Nouvelle espèce de salamandre ?

Dans le Herpdigest de cette semaine :

Citation :

New Salamander Species Found In Appalachian Foothills Of U.S. (Such A Distinct Amphibian Has Not Been Found In The US For Half A Century)
Matt Walker, BBC, Editor, Earth News

A striking new species of lungless salamander has been found living in a small stream in the Appalachian foothills of the US.

The salamander is so distinct that it's been classified within its own genus, a taxonomic grouping that usually includes a host of related species.

The creature breathes through its skin, and unusually for its kind, males and females have different colouration.

Such a distinct amphibian has not been found in the US for half a century.

The researchers who discovered the salamander describe it in the Journal of Zoology. They have dubbed it the 'patch-nosed' salamander after the yellow patch on the animal's snout.

The tiny animal averages just 25 to 26mm long.

They found so few of the animals that either it is highly secretive, or more likely it survives in such small, isolated numbers that it is already at risk of extinction.
The salamander fauna of the US has been intensively studied for well over a century, so the discovery of such a distinct form was completely unsuspected
Biologist Carlos Camp

"This animal is really a spectacular find," says biologist Carlos Camp of Piedmont College in Demorest, Georgia, who led the team which described the new species.

"It is the first genus of amphibian, indeed of any four-footed vertebrate, discovered in the US in nearly 50 years."

Around the world, there are approximately 500 species of salamander.

Two-thirds of these species are lungless, breathing entirely through their porous, moist skin.

The Appalachian Highlands of the southeastern US is a hot spot for lungless salamander diversity, with species occupying a variety of moist or wet environments including living in streams, underground, among the leaf litter of the forest floor, up cliffs and in trees.

"The salamander fauna of the US, particularly of the southern Appalachians, has been intensively studied for well over a century, so the discovery of such a distinct form was completely unsuspected," says Carlos.

Striking differences

Two graduate students, Bill Peterman of the University of Missouri, Columbia and Joe Milanovich of the University of Georgia, Athens discovered the first example of the species, scientifically named Urspelerpes brucei . They took the animal to Camp for identification.

"When we realised that it was something novel, we contacted a geneticist, Trip Lamb, of East Carolina University, Greenville and a bone specialist, David Wake of the University of California at Berkeley. John Maerz, a professor at the University of Georgia, completed the research team," says Carlos.

The team's investigations revealed just how novel the salamander is.

"The genetic data revealed that this was far more unusual than any of us suspected, which is why we described it in its own genus," says Camp.

But the amphibian also looks strikingly different to other species.

For a start, it has the smallest body size of any salamander in the US. It is also the only lungless salamander in the US whose males have a different colour and pattern than females, a trait more characteristic of birds.

Males have a pair of distinct dark stripes running down the sides of the body and a yellow back. Females lack stripes and are more muted in colour.

Males also have 15 vertebrae, one less than females. Yet while most species of lungless salamander have male and females of differing sizes, those of Urspelerpes brucei are close to being equal in size.

Uniquely for such a small lungless salamander, Urspelerpes brucei has five toes, whereas most other small species have reduced that number to four.

The behaviour and lifestyle of the salamander remain a mystery.

The animal's jaw and teeth structure suggest that it eats small, terrestrial prey such as insects caught using a projectile tongue as some other species of lungless salamander do.

So far, Camp's team have recovered just eight adults, all from within or alongside a single stream. Four were collected hiding under rocks and four in loose leaf litter. Three were females, each carrying eggs.

The last new genus of amphibian living in the US to be described, in 1961, was also a lungless salamander, the Red Hills Salamander of southern Alabama.

Si j'ai bien compris, c'est une petite espèce de salamandre découverte aux USA ?

Par contre, "genus" en anglais se traduit par quoi ? Genre, Famille, ... ?

Genus, c'est genre il me semble.

Espèce c'est: Species

Intéressant, merci Gwalchafed.

Merci Tigri.

Autre nouvelle....

Citation :

5) Bizarre Newt Uses Ribs As Weapons
Matt Walker, Editor, Earth News, BBC 8/21/09
http://news.bbc.co.uk/earth/hi/earth_news/newsid_8212000/8212623.stm
For photos of salamander in action and skeleton

One amphibian has evolved a bizarre and gruesome defence mechanism to protect itself against predators.

When attacked, the Spanish ribbed newt pushes out its ribs until they pierce through its body, exposing a row of bones that act like poisonous barbs.

The newt has to force its bones through its skin every time it is attacked, say scientists who have described the form and function of the barbs in detail.

Yet this bizarre behaviour appears not to cause the newt any ill effects.

The ability of the Spanish ribbed newt to expose its rib bones was first noticed by a natural historian in 1879.

But scientists have now used modern photographic and X-ray imaging techniques to reveal just how the animal does it.

And what they discovered is even more gruesome than they imagined.

When the newt becomes agitated or perceives a threat, it swings its ribs forward, increasing their angle to the spine by up to 50 degrees.

As it does this, the newt keeps the rest of its body still.

"The forward movement of the ribs increases the body size and stretches the skin to the point of piercing it," says zoologist Egon Heiss of the University of Vienna in Austria.

The tips of the newt's ribs then stick outside its body, like exposed spines.

But there is more to the newt's defence, Heiss and his Vienna-based colleagues report in the Journal of Zoology.

"When teased or attacked by a predator, [the newt] secretes a poisonous milky substance onto the body surface. The combination of the poisonous secretion and the ribs as 'stinging' tools is highly effective," says Heiss.

The impact on any predator can be striking, particularly if they try to bite the newt or pick it up using their mouth.

Then the poison in almost injected into the thin skin within the mouth, causing severe pain or possibly death to the attacker.

As well as elucidating the spear-like shape of the ribs, and exactly how the ribs swing forward and protrude, the scientists have demonstrated that the bones must break through the newt's body wall every time the amphibian evokes the defence response.

Initially, it was thought that the ribs may passively emerge through pores, rather than be actively driven through the body wall.

Surprisingly, the newt, which is related to other newts and salamanders, appears to suffer no major ill effects, despite repeatedly puncturing its own body and exposing its rib bones.

"Newts, and amphibians in general, are known to have an extraordinary ability to repair their skin," says Heiss.

"Anyway, if this newt can avoid being eaten in some cases, this surely has a positive influence."

It also seems that the newt is immune to its own poison, which is normally confined to glands in the newt's body.

When the newt wounds itself by exposing its ribs, the poison can seep into its body tissue, again apparently with no ill effects.

Heiss now hopes to investigate which compounds are in the poison.

Ou, c'est connuchez les Pleurodèles walt.