Saturday, October 31, 2009

Bad memories written with lasers

By Victoria Gill
Science reporter, BBC News

Fruit fly head (SPL)
This work in flies will help understand how the human brain makes memories

Laser-controlled flies may be the latest addition to the neuroscientist's tool kit, thanks to a new technique.

Researchers have devised a way to write memories onto the brains of flies, revealing which brain cells are involved in making bad memories.

The researchers said that in flies just 12 brain cells were responsible for what is known as "associative learning".

They describe their findings in the journal Cell.

Associative memories are made when an animal learns to link a cue to a particular outcome. It might for example learn that a certain odour is a sign that a predator is nearby.

"So the appearance of that odour predicts that something bad is going to happen," explained Gero Miesenbock from the University of Oxford, UK, who led this study.

Previous research had already identified that the brain cells or neurons responsible for this type of learning are those that produce dopamine. This is a chemical which acts as a signal that can be transmitted from cell to cell in the brain.

Professor Miesenbock and his team "tapped into these gene regulatory mechanisms" of the neurons - programming them to respond to a laser.

Fly brain (Science)
A laser flash releases a chemical that activates the neurons

They modified the neurons by adding a sort of trigger, or receptor, to each one. This receptor was activated by a chemical called ATP.

"Since there's no ATP floating around in the fly's brain, the [modified] receptors remain closed and the flies behave just like normal flies that don't have the receptor," said Professor Miesenbock.

Now for the laser-activated trickery.

The scientists injected ATP into the flies' brains, in a form that was locked inside a light-sensitive chemical cage.

"[Then] we turned on the laser light and the light sensitive cage fell apart," Professor Miesenbock explained. "The ATP was released and acted only on the cells [with] the receptor."

Memory circuit

The laser flash was paired with an odour, which allowed the scientists to find out if their memory-writing experiment had been successful.

They gave the flies a simple choice between two odours - one of which the flies had been exposed to just before the laser flash.

"[The flies] moved along a narrow chamber and at the midpoint they were presented with an odour on the left and an odour on the right," said Professor Miesenbock.

He knew that the laser had successfully written a bad memory into the fly's brain when the insect avoided the odour that had been paired with the laser flash.

This is a real breakthrough in our understanding of how memories are formed
David Shepherd, neuroscientist

The flies associated the smell with a bad experience, so the laser flash gave the fly a memory of a bad experience that it never actually had.

Simply by looking inside the flies' brains with a microscope, the researchers were able to narrow this memory formation process down to just 12 neurons.

"We labelled the cells .... that were made responsive to light and which ones were not, so by elimination we could narrow it down."

This finding, said Professor Miesenbock, has begun to unravel how animals and humans learn from mistakes and how "error signals" drive animals to adapt their behaviour.

"In the fly we have isolated and manipulated these error signals, so what we can now do is try to understand how these signals are calculated in the brain and how this works mechanistically.

"I have every expectation that the fundamental mechanisms that produce these error signals are the same in the brain of the fly as they are in the brain of the human.

David Shepherd, a neuroscientist from the University of Bangor in North Wales described the study as "a fantastic piece of work".

Professor Shepherd, who was not involved in this study, told BBC News: "We have known for years that flies are capable of sophisticated behaviours such as learning and memory. We have also been able to manipulate gene and cell function in flies.

"This work combines these elements to make a real breakthrough in our understanding of how memories are formed."


Friday, October 30, 2009

Endangered species list released

KOCHI: The Ministry of Environment and Forests has issued a notification under the Biological Diversity Act (2002) and released a revised list of endangered species in Uttarakhand, Uttar Pradesh, Himachal Pradesh and Kerala.

The National Biodiversity Authority has issued alerts to protect 13 animal species and 26 plant species threatened with extinction in Kerala, the state with the most number of threatened species in the list.

Uttarakhand comes next, with 16 plant species and 15 animal species, while Himachal Pradesh has eight plant species and Uttar Pradesh has just one plant species threatened with extinction.

As per the conditions, no plant or animal species shall be collected live or dead by any person, except for scientific research, by herbariums and museums of scientific and academic institutions and for scientific investigation only. This can be done only with a State Biodiversity Board approval.

The notification, issued by MoEF joint secretary A K Goyal, has asked the State Biodiversity Board to conduct awareness programmes and provide educational material on notified species to Forest Department personnel, biodiversity management committees, ecotourism programmes, forest dwellers and tribals.

The 13 threatened species in Kerala include Fruit bats, the Malabar Large- Spotted Civet, Blue Whales, Sea Cows, Tigers, the Indian Vulture, Leatherback Sea Turtles, Hawkbill Sea Turtles, Hawkbill Sea Turtles, Murthi’s Frog, the Toad-skinned Frog, Green Saw Fishes and the Philautus Chalaziodes.

The 26 plant species named include Syzygium Palghatense, Syzygium Periyarensis (Wild Jamuns), Vanda Thwaitesii (Nyarapazham) and Janakia aryapathra (Aryalpathram).


Thursday, October 29, 2009

Family comes first, among plants too


Caring and sharing within the family are traits we associate with humans and animals. But a startling new study has found that for plants too, “blood is thicker than water”.

They cannot speak, move, see or hear, but plants apparently recognize family and respect their space, says the study. It was conducted by scientist Harsh Bais and his colleagues at the University of Delaware. “At least 3,000 plants were researched and it took us three years,” Bais tells Eureka via email. He says that Arabidopsis thaliana, a member of the mustard family and widely used as a model organism in plant biology, behaves nicely to ‘siblings’ – i.e. plants grown from seeds from the same ‘mother’. Interestingly, it is intensely competitive with strangers.

Fascinating and unbelievable though this may be, talk of plants and their ‘siblings’ is not new. In 2007, a team of Canadian researchers showed that plants can indeed identify ‘siblings’. But Bais and his team went a step further by discovering how a plant recognizes its ‘brother’ or ‘sister’, namely by root secretions. When the plant sensed unfamiliar root secretions, it began competing by growing more roots in order to absorb more of the soil’s mineral nutrients and water. But with ‘siblings’, they threw out fewer roots. When Bais treated
a plant to a chemical that blocked the secretions, it seemed to lose its discriminatory sense. Clearly, there is something in these secretions that tells a plant whether it is related to others around it.

Strangers planted next to each other are often shorter, it noted, because so much of their energy is concentrated on root growth. “It’s possible that when kin are grown together, they may balance their nutrient uptake,” says Bais.

Harsh Bais with a PhD student at the University of Delaware


Wednesday, October 28, 2009

Secrets of frog killer laid bare

By Richard Black
Environment correspondent, BBC News website

Signs of infection

Scientists have unravelled the mechanism by which the fungal disease chytridiomycosis kills its victims.

The fungus is steadily spreading through populations of frogs and other amphibians worldwide, and has sent some species extinct in just a few years.

Researchers now report in the journal Science that the fungus kills by changing the animals' electrolyte balance, resulting in cardiac arrest.

The finding is described as a "key step" in understanding the epidemic.

Karen Lips, one of the world authorities on the spread of chytridiomycosis, said the research was "compelling".

This is lethal across a broad range of hosts, so it's really important to look at what's happening in other amphibians
Jamie Voyles, James Cook University

"They've done an incredible amount of work, been very thorough, and I don't think anybody will have problems with this.

"We suspected something like this all along, but it's great to know this is in fact what is happening," the University of Maryland professor told BBC News.

Skin deep

Amphibian skin plays several roles in the animals' life.

Most species can breathe through it, and it is also used as a membrane through which electrolytes such as sodium and potassium are exchanged with the outside world.

A world of amphibians

The mainly Australian research group took skin samples from healthy and diseased green tree frogs, and found that these compounds passed through the skin much less readily when chytrid was present.

Samples of blood and urine from infected frogs showed much lower sodium and potassium concentrations than in healthy animals - potassium was down by half.

In other animals including humans, this kind of disturbance is known to be capable of causing cardiac arrest.

The scientists also took electrocardiogram recordings of the frogs' hearts in the hours before death; and found changes to the rhythm culminating in arrest.

Drugs that restore electrolyte balance brought the animals a few hours or days of better health, some showing enough vigour to climb out of their bowls of water; but all died in the end.

Grail quest

Lead scientist Jamie Voyles, from James Cook University in Townsville, said the next step was to look for the same phenomenon in other species.

"This is lethal across a broad range of hosts, whether terrestrial or aquatic, so it's really important to look at what's happening in other susceptible amphibians," she said.

Dead Atelopus frog
Ways to stop chytrid in the wild are the "holy grail" for researchers

Another step will be to examine how the chytrid fungus (Batrachochytrium dendrobatidis - Bd) impairs electrolyte transfer.

"What this work doesn't tell us is the mechanism by which chytrid causes this problem with sodium," said Matthew Fisher from Imperial College London.

"It could be that Bd is excreting a toxin, or it could be causing cell damage. This causative action is actually the 'holy grail' - so that's another obvious next step."

The finding is unlikely to plot an immediate route to ways of preventing or treating or curing the disease in the wild.

Curing infected amphibians in captivity is straightforward using antifungal chemicals; but currently there is no way to tackle it outside.

Various research teams are exploring the potential of bacteria that occur naturally on the skin of some amphibians, and may play a protective role.

Understanding the genetics of how Bd disrupts electrolyte balance might lead to more precise identification of protective bacteria, suggested Professor Lips, and so eventually play a role in curbing the epidemic.


Tuesday, October 27, 2009

Rare species of mangrove tree found along Sindhudurg coast

Kalyani Sardesai | TNN

Pune: City-based amateur botanist and photographer Shrikant Ingalhalikar and Narendra Page, a doctorate student of forest ecology from the Indian Institute of Science, Bangalore, recently came across the Sundari (Heritiera littoralis), a rare mangrove tree, along the Sindhudurg coast. This is the first such recording of the tree in Maharashtra and probably on the West coast, they said.

The tree is also known as the ‘looking-glass tree’, probably because the leaves are silver-coated. It is found in large numbers in the Sundarbans in Bengal and to a lesser degree at Bhitarkanika at the delta of the Mahanadi river in Orissa.

“This is an important find, and the forest department must be made aware of this rare natural resource,” said Ingalhalikar. “This is the first record in Maharashtra and may be the only
record of a living specimen on the west coast. A century ago, a specimen of this tree was reported on the Kali river at Karwar in north Karnataka. There is also an old report from Kerala. In recent times the tree was believed to be extinct on the west coast.”

The duo say they have also found four other species of rare mangrove trees in the adjoining areas of Sindhudurg. “The Sindhudurg habitat also supports Xylocarpus granatum, Cynometra iripa, Dolichandrone spathacea and Rhizophora apiculata. These species exist in small, scattered populations in Goa and Karnataka as well. This unusual diversity makes the coastal habitat of Sindhudurg ecologically sensitive as it is very much the ‘hot spot’ for rare mangrove species,” Ingalhalikar said.

“Besides protecting the mangrove forests, it is necessary to cultivate such rare species for preservation of biodiversity,” he stressed.

A Sundari tree (Heritiera littoralis)


'Snakeman' Ranade was city's best rescuer

Mumbai: On Sunday, Mumbai lost its best and most experienced snake rescuer. For Kedar Bhide, 33, who runs the Reptile Rescue and Study Centre (RRSC), Sunil Ranade's death is a personal loss.

Thirty-seven-year-old Ranade was credited with rescuing over 15,000 snakes in the past 15 years. Ironically, it is this passion for the venomous reptiles that cost him dearly -- he died after being bitten by a Vinocellate Cobra.

"He was passionate to the point of being obsessisive about these reptiles," said Bhide, who had known him for over ten years.

Ranade was working as an animal inspector with the Society for Prevention of Cruelty to Animals (SPCA), Parel for the past five years. "But it was more than a job to him. He did not have scientific education. It was sheer passion that drove him," said Bhide, who, a day later, cannot help but rue the fact that Ranade's death could have been prevented.

"Had someone, who knew first aid for snake bite, been nearby, he could have been saved," he said.

The worst part is, Ranade had four vials of anti venom in his house -- all snake rescuers are told to keepthe anti- venom handy, due to the dangerous nature of their job.

About 50 to 60% of the time, the bite of the cobra is what is termed a 'dry bite', where the venom doesn't come out of its teeth. "Maybe, Sunil assumed it must have been a dry bite. He was also quite afraid of hospitals and injections, so he may have waited for the symptoms to come up," he added.

"Mumbai has many snake catchers, but not all of them are trained. And as far as anti-venom is concerned, all government hospitals have an emergency stock," said Bhide, who, with a group of snake rescuers, now plans to start a fund to help Ranade's two daughters.

Mumbai's top snake-man falls to cobra attack

Mumbai's well-known snake-catcher and conservationist Sunil S. Ranade, credited with rescuing over 15,000 snakes in the past 15 years, died after he was bitten by a cobra Sunday, an official said.

Ranade, 37, was rescuing snakes, reptiles and other wild creatures since over two decades. He was working as animal inspector with the 136-year old Society for Prevention of Cruelty to Animals, in its Parel hospital, according to Col. J. C. Khanna, the SPCA secretary.

"Yesterday (Saturday), he had rescued a cobra from somewhere and had kept it in a container in his home in the hospital premises. Around 2.30 a.m., he had gone to feed the creature when it suddenly attacked him. It's a truly an unfortunate incident." Khanna, a member of Animal Welfare Board of India, told IANS.

At the time of the incident, his wife with their two daughters - aged 10 and 3 - had gone to his father-in-law's home in Malad suburb.

Hearing a commotion from Ranade's quarters, some neighbours and other staffers rushed there to see him lying semi-conscious and writhing in pain.

They summoned an ambulance and shifted him to a nearby hospital where he succumbed after a few minutes.

"He was an expert on reptiles, especially snakes. He even had emergency vaccines and a pump to remove poison at home. Despite all precautions, we are sad that he met his end in this manner," Khanna said.

The incident is akin to the death of the famous Australian conservationist Steve Irwin in September 2006 when he was shooting for a Discovery Channel programme undersea when a poisonous stingray (fish) attacked him. Steve died later.

Khanna assured Ranade's family that since he was the sole breadwinner, the organisation would provide all necessary assistance to his surviving family members.

Ranade was the first person Mumbaikars would contact in case of any encounters with reptiles or other wild creatures in and around the city.

During the great Mumbai floods of July 26, 2005, Ranade had rescued nearly 100 snakes from different parts of the city and after treating them, released them in the Sanjay Gandhi National Park (SGNP).


Monday, October 26, 2009

वाइल्ड लाइफ तिच्या 'डोळ्यां'तून

अंड आणि त्याला पडलेलं छोटसं भोक आणि त्यातून कोणीतरी अन्नरस शोषून घेतल्याची फ्रेम... लहान मुलांचं होणारं शोषण यावर काढलेला हा फोटो पाहिल्यावर मन विचार करायला लागतं..

काळसर तपकिरी रंगाची विंचवाची मादी आणि तिच्या पाठीवर असलेली छोटसं पिल्लू... आक्रमकतेने दंश करण्यासाठी तयार असलेला हिरवा साप... निसर्गातल्या विविध वन्य प्राण्यांना आपल्या कॅमेरारूपी डोळ्यांनी टिपलंय ठाण्यातल्या तरुण वाइल्डलाइफ फोटोग्राफर वेदवती पडवळने.

नुकताच अमरावतीच्या 'नेचर कन्झरव्हेशन सोसायटी', 'मेळघाट टायगर रिर्झव्ह', झूओलॉजी विभाग आणि एसजीबी, अमरावती युनिर्व्हसिटी यांच्यावतीने घेण्यात आलेल्या फोटोग्राफी स्पधेर्मध्ये वेदवतीच्या 'स्कॉपिर्अन विथ बेबीज' या फोटोला प्रथम पारितोषिकाने सन्मानित करण्यात आलंय. तसंच डिपार्टमेण्ट ऑफ सायन्स अॅण्ड टेक्नॉलजीने आयोजित केलेल्या राष्ट्रीय स्तरावरच्या फोटोग्राफी स्पधेर्मध्ये 'कॉन्सेप्टच्युअल' विषयातल्या 'चाइल्ड अॅब्यूज' या छायाचित्राला दुसऱ्या क्रमांकाचं पारितोषिक जाहीर झालं आहे.

युरोप खंडामध्ये २४ मे 'नॅशनल पार्क डे' म्हणून साजरा केला जातो. त्यानिमित्ताने तिथे जगभरातल्या नामांकित फोटोग्राफर्सची निवडक छायाचित्र प्रदशिर्त केली जातात. गेली दोन वर्षं वेदवतीचे फोटो या आंतरराष्ट्रीय प्रदर्शनात प्रदशिर्त होत आहेत. 'फोटोग्राफी सोसायटी ऑफ इंडिया'च्या बाराव्या आंतरराष्ट्रीय फोटोग्राफी प्रदर्शनात तिचे फोटो रसिकांच्या पसंतीस उतरले होते. गेल्या वषीर् केरळमध्ये 'बटरफ्लाय आर्ट फाऊंडेशन'ने भरवलेल्या प्रदर्शनात तिला 'सटिर्फिकेट ऑफ एक्सलन्स'ने सन्मानित केलं होतं. ४९व्या महाराष्ट्र राज्य कला प्रदर्शनातही तिची छायाचित्रांना रसिकांच्या मनाचा ठाव घेतला.

वेदवती जे. जे. इन्स्टिट्यूट ऑफ आर्टच्या कमशिर्यल आर्ट शाखेची पदवीधर. फोटोग्राफी हा तिचा खास विषय आणि तिची पॅशन. गेली पाच वर्षं सातत्याने ती फोटोग्राफी करत आहे. त्यातही नेचर आणि वाइल्डलाइफ फोटोग्राफी हा तिचा आवडता विषय. ठाण्यातले वाइल्डलाइफ फोटोग्राफर युवराज गुर्जर यांच्यासोबत ती साताऱ्याजवळच्या कास पठारावर गेली होती. तिथे तिथला निसर्ग आणि तिथल्या अद्भुत वन्यजीवनाशी, सजीवांशी परिचय झाला. जंगलातली जैवविविधता, निसर्गाचे विभ्रम यांनी तिच्या मनाला भुरळ घातली आणि तिचा वाइल्डलाइफ फोटोग्राफीचा प्रवास सुरू झाला. त्यानंतर तिने मागे वळून पाहिलेच नाही. भारतातल्या गोरूमारा, गीर, वेलावदार, जिम कॉबेर्ट, कान्हा, बांधवगड, भरतपूर, रणथंबोर, बोंडला अशा अनेक जंगलांत आणि अभयारण्यांमध्ये जाऊन तिने आपली 'पॅशन' जपली. याकाळात तिने वन्यप्राण्याचं जीवन आपल्या कॅमेऱ्याने अत्यंत कल्पकतेने टिपलं. त्यातही तिने टिपलेले वाघांचे फोटो पाहण्यासारखेच आहेत. वाघांचे फोटो काढणं ही तिची खास आवड असल्याचं ती सांगते.

आपलं वेड जोपासण्यासाठी ती दर रविवारी येऊरच्या जंगलामध्ये फिरायला जाते. तिथेच तिला एक नवी वाट मिळाली ती 'मायक्रो' फोटोग्राफीची. यामध्येही तिने आपलं कसब दाखवलं आहे. कमी वयात वेदवतीने आपल्या करिअरचा खूप पुढचा टप्पा गाठला असून तिने व्यवसाय म्हणूनही हेच क्षेत्र निवडलं आहे. ठाण्यात तिचा स्वत:चा स्टुडिओही आहे.

तिच्या या पॅशनबद्दल ती सांगते, जंगलातल्या खाचखळग्यांच्या आणि धुळीच्या रस्त्यांवरून फिरणं, जीपमधून तासन्तास भटकणं मला आवडतं. निसर्गाची अद्भुत रूपं पाहिल्यावर मन चकित होतं आणि तेच मी माझ्या कॅमेरात पकडण्याचा प्रयत्न करते. जंगलामध्ये जीपमधून १५-२० फुटांवरच्या वाघाचं किंवा प्राण्याचा फोटो काढण्यासाठी मानसिक संतुलन पक्कं असावं लागतं. त्यासाठी मेहनत आणि सरावाची गरज असते.

- प्रकाश पिटकर

Sunday, October 25, 2009

'Giant' orb web spider discovered

Orb-weaviing spider Nephila inaurata
Orb-weaving spiders can spin webs of up to 1m (3ft 3in) in diameter

A new and rare species of "giant" orb web spider has been discovered in Africa and Madagascar.

In the journal Plos One, researchers describe Nephila komaci as the largest web spinning spider known to science.

Only the females of this groups of species are giants, with a leg span of up to 12cm (4.7in); the male spiders are tiny by comparison.

Scientists say the female spiders are capable of spinning webs that reach up to 1m (3ft 3in) in diameter.

Orb-weaving spiders are a widespread group which take their name from the round webs they typically spin.

Diagram of orb-weaving spider body Nephila komaci
The few preserved female specimens had bodies almost 4cm (1.5in) long

The new spider was identified by Matjaz Kuntner, a biologist from the Slovenian Academy of Sciences and Arts, and his colleague Jonathan Coddington, from the Smithsonian Institution's National Museum of Natural History in Washington DC.

Dr Kuntner told BBC News that the discovery was "very unusual" because Nephila spiders were so well-studied and so large.

But this species is so elusive that even Dr Kuntner has not seen one live. He was able to identify the species from a specimen he first examined in 2000.

The giant female was in a collection belonging to the Plant Protection Research Institute in Pretoria, South Africa.

"It did not match any described species," said Dr Kuntner.

In his search through more than 2,500 samples from 37 museums, no further specimens turned up and he assumed the spider must be extinct.

But when a colleague in South Africa found three more of the spiders, it became apparent that they belonged to this same new species.

Nephila komaci
Male Nephila spiders look tiny in comparison to "giant" females

The discovery will enable scientists to study the evolution of the dramatic size difference between male and female Nephila spiders.

Dr Kuntner explained that the widely accepted theory was that evolutionary pressure was causing female "gigantism", with the females increasing in size in order to produce larger numbers of offspring.

He and his colleague, Jonathan Coddington, from the Smithsonian Institution's National Museum of Natural History in Washington DC, fear the rare spider might be endangered.

"Its range is restricted and all known localities lie within two endangered biodiversity hotspots: Maputaland and Madagascar," said Dr Coddington.

Dr Kuntner named the species in honour of his best friend and fellow scientist Andrej Komac, who recently died in an accident.

Friday, October 23, 2009

'Veggie' spider shuns meat diet

By Rebecca Morelle
Science reporter, BBC News

The mainly vegetarian spider was caught on camera

A spider that dines almost exclusively on plants has been described by scientists.

It is the first-known predominantly vegetarian spider; all of the other known 40,000 spider species are thought to be mainly carnivorous.

Bagheera kiplingi, which is found in Central America and Mexico, bucks the meat-eating trend by feasting on acacia plants.

The research is published in the journal Current Biology.

The herbivorous spider was filmed on high-definition camera.

Running the gauntlet

The jumping arachnid, which is 5-6mm long, has developed a taste for the tips of the acacia plants - known as Beltian bodies - which are packed full of protein.

This is the only spider we know that deliberately only goes after plants.
Professor Robert Curry

But to reach this leafy fare, the spider has to evade the attention of ants, which live in the hollow spines of the tree.

The ants and acacia trees have co-evolved to form a mutually beneficial relationship: the aggressive ants protect the trees from predators, swarming to attack any invaders; and in return for acting as bodyguards, the ants get to gorge on the acacias' Beltian bodies themselves.

But the crafty Bagheera kiplingi has found a way to exploit this symbiotic relationship.

Bagheera kiplingi spider and ant (R. Curry)
The spiders have to dodge ants to get to the leaf tips

One of the study's authors, Professor Robert Curry, from Villanova University, Pennsylvania, told BBC News: "The spiders basically dodge the ants.

"The spiders live on the plants - but way out on the tips of the old leaves, where the ants don't spend a lot of time, because there isn't any food on those leaves."

But when they get hungry, the spiders head to the newer leaves, and get ready to run the ant gauntlet.

Professor Curry said: "And they wait for an opening - they watch the ants move around, and they watch to see that there are not any ants in the local area that they are going after.

"And then they zip in and grab one of these Beltian bodies and then clip it off, hold it in their mouths and run away.

"And then they retreat to one of the undefended parts of the plant to eat it."

Like other species of jumping spider, Bagheera kiplingi has keen eyesight, is especially fast and agile and is thought to have good cognitive skills, which allows it to "hunt" down this plant food.

Fierce competition

The spider's herbivorous diet was first discovered in Costa Rica in 2001 by Eric Olsen from Brandeis University, and was then independently observed again in 2007 by Christopher Meehan, at that time an undergraduate student at Villanova University.

Competition in the tropics is pretty fierce so there are always advantages to do what someone else isn't already doing
Professor Curry

The team then collaborated to describe the spider for the first time in this Current Biology paper.

Professor Curry said he was extremely surprised when he found out about its unusual behaviour.

He said: "This is the only spider we know that deliberately only goes after plants."

While some spiders will occasionally supplement their diet with a little nectar or pollen, Bagheera kiplingi's diet is almost completely vegetarian - although occasionally topped up with a little ant larvae at times.

Professor Curry said there were numerous reasons why this spider might have turned away from meaty meals.

He said: "Competition in the tropics is pretty fierce so there are always advantages to doing what someone else isn't already doing.

"They are jumping spiders, so they don't build a web to catch food, so they have to catch their prey through pursuit. And the Beltian bodies are not moving - they are stuck - so it is a very predictable food supply."

Acacias also produce leaves throughout the year - even through the dry season - which would make them attractive.

And Professor Curry added: "Because the plants are protected by ants, they have none of their own chemical defenses that other plants do."


Also Check : First plant-eating spider discovered

Thursday, October 22, 2009

Winged beauties aflutter

A novel project mooted by the forest department in the nineties to set up a butterfly park at Bhironda in Valpoi and another one in South Goa may not have seen the light of day, but lovers of these multi-hued insects continue to be dazzled by these vibrant creatures and a group of them strongly advocate a better conservation effort to save them.

Recently a group of 33 professionals and members of "Butterfly India" traipsed around the wilds of Goa chasing and documenting butterflies for five days as part of their annual meeting. The group included nature photographers, zoologists, an entomologist, wildlife enthusiasts and butterfly lovers, who trekked areas of Bondla, Bhagwan Mahavir National Park, Bhagwan Mahavir Wildlife Sanctuary and Neturlim Wildlife Sanctuary and returned impressed by the rich biodiversity.

Says entomologist Amol Patwardhan of Thane, "Goa is an ideal place for butterfly conservation and the hinterland has a pretty good green cover." Patwardhan also backed the forest department's plan to set up a butterfly park, stating it would add to Goa's tourism profile. "Being a tourist destination, it can be an additional attraction and even a money spinner, as climatic and other conditions are suitable for this type of conservation effort," he said.

Agrees Parag Rangnekar, who has published a book on butterflies, "It can add to the state's tourism attractions because very few states have promoted butterflies. Actually any place is okay, but it should be an undisturbed area with space to plant the right kind of host and food plants."

Patwardhan whose job includes classifying insects also advised caution about the location and methodology to be adopted in pursuing the proposal. "Care should be taken to avoid ecological problems and the site should be away from mining areas. Also, conservation has to be scientific. There should be plants suitable for caterpillars to feed on and others of the flowering variety (nectar-bearing) for adult butterflies," said Patwardhan. Butterflies have their own choice of host plants. Agreed Rangnekar, "Butterflies have to be cared for like babies," he said.

However, deputy conservator of forest (wildlife and eco tourism) Debendra Dalai said that he was not aware of any proposal for setting up a butterfly park. "A suggestion for setting up a butterfly park at Bondla was made during discussions recently on a master plan for Bondla zoo. It has already been finalized and cannot be modified now," he said. "However, it cannot be thought of as a separate project. It doesn't require huge infrastructure, but mainly the specific requirement of host plants for butterflies and there are hardly any hassles in implementing it."

Concurring with Patwardhan about the need for a conservation programme for butterflies, Rangnekar said NGOs should also extend their support, as the main danger lies in the possible destruction of habitats. Habitat-specific species of butterflies face the worst peril. "Take the case of the Malabar Tree Nymph. It can be found only in certain areas of Goa's western ghats. If the area in which they can be found is destroyed or their habitat is in danger, they may be wiped off," says Rangnekar.

Several species of butterflies may not be endemic, but there are a few habitat-specific species. "The danger is that people may not realize that if their habitat is destroyed, butterflies may be affected, but climatic conditions and host plants are interconnected requirements for their subsistence," Ragnekar explained.

As far as the location is concerned, the state is strategically poised in one of the global biodiversity hotspots of the western ghats. "Goa is at the confluence of northern and southern part of the western ghats' range which spans from Tamil Nadu to Gujarat. Some species of butterflies found here are also reported in southern states, but not in Maharashtra, and hence conservation to preserve these is important." says Rangnekar. For instance, the Malabar Tree Nymph can be found aplenty in the Brahma Karmali area of Satari. "If the area is destroyed, then nature and butterflies will lose out," he added.

A Ponda-based NGO has set up a small butterfly conservatory at Pisgal. "This is an appreciable initiative, but with better support, both technical and financial, a larger facility with an interpretation centre could be set up," Ragnekar added. According to Omkar Dharwadkar, studies on Goa's fauna may be few, but butterflies are "fairly well documented". The Zoological Survey of India, western regional station, Pune in its fauna series has listed 251 species, while scientist Harish Gaonkar's compilation on the entire western ghats has a few more. Manoj Borkar and Neelam Komarpant have documented 90-odd species at Bondla, while Rangnekar has photo-documented around 140 species in the entire state.

The latest exercise in chasing butterflies yielded more success as three more species not earlier reported were found. "We found the Black-vein sergeant (Athyma ranga moore), White-banded awl (Hasora taminatus Hübner) and Coon (Psolos fuligo Mabille)," says Rangnekar. Thus, the total number of species reported in Goa has gone up to 258.

Nature lovers feel that more species can be identified and documented, but it needs a little extra effort. "By merely photographing them, one cannot identify them. They have to be collected and put under the microscope for scientific purposes and determining their seasonality and flight pattern. It is the need of the hour," says Rangnekar.

I Smell An Invasive Rat

Genetic tests pin down origins of island-hopping rodents
RatAfter managers try to eliminate an invasive species from an ecosystem, the pests can sometimes turn up again. But are the animals survivors of the eradication or new invaders from a different region?
The answer is important for pest managers because it determines whether the original eradication attempt worked, researchers say in Biological Invasions. If the animals are survivors, the strategy may need to be changed – a potentially costly process. On the other hand, a reinvasion might mean that security needs to be strengthened.
The team studied one scenario at Pearl Island, New Zealand, an area that was invaded by three rat species. After managers attempted to stamp out the pests in 2005, 13 rats were found in 2006, and one species spread across the island by 2007. To find out where the rodents had come from, the researchers analyzed the DNA of rats from Pearl Island, both before and after eradication, as well as from neighboring Stewart Island.
The newly discovered rats bore the genetic traits of the Stewart Island population, the team concluded. So while the eradication succeeded, rats appear to be swimming to Pearl Island faster than expected. The researchers say that similar tests could be used to evaluate other eradication campaigns, as long as managers collect samples of the species before removal. – Roberta Kwok
Source: Russell, J., Miller, S., Harper, G., MacInnes, H., Wylie, M., & Fewster, R. (2009). Survivors or reinvaders? Using genetic assignment to identify invasive pests following eradication Biological Invasions DOI: 10.1007/s10530-009-9586-1

Wednesday, October 21, 2009

New Research Suggests Conservation Biologists are Setting Minimum Population Size Targets Too Low to Prevent Extinction

A new study by University of Adelaide and Macquarie University (Australia) scientists has shown that populations of endangered species are unlikely to persist in the face of global climate change and habitat loss unless they number around 5,000 mature individuals or more.

The findings have been published in a paper entitled 'Pragmatic population viability targets in a rapidly changing world' in the journal Biological Conservation.

A long-standing idea in species restoration programs is the '50/500' rule. This states that at least 50 adults are required to avoid the damaging effects of inbreeding, and 500 to avoid extinctions due to the inability to evolve to cope with environmental change.

For this study, researchers investigated existing data regarding the minimum population size requirements for species based on empirical and theoretical estimates made over the past few decades. This literature was found to indicate that thousands, rather than hundreds, of individuals are required for a population to have an acceptable probability of riding out environmental fluctuation and catastrophic events, and ensuring the continuation of evolutionary processes.

"Often, [conservation biologists] aim to maintain tens or hundreds of individuals, when thousands are actually needed," says lead author Dr. Lochran Traill, from the University of Adelaide's Environment Institute. “Our review found that populations smaller than about 5,000 had unacceptably high extinction rates. This suggests that many targets for conservation recovery are simply too small to do much good in the long run."
"Our research suggests that the 50/500 rule is at least an order of magnitude too small to effectively stave off extinction," says Dr. Traill. "This does not necessarily imply that populations smaller than 5,000 are doomed. But it does highlight the challenge that small populations face in adapting to a rapidly changing world."

Team member Professor Richard Frankham, from Macquarie University's Department of Biological Sciences, says: "Genetic diversity within populations allows them to evolve to cope with environmental change, and genetic loss equates to fragility in the face of such changes."

Conservation biologists worldwide are battling to prevent mass extinctions in the face of a growing human population and its associated impact on the planet.

“We shouldn't necessarily give up on critically endangered species numbering a few hundred of individuals in the wild," says Dr Traill. "Acceptance that more needs to be done if we are to stop 'managing for extinction' should force decision makers to be more explicit about what they are aiming for, and what they are willing to trade off, when allocating conservation funds."

Other researchers in the study are Associate Professor Corey Bradshaw and Professor Barry Brook, both from the University of Adelaide's Environment Institute. Information from the University of Adelaide and EurekAlert.

Story & Research Paper

Tuesday, October 20, 2009

Common pills, plastics making male fish lay eggs

WASHINGTON: Plastics, pesticides and even common prescription drugs are releasing synthetic and natural hormones into rivers and streams, which is leading to unintended consequences on wildlife, causing some male fish to become feminised and lay eggs.

In a recent report, it was found that one third of small mouth bass were feminised in nine major U.S. river basins, and almost all of the rivers and streams tested in the United States contained some hormonally active chemicals.

And now in a conference, the researchers are focusing on the long-term consequences of hormones and endocrine disruptors in the environment.

"It is one of the hottest topics in environmental biology right now. The biological activity of these compounds both in terms of other species and, potentially, ourselves is something that scientists are becoming more and more aware of through research," said Dr. John McLachlan, director of the Tulane/Xavier Center for Bioenvironmental Research, which is hosting the conference.

Now scientists are looking at the proliferation of prescription drugs like antidepressants, contraceptives and other medications that are ending up in waste water after being taken by people.

Most municipal water treatment systems don't have the ability to neutralize pharmaceutical compounds in waste water so they end up in rivers and streams, said McLachlan.

"They all end up in different places in the environment. What do they do to the wildlife that absorb them and, more importantly, what do they do to our water sources?" he says.

A recent study found feminised male fish in almost a third of 111 sampling sites in nine major U.S. river basins and scientists are studying whether endocrine disruptors are responsible.

Tyron Hayes, a leading expert in inter sexed amphibians, will be speaking at the conference about his research on the effects of endocrine disruptors on wildlife.

The conference also discusses how hormones affect the body and endocrine system and how they may play a role in diseases like breast cancer.

The findings will be discussed in the Tenth International Symposium on Environment and Hormones (E.hormone 2009).


Friday, October 16, 2009

Scientists trying to identify ’sanjivani’ herb

LUCKNOW - The ’sanjivani’ may not be just myth. Scientists are now busy trying to identify the magical herb, which according to the Indian epic Ramayana brought back to life Lord Ram’s dying brother Lakshman.

Having found a few Himalayan herbs that match the description of the sanjivani, a team of five scientists at the National Botanical Research Institute (NBRI) here is working on identifying the properties of each of these.

“We are engaged in a genetic analysis of these herbs to zero in on what we are looking for in a true sanjivani herb,” team leader P.N. Khare told IANS.

What has made the task difficult is the lookalike features of several different herbs found at high altitudes in the Himalayas from where monkey god Hanuman is understood to have fetched the herb to save the life of Lakshman who was injured in battle.

One of the herbs which appeared to be very close to the sanjivani, as identified in the Ramayana, has a very special property: no matter how dead it might appear, on being kept under dry conditions, it revives within minutes of being exposed to moisture.

“In fact, we are looking into this unique feature, which is quite rare and appears to be the key factor for its hidden rejuvenating strength,” Khare said.

While NBRI scientists are engaged in the project, ayurvedic researchers at yoga guru Baba Ramdev’s Pantajali Ashram in Rishikesh claim to have already found the right herb.

“We do not dispute their claim, but as far as we are concerned we would not like to make any claim without substantiating it with laboratory proof,” Khare said.


Thursday, October 15, 2009

Butterflies soaring higher due to climate change in Himalayas region

KATHMANDU, April 9 (Xinhua) -- Climate change comes home to roost. A research, based on Apollo butterfly and Pika hare, the harbingers of global warming, conducted by the World Wildlife Fund (WWF) in Nepal's Langtang region of the Himalayas indicate a disturbing trend.

According to Thursday's THT Online report, both the insect and mammal have migrated up to 500 meters in the upper reaches in the last 15 years or so due to the adverse impact of climate change.

"Usually Apollo butterflies are found at 3,000 meters above sea level. Over the years, it has moved 500 meters above. While, Pika has relocated 100 meters higher," Bhaiya Khanal of Natural History Museum told the website.

Khanal, an expert on butterflies, was a part of the WWF team that conducted the research.

"We can find more evidence of climate changes in the Himalayan region if we conduct an extensive survey. It has been observed that some species of butterfly like Pancy and Crow, which are usually found in the Terai (plain), are now being sighted in the Valley these days," he explained.

There has been a discernible shift in the life cycle of butterflies as well.

Earlier, it would be visible from April to October-November. Now, species like Pieris, Urema and Papillion are found in the wild in March. While, other varieties are making its presence felt in Koshi and Bardiya conservation areas in December. Pieris, which usually lives in 1,800 meters, has moved up to 2,200 meters. Of the 14 families, belonging to 650 species, 11 are found in Nepal.

At a conservative estimate, the Nepali capital Kathmandu Valley and its fringes are home to around 369 species of butterfly.

Dr Dinesh Raj Bhuju, chief of Science and Technology at Nepal Academy of Science and Technology, attributed the drastic changes to global warming.

There has been an annual rise in mercury by .06 degree Celsius. Rampant deforestation, destruction of habitat, haphazard industrialization and unscientific use of pesticides and insecticides have gradually sounded a death knell for the rich and diverse fauna in Nepal, he said.


Wednesday, October 14, 2009

First plant-eating spider discovered

Plant-eating-spiderx-large A plant-eating spider? Investigators report the Central American jumping spider feeds on acacia shrubs, making it the first known herbivore among spiders.

In the journal Current Biology, the team led by Christopher Meehan of Villanova University, details how the jumping spider, Bagheera kiplingi, outsmarts ants that live and protect acacia shrubs to prey on the plant's tasty leaf tips. "By circumventing acacia-ant defenses and intercepting ant-acacia rewards, B. kiplingi is the first spider reported to feed primarily and deliberately on plants," says the study.

At sites in both Mexico and Costa Rica, the team reports the spiders feed mainly on the leaf tips used as homes by the ants, which regularly fend off other bugs and plants encroaching on the shrubs, as well as plant nectar. "These spiders occur almost exclusively on ant-occupied acacias, where they breed year-round and generally build their nests at the distal (far) tips of older leaves that have low rates of ant patrol," says the study.

Jumping spider's skills at hunting prey may have enabled the ancestors of the plant-eating species to evolve into ant-evading salad bar fans. "Given that no other spider is known to feed on vegetation, the digestive physiology of B. kiplingi may be specialized to process such a fibrous, nitrogen-poor material. Year-round availability of ant-plant food, combined with indirect defensive benefits possibly conferred by the acacia-ants, may also help explain how the spider’s carnivorous ancestor transitioned to herbivory," the study concludes.

By Dan Vergano
Photo: An adult female Bagheera kiplingi spider defends her nest against acacia-ant worker. (R. L. Curry)


Tuesday, October 6, 2009

Giant fish 'verges on extinction'

By Jody Bourton
Earth News reporter

Chinese paddlefish (Psephurus gladius)
A river giant vanishes

One of the world's largest freshwater fish is on the verge of going extinct.

A three-year quest to find the giant Chinese paddlefish in the Yangtze river failed to sight or catch a single individual.

That means that the fish, which can grow up to 7m long, has not been seen alive for at least six years.

There remains a chance that some escaped the survey and survive, say experts, but without action, the future of the species is bleak.

The concern for the Chinese paddlefish is that its fate will parallel that of the Yangtze river dolphin, a large mammal species that was once abundant in the Yangtze river system, but has recently been declared extinct.

Chinese paddlefish (Psephurus gladius)
Some people call it the 'elephant fish' and we found out it swims on the surface of the water like a whale
Professor Wei Qiwei
Chinese Academy of Fisheries Science

A number of fish species vie for the position of the world's largest freshwater fish, including the arapaima (Arapaima gigas) of the Amazon river and the Mekong giant catfish (Pangasianodon gigas).

At up to 7m, the Chinese paddlefish (Psephurus gladius) is much longer than either, though it may not exclusively live in freshwater.

The fish is suspected to be anadromous, meaning it spends some of its life in marine waters before returning to the river to spawn. But it is so rare that little is known about its behaviour, life history, migration habits and population structure.

It is endemic to the Yangtze river system in China.

"It has special characteristics such as its sword-like rostrum. Some people call it the 'elephant fish' and we found out it swims on the surface of the water like a whale," says Professor Wei Qiwei, one of the leaders of the research team from the Chinese Academy of Fisheries Science in Jingzhou, China.

The last confirmed sighting of a Chinese paddlefish was made in the river on 24 January 2003.

Now scientists have published in the Journal of Applied Ichthyology the results of a three-year survey to find and locate the fish.

Professor Wei and colleagues surveyed the upper Yangtze river between Xinshi, Sichuan Province and Chongqing, covering a distance of 488.5km.

Most of this stretch of water lies within the Upper Yangtze National Nature Reserve, a protected area.

Elusive target

Between 2006 and 2008, the team used a number of boats to deploy 4762 setlines, 111 anchored setlines and 950 drift nets in a bid to catch the fish.

They failed to catch a single individual.

The team also used hydroacoustic equipment that beams sound through the water to create a picture of the river and anything in it.

This identified nine possible targets, of which two could be paddlefish, say the researchers. But they could not confirm these finds.

The fish now appears on the brink of extinction, say the scientists.

Record-breaking freshwater fish (weights not included if unknown):
Mekong giant catfish 2.7m, 293kg
European or wels catfish 4.57m, 336.3kg
White sturgeon 3.8m
Amazon arapaima 2.48m, 147kg
Chinese paddlefish 7m

They speculate that some paddlefish may have eluded the research team, avoiding its nets and capture methods.

Professor Wei also thinks that some younger, smaller paddlefish may also still exist.

"The individuals born in the late 1980s and early 1990s should survive in the wild, since the Yangtze river system is large and it has some complicated habitats where the paddlefish could hide," he says.

But without intervention, the future for the species is bleak.

"It is not a good future for the species. Maybe we have only ten years to save the species according to the estimated life span of 30 to 40 years," Professor Wei says.

"The offspring born in 1990 will be 30 years old by 2020. It is impossible for the species to be a viable population by natural reproduction. With the current situation of ecology and environment in the Yangtze river, man assistant measures have to be taken."

With so few fish left the team proposes that modern reproduction methods need to be considered, such as using surrogates to rear the fish in captivity.

Other techniques may include preserving genetic material, cloning, or gynogenesis, where fish eggs are coerced into developing via parthenogenesis.

However the team need to find live paddlefish in order to be able to start this process.

From the middle of last century the population of Chinese paddlefish has declined rapidly due to overfishing, habitat degradation and pollution.

The construction of the Gezhouba dam in 1981 on the Yangtze river also created a barrier to the migrating fish which further affected fish stocks.

The species has been listed as critically endangered on the International Union for the Conservation of Nature's Red List of Threatened Species since 1996.

Last chance to find

The team believe the upper Yangtze is probably one of the last places that the fish may be present and propose to focus their efforts there.

They also hope to be in a position to act if any fish materialise on the river.

"In the last three years, we have been trying to set a quick-response network along the upper-stem of the Yangtze river to save accidental catches of the paddlefish," Professor Wei says.

"However, the network not only costs money and time, but is also a great challenge."