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Friday Fishy News - January 26


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Happy Australia Day, Raiders!

Fish 'use logic to size up their rivals'


January 25

South Africa

London - Male fish, like humans, use a sophisticated form of logical reasoning to assess potential rivals, scientists said on Wednesday.

By watching how other males perform in battles over territory, tiny African fish called cichlids decide which opponent they should take on and are likely to defeat to improve their social standing.

The type of reasoning, known as transitive inference, is learned by young children. It has also been shown in primates and rats but scientists at Stanford University in California are the first to demonstrate it in fish.

"These results show fish do, in fact, use transitive inference to figure out where they rank in the social order," said Russell Fernald, a professor of biological sciences at the university.

"I was amazed that they could do this through vicarious experience, just by watching other males fight."

Male cichlids climb the social ladder by picking fights and defeating their opponents. Fish who are constantly defeated slump in the pecking order.

Fernald and his team, who reported their findings in the journal Nature, demonstrated transitive inference in fish by staging a series of experiments in an aquarium in which eight bystander fish watched others in battles.

They used a species of cichlid called Astatotilapia burtoni which displays a black stripe, or eyebar, on its face. If a fish is defeated in a battle it is easy to spot the loser because the eyebar disappears temporarily as it swims away from its victorious opponent.

When all the fighting was finished and the fish recovered from their losses, the researchers filmed the bystanders as they chose their potential opponent. They also recorded the amount of time they spent near them, which indicates their preference.

Nearly all the bystander fish selected the weakest fish.

"Our experiment shows that male cichlids can actually figure out their odds of success by observation alone. From an evolutionary standpoint, transitive inference saves them time and energy," Fernald said.

Male fish turn to cannibalism when unsure if paternity


January 20


A study from the February issue of the American Naturalist is the first to demonstrate that male fish are more likely to eat their offspring when they have been cuckolded during the act of spawning. Moreover, the more males that are present during spawning, the more likely it is that a male will try to eat the eggs when they are laid, as it is less likely that he fertilized them.

"The most drastic decision a father can make is to cannibalize his own offspring," writes Suzanne Gray (Ph.D. candidate at Simon Fraser University), Lawrence Dill (Simon Fraser University), and Jeffrey McKinnon (University of Wisconsin – Whitewater). "These results support and extend previous findings suggesting that confidence of paternity is a key factor in determining a male's behavior toward his offspring, including whether or not to eat them."

Predicted by theory, this pattern had never previously before been demonstrated. Studying Telmatherina sarasinorum, a small, colorful fish found in Lake Matano in Indonesia, the researchers found that females, who can be sure of their relationship to their eggs, never cannibalized. However, an increased level of cuckoldry led to an increased rate of cannibalism among males.

"We want to understand how behaviors evolve," says Gray, "and how behaviors, such as cannibalism, contribute to the diversity we see within and between different species."

Source : University of Chicago Press Journals

Fish doctors make a splash

By Christy Nicholson

Columbia News Service

January 20


NEW YORK — Dr. Gregory Lewbart found his latest patient to be a puzzling case. He arrived in Lewbart's office with a swollen eye and bloated stomach. Lewbart took X-rays, but saw nothing unusual. To be thorough, he decided to do an ultrasound.

Lewbart put the patient in a clear plastic bag with some water and held the ultrasound wand up to the bag.

Lewbart's patient was little more than the size of two nickels and had flowing red fins. It was a Siamese fighting fish named Rusty.

The vast majority of fish treated by veterinarians used to be the fancy tropical varieties, but vets are now treating the $1 goldfish brought home from a child's birthday party or won at the county fair. When a pet fish gets sick, concerned pet owners are discovering that top-notch help is available.

"The whole area has grown exponentially in the last 10 years," said Lewbart, also a professor of aquatic medicine at North Carolina State University. "Used to be people had to mail their sick fish to me. Now we have about 200 fish vets across the U.S. who see about two fish per week on average." It was not readily apparent whether fish vets practice in Missouri or Illinois.

Fish, by the way, "are very amenable to ultrasound," said Craig Harms, assistant professor of aquatic animal medicine at North Carolina State. "The probe can record through the water, and we get good, clear images."

In 1992, North Carolina State began the country's first residency program for fish medicine. Since then, the University of Florida has started its own residency program, and there now are medical fellowships focused solely on fish care.

Veterinarians remove tumors, use pins to repair broken fins, give CAT scans, implant glass eyes and even embed cork into the backs of fish to solve swimming problems. Costs for surgery can range from $75 to $1,000. X-rays cost $85, a CAT scan is about $300, and an MRI can cost up to $1,200.

In 2003, the first laser surgery on a pet fish was performed on a 4-ounce goldfish named Granny. Granny had an inch-long cancerous tumor on her skin. To prep her for surgery, the vets at North Carolina State put her into a tub of water mixed with anesthetic until she stopped moving. Then they placed her on a shallow tray and prodded her to ensure that she was sedated. During surgery they pumped water and anesthetic over her gills through a narrow rubber tube that fit inside her mouth.

Granny, who is now 5 years old, recovered well, and the cancer never returned. However, she recently developed a swimming disorder that left her floating upside down at the bottom of her tank. Like putting water wings on a 2-year-old, Lewbart attached a cork to Granny's dorsal fin. The cork keeps her afloat and right side up.

Buoyancy problems are common and can cause fish to float in alarming ways. Three years ago, Joann Mead found her daughter's goldfish, Raven, floating on the surface of the water, but still alive. Fearing her daughter would be upset to find Raven in such a condition, Mead contacted Helen Roberts, a fish veterinarian in Orchard Park, N.Y., and made the six-hour drive to her clinic. Roberts inserted a quartz stone inside Raven's swim bladder, weighing Raven down so she wouldn't float to the surface. The X-rays and surgery cost well over $200.

Mead said her friends told her she was crazy for spending so much time and money on a fish. But Mead feels she has a responsibility as a pet owner.

"Fin, feather or fur, there is a moral obligation to take care of that pet, no matter what," she explained.

Others take serious care of their fish not because they are pets but also because they enter the fish in fish shows, an increasingly popular pastime. Some spend up to $10,000 for prize-winning koi fish and are eager to keep their fish in top shape, said Galen Hansen of San Diego, who is one of the country's top judges of koi and an editor at Koi magazine.

For many, keeping exotic fish is a personal hobby. Michael Schinas of Tonawanda, N.Y., is spending $30,000 to build a 3,100-gallon indoor pond with an 8-foot waterfall to house his two Amazonian catfish as well as eels, baby swordtails and cichlids.

Of course, there are fish owners such as Jacob Braude of Maplewood, N.J., who would never spend money taking a fish to the vet. "There is no sign of affection from a fish," he said. "They come from a cold and wet world that is completely foreign. I can't touch them; their brain is small; and there's no real connection."

But many owners say that despite the water barrier, they form strong bonds with their fish, and their pets become members of the family, each with a distinct personality.

Schinas said his red-tailed, 10-pound catfish, Gracie, swims over to him as soon as he walks in the door. "She'll wag her tail and move her whiskers, and you get the impression she's happy," Schinas said.

For Schinas, Gracie is more than just a hobby. When bacteria stripped her of her scales and made her look as though she had been filleted, he paid Roberts to make several house calls to inject Gracie with antibiotics. The treatment cost $1,500, but Gracie is cured, and Schinas is relieved.

Granny's owner is similarly attached to her fish. "She can see me if I wave from across the room," said Amanda Willis of Greensboro, N.C. "I kiss her through the glass, and I get a real sense we are communicating."

Kelly McDaniel from Myrtle Beach, S.C., who owned Rusty the Siamese fighting fish, grew up around dogs and never understood people who kept fish as pets.

"I always thought fish were for weird people," she said. "Why would anyone want a fish?"

But last Christmas, a co-worker bought her a little betta called Buffy, and in a matter of weeks she was hooked. She bought more bettas, including Rusty, and she was surprised at how much personality each fish displayed.

"As soon as I'd come within five feet of Rusty's tank, he'd start dancing," she said. "He'd whip up to the top of the tank for me to pet him."

So when his stomach puffed out as if he had swallowed two marbles, she packed him up and made the three-hour drive to Lewbart's offices at North Carolina State.

"If someone told me I'd be getting an ultrasound done on a pet fish, I'd have thought they were loony tunes," McDaniel said.

The doctors tried everything to save Rusty. They ruled out tumors, tried countless antibiotic dips and constipation relief, and even used Epsom salts in an attempt to draw fluid from his stomach. Nothing worked.

That week, Rusty hunkered low in a corner of his tank. Knowing he was getting worse, McDaniel stayed up all night to console him. But at 4 a.m. when she went to check on him, she saw that he had died.

"I told him I loved him and that I had tried everything to take care of him," she said. "But he was suffering and wasn't himself. As much as I didn't want him to go, I didn't want him to linger; I didn't want him to suffer any longer."

Increasing appetite for live fish stripping Asian reefs bare

By Dikky Sinn

The Assocaited Press

January 23


The rising demand for live reef fish by seafood-hungry diners in Greater China has for the first time been shown to have decimated endangered species around Asia, a study released Wednesday said.

Researchers studying the trade in Malaysia, formerly home to some of Asia's most abundant coastal reefs, found that catches of some grouper species and the Napoleon wrasse fell by as much as 99 percent between 1995 to 2003, a period coinciding with the rapid economic growth of countries where such exotic fish are a delicacy.

"The removal of these large, predatory fish might upset the delicate balance of the coral reef ecosystem," said Helen Scales, who co-authored the study for the Swiss-based World Conservation Union, appearing in the online edition of Proceedings of The Royal Societies, a respected scientific journal.

"With all the threats the reefs already face, these fishing practices take us one step closer to losing these reefs," Scales said.

The study of daily fish catches and sales quantifies what conservationists have said for a decade — that hunger for live reef fish in Hong Kong, Taiwan and mainland China is causing populations of wrasse, grouper and coral trout on coastal reefs to plummet in Malaysia, Indonesia, the Philippines and Papua New Guinea.

The United Nations and the World Conservation Union released a report last year warning that human exploitation of the high seas was putting many of its resources on the verge of extinction.

It noted that 52 percent of global fish stocks are over harvested and that populations of the largest fish such as tuna, cod and swordfish declined as much as 90 percent in the past century.

It also said destructive fishing practices — including bottom trawling, illegal longline fishing and a rise in large industrial vessels — have led to the deaths of tens of thousands of seabirds, turtles and other marine life.

"Well over 60 percent of the marine world and its rich diversity found beyond the limits of national jurisdiction is vulnerable and at increasing risk," Ibrahim Thaiw of the World Conservation Union said in a statement last year.

Reef fish — which are caught mostly by small fishermen who sometimes using cyanide to stun their catch — are prized mostly because they are cooked live. Traders are careful to ensure they arrive that way, packaging them in bags of water and placing them in white coolers for a trip that often takes them thousands of kilometers (miles) to seafood restaurants that resemble aquariums.

Diners stroll past bubbling tanks stuffed full of fish that can cost as much as US$100 (€77) a kilogram (2.2 pounds).

"Most Hong Kong people now choose to eat grouper because of the firm flesh. It's tastier," said Ng Wai Lun, a restaurant owner in Hong Kong, which consumes the most reef fish of any city. "Farmed fish is less tasty and fresh."

Some go closer to the source. Kerry To, a Hong Konger, flew to Malaysia for a holiday to enjoy a meal of steamed grouper in Kota Kinabalu, a few hours away from key reef fishing grounds.

"These fish are so big and taste so good. I'll be telling my friends," said To, 45, tucking into a meal of steamed fish with a dozen other Hong Kong tourists.

The World Wide Fund for Nature's Annadel Cabanban, who studies the trade in Malaysia, agreed with the study's finding that the numbers of reef fish were on the decline due to increasing human demand.

She said destructive fishing practices — namely explosives and the use of cyanide over the past 10 years — were as much to blame for the decline as overfishing because they destroy crucial reef habitats, affecting reproduction.

"There are no predators to check the fish that eat the plants and the shellfish," Cabanban said. "There is a cascading effect on the reef. With so many herbivores, the plant population declines and fish run out of food and they die."

Scales, the study's co-author, said it was impossible to quantify how many fish were taken by explosives or cyanide because fishermen refuse to discuss it.

Conservationists fear that the growing demand for live fish — an industry worth more than US$1 billion (€773,000) a year — is adding pressure to coral reefs already threatened by warming oceans, development and pollution.

Eighty-eight percent of Southeast Asia's coral reefs face destruction from overfishing and pollution, the U.S.-based World Resources Institute estimates. Most under threat were the Philippines and Indonesia, home to 77 percent of the region's nearly 100,000 square kilometers (40,000 square miles) of reefs.

Fishermen in Kudat — a sleepy South China Sea port in Malaysia that depends almost entirely on fishing — acknowledged that catches have declined. Their boats now travel to the neighboring Philippines to find prized reef fish.

The fishermen argue that there are plenty of fish and that they have few options.

"This is our livelihood," said Ismail Noor, 45, adding that he sometimes spends three days at sea in search of the fish. "If we stop, we would have no income."

Noor and his fellow fishermen insist they use only hooks and lines or nets. But the local fisheries department said the use of explosives remains widespread, despite campaigns that warn of the dangers of losing arms, legs and hands.

"Most villagers are stubborn and have always done bombing since they were children," said fisheries official A. Hamid Maulana. "It is difficult to change attitudes."

Conservationists say the answer is to establish international standards for managing the import and export of reef fish. They also said consumers must be educated about the need to avoid certain endangered fish and promote captive breeding.

So far, no international body has been willing to endorse standards commissioned by the Asia-Pacific Economic Cooperation forum, a group of Pacific Rim governments, that would ban explosives and cyanide in fishing, boost monitoring and enforcement, and label fish caught by conventional means so they could fetch a premium price.

"Traders are interested in ensuring they have a constant supply of product," said Geoffrey Muldoon, an Australian expert who helped write the standards. "Their idea of a constant supply is not to say we have to protect this area, but that we need to find a new area because we have fished this one out."


Edited by Flattieman
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Some goodies there tonight Flattieman..Hmmm..a fish vet..Only in America eh?

Taking your sick goldfish to the vet and coughing up loads of $$$ is not something I would do I'm afraid.

A quick flush and go buy another.



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