tropical fish in the news

[h=2]Scientists find secrets of Amazon's piranha-proof fish[/h]
Sapa-AFP | 15 October, 2013 17:31

Visitors to the Blue Zoo Aquarium in Beijing on August 3, 2010 view the South American tropical freshwater fish Arapaima, a living fossil and one of the largest freshwater fishes in the world.
Image by: FREDERIC J. BROWN / AFP


[h=3]An "armoured" fish living in the Amazon has evolved a remarkable multi-layer defence against the voracious piranha, materials scientists reported.[/h][h=3][/h]






[h=2][/h]

Microscopic examination and mechanical testing have revealed the secrets of the arapaima, one of the biggest freshwater fish on the planet.Researchers led by Robert Ritchie at the University of California at Berkeley found its scales have an ultra-tough outer shell, designed to "promote tooth fracture at the point of penetration".The scales also have a corrugated shape, designed to deflect pressure to a thicker, more elastic layer of collagen that lies underneath.The collagen itself is arranged in twisted overlapping layers, called lamellae, that are around 50 nanometres (50 billionths of a metre) thick.They can slide slightly in response to a bite, causing its pressure to be spread over a wider area.The scales "are a prime example of a biological material's evolution for a particular function", says the paper, appearing in the journal Nature Communications."(They are) there to specifically resist the bite of piranhas through multiple levels of defence."Known in Brazil as the "pirarucu," the arapaima is a giant carnivore, growing up to four metres (13 feet) in length and weighing more than 200 kilos.The biggest threat to the fish - Latin name Arapaima gigas - comes from Man. Large numbers began to be taken for food in the 19th century, and the species is now endangered.​

 

:top:

 

Wow!

 

Nice! Pity the pic shows some Gars and a red tailed catfish though... Would have been nice of them to actually show a pic of the Arapaima.

 

There we go!

 

im gonna forward it to the timeslive as well lol

 

Didn't think piranhas would even try to attack an arapaima.

 

I saw a vid on this guy a few days ago on River Mosters.
River Monsters: The Powerful Arapaima : Video : Animal Planet

 

Thanks for that. There is so much we still need to learn about aquatic life.

 

There are videos on youtube where arapaima are attacked and killed by jaguars!

 

ja i been fighting with dstv for not sending me my tv guides then i dont know when all my shows are coming on,when is river monsters?its suppose to be a new season

 

@oscar freak - just for you bud DSTV.COM

Top right, search river monsters. Then if you have PVR - set it to all the dates and record.

Just to add to this - Monday 21st, Channel 121 (Discovery) - 6:25am - 11:40 is a River monsters run of 6 episodes - PVR it

 

lol thanks but dont have a pvr

 

[h=1]Purring monkey and vegetarian piranha among 400 new Amazon species[/h]23 Oct 2013 12:04Guardian Reporter

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Four years of scientific expeditions have uncovered previously unknown animals and plants in the world's largest tropical rainforest.
The Amazon jungle is home to 400 newly discovered species of plant and animal. (AFP)
A purring monkey, a vegetarian piranha and a flame-patterned lizard are among more than 400 new species of animals and plants discovered in the past four years in the Amazon rainforest, say conservationists.
Scientists have discovered 441 new species – all new to science – in hundreds of expeditions between 2010 and 2013. They include 258 plants, 84 fish, 58 amphibians, 22 reptiles, 18 birds and one mammal. This tally does not include discoveries of insects and other invertebrates.
"The more scientists look, the more they find," said Damian Fleming, head of programmes for Brazil and the Amazon at WWF UK, which compiled the list. "With an average of two new species identified every week for the past four years, it's clear that the extraordinary Amazon remains one of the most important centres of global biodiversity."
Among the new species discovered is a "purring" Caqueta titi monkey (Callicebus caquetensis) of the Colombian Amazon, whose babies have an endearing trait: "All of the babies purr like cats," said scientist Thomas Defler, who helped discover the species. "When they feel content they purr towards each other, and the ones we raised would purr to us."
A "warpainted lizard" (Gonatodes timidus) was discovered in the part of the Amazon that extends into Guyana. Despite its extraordinary colouring, this lizard is extremely shy and has a tendency to avoid being seen by humans.
Already endangered
Some species may be lost just as they have been discovered, said scientists. The thumbnail-sized "thimble frog" has been given a Latin name (Allobates amissibilis) meaning "that may be lost", because it thrives in an area of Guyana that could soon be opened up to tourism.
Other species are under threat from development. The strictly herbivorous "vegetarian piranha" (Tometes camunani) inhabits rocky rapids in the Brazilian Amazon where its main source of food, Podostemaceae aquatic herbs, is found. But dam projects and mining activity in Pará state are threatening the health and flow of its river habitat.
Many of the recently discovered plants and animals have restricted ranges and are thought to be endemic to small parts of the Amazon. For example, a new fish species (Apistogramma cinilabra) that has adapted to water with low oxygen levels is unique to one small lake in the Loreto region of Peru and found nowhere else in the world – making it and other species even more vulnerable.
"The richness of the Amazon's forests and freshwater habitats continues to amaze the world," said Fleming. "But these same habitats are under growing threat. The discovery of these new species reaffirms the importance of stepping up commitments to conserve and sustainably manage the unique biodiversity and also the goods and services provided by the rainforests to the people and businesses of the region."
Amazing Amazon
​The Amazon ecosystem is the world's largest tropical rainforest and river system, covering 17.4-million square kilometres shared by Brazil, Bolivia, Peru, Ecuador, Colombia, Venezuela, Guyana, Suriname and French Guiana. It is rich in biodiversity, containing one in 10 of the species known on Earth in 1.4-billion acres of dense forest and 6 600km of winding rivers.
A recent study found that almost 400-billion trees belonging to 16 000 different species grow in the Amazon.
Deforestation, intensive farming, climate change, natural resources extraction and hydropower are among the chief threats to the forest and freshwater ecosystems.
About one-fifth of the Amazon rainforest is already lost and deforestation is taking place at a rate of three football pitches a minute, WWF says.
Brazil has slowed the pace of forest clearance by 80% in the past eight years, but roughly 6 000 square kilometres is still converted to farmland each year.
The Amazon contains between 90-billion tonnes and 140-billion tonnes of carbon and the uncontrolled release of this carbon – through deforestation and land conversion – could accelerate global warming significantly. – © Guardian News and Media 2013