New Armored, Wood-Eating Catfish Found in Amazon

Very interesting….detailed description as follows…

Wood-Eating Catfish … Eating Wood

A new species of armored, wood-eating catfish (pictured underwater) found in the Amazon rain forest feeds on a fallen tree in the Santa Ana River in Peru in 2006.

Photograph by Michael Goulding/Copeia

Other so-called suckermouth armored catfish species use their unique teeth to scrape organic material from the surfaces of submerged wood. But the new, as yet unnamed, species is among the dozen or so catfish species known to actually ingest wood.

Still, wood-eating catfish are largely unable to digest wood. Only associated organic material—such as algae, microscopic plants, animals, and other debris—gets absorbed into their bodies. The wood itself passes through the fish and is expelled as waste.

“The fish pass wood through their guts in less than four hours, which is incredibly fast for an animal that supposedly digests wood,” said Donovan German, a biologist at the University of California, Irvine, who is researching the digestion of wood-eating catfish.

“People think they must have an amazing consortium of microbes in their guts to help the fish digest wood, but that isn’t really what I’ve found,” he added. “The amazing microbes are in the river, on the wood itself.”

Fresh Catch

Photograph courtesy Paulo Petry

Nature Conservancy scientist Paulo Petry holds up a rare whole specimen of a newly identified species of wood-eating catfish, netted by Peruvian biologist Roberto Quispe at the confluence of the Alto Purús and Curanja Rivers in summer 2010.

According to the University of California’s German, who wasn’t involved in the new study, previous specimens “were dried by the people who caught them, so all that was available were these large dried specimens or smaller individuals.”

While the unnamed species is new to science, the fish is a familiar food to indigenous people of the Amazon, especially in Peru (Amazon interactive map).

“They put it in soup or barbecue it whole,” German said. “The fish have an armor shell that acts like a built-in bowl. So they take out the gut and cook the fish whole and just eat the meat out of the shell.”

Most wood-eating catfish belong to the genus Panaque, as does the new species, which can grow at least 2.5 feet (80 centimeters) long.

Mouth of Wood-Eating Catfish

A member of the new species of armored, wood-eating catfish—netted in the Peruvian Amazon in summer 2010—shows off the spoon-like teeth and suctioning lips that help the fish gouge out log shavings.

Photograph courtesy Paulo Petry

Wood-eating catfishes’ unique diet likely evolved due to competition with other catfish species for food in the Amazon Basin rivers, researchers say.

“There’re not a lot of rocks in the Amazonian Basin, where these fishes live,” German said. “There’s mud and water, and the one consistent substrate at the bottom is wood. It’s the one place where fish can go to get food off a surface.”

There are about 700 species of catfish that survive by scraping organic material from surfaces, including wood, in the Amazon Basin. But by actually ingesting the wood, wood-eating catfish take advantage of the organic matter, microbes, and microbial byproducts that reside in the spaces between wood fibers.

“The ability to dig and gouge then becomes advantageous,” German said, “because now you can get to all these other goodies that surface eaters can’t get.”

Jaws of Wood-eating catfish

The four stout jaws of the new wood-eating catfish species are clearly visible in this 3-D image of its head, which was made by sticking the fish into a specialized CT scanner.

Diagram courtesy Nathan K. Lujan and Julian Humphries

“Once they latch on with their lips, they can move those teeth around in all sorts of different directions to grind up the wood,” German explained.

“They’re not ingesting giant splinters. It’s mainly small shavings and particles of wood, along with microbes and whatever byproducts the microbes are making available as they degrade the submerged wood.”

Holotype Characters

Adult male members of many wood-eating catfish species—such as this specimen of the new species, caught in Peru in 2006—have bristly appendages on their fins and on their heads.

Diagram courtesy Max Hidalgo and Nathan K. Lujan

“The brushlike features are specialized teeth called odontodes,” said Texas A&M University biologist Nathan Lujan, lead author of the study describing the new species. “They are used in sexual and territorial threat displays.”


Tahukah anda? 6 – Ikan airtawar terbesar di dunia

Pada August 2007, ikan keli gergasi Mekong (Mekong Giant Catfish) seberat 646 pounds (293 kg) direkodkan sebagai ikan airtwar terbesar di dunia. Ikan ini berjaya ditangkap di Air terjun Khone di Laos, berhampiran dengan sempadan Cambodia. Ikan ini juga tersenarai sebagai ikan yang sangat terancam oleh the World Conservation Union.

Jika projek pembinaan empangan Khone menjadi kenyataan, Mekong Giant Catfish ini berkemungkinan besar akan pupus….

April 8, 2008—Children pose with a Mekong giant catfish caught at Khone Falls in Laos, near the border with Cambodia, in August last year.

While the weight of the fish in the photo is unknown, the species holds the world record as the largest freshwater fish ever caught, weighing in at 646 pounds (293 kilograms).

The Mekong giant catfish is listed as critically endangered by the World Conservation Union.

But a new dam project planned for Khone Falls threatens the migration of this so-called megafish, according to Zeb Hogan, who heads the National Geographic Society’s Megafishes Project.


Makanan alergi

Sesetengah makanan memang alergi kepada sesetengah orang, dan ini pun boleh dianggap sifat warisan/keturunan.

Apakah beza antara makanan alergi dengan makanan yang tidak boleh dimakan?

Selalunya makanan alergi ini ialah makanan yang dimakan yang akan menyebabkan badan bertindak balas dan menghasilkan tanda-tanda seperti ruam, kulit gatal, tidak sedap perut, dan lain-lain reaksi badan. Sebaliknya, makanan yang tidak boleh dimakan ialah makanan yang tidak boleh diterima oleh sistem penghadaman, yang mungkin menyebabkan muntah, pening, dsb.

Simptom yang ditunjukkan oleh makanan alergi ini berbeza-beza, dari ringan hingga kes berat, sehingga ada yang menyebabkan kematian.

Selalunya sendiri tahu dan boleh merasakan apakah jenis-jenis makanan alergi bagi diri masing-masing. Ini selalunya melalui pengalaman sejak kecil, namun begitu ada juga yang berubah tahap alerginya terhadap makanan tertentu. Kebanyakan makanan yang menyebabkan alergi ialah berasaskan protein, iaitu kekacang, makanan laut, dsb.

Untuk mengetahui lebih lanjut tentang makanan alergi, di bawah ini diperturunkan maklumat tersebut….

Food Allergies

This topic has general information about food allergies.

What is a food allergy?

When you have a food allergy, your body thinks certain foods are trying to harm you. Your body fights back by setting off an allergic reaction. In most cases, the symptoms are mild-a rash, a stuffy nose, or an upset stomach. A mild reaction is no fun, but it is not dangerous. A serious reaction can be deadly. But quick treatment can stop a dangerous reaction.

Allergies tend to run in families. You are more likely to have a food allergy if other people in your family have allergies like hay fever, asthma, or eczema (atopic dermatitis).

Food allergies are more common in children than adults. About 7 out of 100 kids have them. Only about 3 to 4 out of 100 adults do. Children often outgrow their food allergies. But if you have a food allergy as an adult, you will most likely have it for life.

What are the symptoms?

Food allergies can cause many different symptoms. They can range from mild to serious. If you eat a food you are allergic to:

* Your mouth may tingle, and your lips may swell.
* You may have cramps, an upset stomach, or diarrhea.
* You may have itchy skin with red, raised bumps called hives .
* You may have a stuffy nose, wheeze, or be short of breath.
* You may feel dizzy or lightheaded.

Kids usually have the same symptoms as adults. But sometimes a small child just cries a lot, vomits, has diarrhea, or does not grow as expected. If your child has these symptoms, see your doctor.

Some people have symptoms after eating even a tiny bit of a problem food. As a rule, the sooner the reaction begins, the worse it will be.

The most severe reaction is called anaphylaxis (say “ANN-uh-fuh-LAK-suss”). It affects your whole body. Anaphylaxis usually starts within an hour after you eat the food. And the symptoms can come back 1 to 2 hours later. If you have anaphylaxis:

* Your throat and tongue may swell quickly.
* You may suddenly start wheezing or have trouble breathing.
* You may feel sick to your stomach or vomit.
* You may feel faint or pass out.

Anaphylaxis can be deadly. If you have (or see someone having) any of these symptoms, call 911right away.

What foods most often cause a food allergy?

A few foods cause most allergies. A food that causes an allergy is called a food allergen. Usually it is the protein in a food that causes the problem.

* Eggs, milk, wheat, soy, and peanuts cause most problems in children. Most kids outgrow allergies to eggs, milk, wheat, and soy by the time they are 5. But while 1 out of 5 of kids outgrow an allergy to peanuts, they rarely outgrow an allergy to tree nuts (like walnuts or almonds) or seafood.

* Peanuts, tree nuts, fish, and shellfish cause most problems in adults. Most adults who have food allergies have had them since childhood.

If you are allergic to one food, you may also be allergic to other foods like it. So if you are allergic to shrimp, you may also be allergic to lobster or crab.

How is a food allergy diagnosed?

Your doctor will ask questions about your medical history and any family food allergies. And he or she will do a physical exam. Your doctor will also ask what symptoms you have. He or she may want you to write down everything you eat and any reactions you have.

If your doctor thinks you could have a serious food allergy, you may have a skin test. The doctor will put a little bit of liquid on your skin and then prick your skin. The liquid has some of the possible food allergen in it. If your skin swells up like a mosquito bite, your doctor knows you are allergic to that food. Your doctor may also do blood tests to look for the chemicals in your blood that cause an allergic reaction.

How is a food allergy treated?

The best treatment is to never eat the foods you are allergic to. Learn to read food labels and spot other names for problem foods. For example, milk may be listed as “caseinate,” wheat as “gluten,” and peanuts as “hydrolyzed vegetable protein.” When you eat out or at other people’s houses, ask about the foods you are served.

If you do eat a food you are allergic to, medicines can help. You may be able to stop a mild reaction by taking over-the-counter antihistamines. You may need prescription medicines if over-the-counter drugs do not help or if they cause side effects, such as making you feel sleepy.

you have severe food allergies, your doctor will prescribe an allergy kit that contains epinephrine (say “eh-puh-NEH-fren”) and antihistamines. An epinephrine shot can slow down or stop an allergic reaction. Your doctor can teach you how to give yourself the shot.

You can have symptoms again even after you give yourself a shot. So go to the emergency room every time you have a severe reaction. You will need to be watched for several hours after the reaction.

If you have had a serious reaction in the past, your chance of having another one is high. Be prepared.

* Keep an allergy kit with you at all times.
* Wear a medical alert bracelet to let others know about your food allergy.
* Check the expiration dates on the medicines in your kit, and replace the medicines as needed.

Your child has a food allergy. What else should you think about?

Talk to your child’s teachers and caregivers. They should know how to keep problem foods away from your child. Teach them what to do if your child eats one of these foods by mistake.

If your child has ever had a severe reaction, keep an allergy kit nearby at all times. Some kids carry their kit in a fanny pack. Have your child wear a medical alert bracelet. Teach all caregivers to act quickly. They should:

* Know the signs of a severe reaction.
* Know how to give an epinephrine shot.
* Call 911 right away.

How is a food allergy different from a food intolerance?

Many people think they have a food allergy, but in fact they have a food intolerance. Food intolerance is common. It can cause some of the same symptoms as a mild food allergy, like an upset stomach. But a food intolerance does not cause an allergic reaction. A food intolerance can make you feel bad, but it is not dangerous. A serious food allergy can be dangerous.

If you are not sure which you have, it is a good idea to see your doctor.


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