Zeb Hogan, who studied the fish pictured for his Megafishes Project, which is documenting the world's giant freshwater fish.
A bottlenose dolphin goes into labour . . . then a calf emerges, tail first. Mother guides baby gently to the surface, where they swim together for the first time.
Very few dolphin births have been captured on film in such astonishing detail.
This one was recorded at a wildlife park pool in Rimini, Italy, where photographer Leandro Stanzani was in exactly the right place at the right time.
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