Why do fan-throated lizards come in such a wide variety?

Fan-throated lizards are a group mostly of colorful and some plain lizards that live on sandy beaches and barren plateaus of the Indian subcontinent.

Colourful or drab, all males have a special ornament to lure females – a loose flab of skin under the throat. Doesn’t sound very attractive, does it? But that does it for them. Here’s how: to draw the attention of females, males get their feet on a rock (or any raised platform), stretch their body and extend their loose under-throat into a fan. Hence the name.

1. A fan-throated lizard (Sarada superba)

The first species of fan-throated lizard was found in India back in 1829. Since, there have been rumours of more species in the scientific community but discoveries have been few. That changed in 2016 when scientists found 5 new species in one go. Now, they have found that there are at least 15 species, including the ones discovered in 2016.

Sarada_darwini_IMG_0381

The sheer variety owes itself to changes in climate that happened millions of years ago – with the arrival of monsoons, rains became seasonal and grasslands expanded. This worked in favour of fan-throated lizards as they adapted to these changes and morphed into several species we see today.

I wrote about how a changing climate impacted the lizards for Mongabay-India today. You may also like my other pieces about these beautiful bright beasts published here at The BBC and here at The Wire in 2016.

3. Sitana sivalensis Credit - V. Deepak.JPG

Photo credits: V. Deepak

Traffic noise impacts frog survival

If you’ve ever lived near a busy road, you’re familiar with the noise of cars whooshing by and ear-piercing honks. Traffic noise is a well-known source of stress in humans. Now, a team of researchers has found that it can cause increased stress levels in frogs too. And aside from a spike in stress, traffic noise can have other negative effects on the European tree frog (Hyla arborea), such as suppressed immunity and a dulling of males’ vocal sacs. The team’s results were published last week (January 11) in Conservation Biology.

To study the effects of road noise on frogs, Thierry Lengagne of the University of Lyon, France, and colleagues first recorded noise from a nearby high-traffic road. The scientists then played back the recording to 20 male frogs in the lab. After 10 days of 24/7 exposure to traffic noise at 76 decibels, the frogs showed signs of increased stress.

Read the full story over at The Scientist.

Photo credit: Thierry Lengagne

Viral outbreak threatens the survival of amphibians

A viral outbreak is killing amphibians, including frogs, toads and salamanders, in the Picos de Europa National Park in Spain. As if the imminent local extinction of amphibians wasn’t grim enough in itself, their disappearance, scientists fear, could also tip the ecological balance in favour of species amphibians feed on.

A team of researchers from Spain and the United Kingdom started monitoring amphibians in the national park in 2005 when they first noticed a die-off from viral infection. The team is now the first to report two related, highly infectious viruses – the ranaviruses – simultaneously infecting multiple amphibian species at several locations in Spain.

Ranavirus infection is often associated with severe disease and mass deaths of amphibians but previously decline of only one amphibian species had been [quantified]. Here, we show three amphibian species showing simultaneous population collapses in the Picos National Park,” says Stephen J. Price, researcher at University College London and an author of the study published today in the journal Current Biology.

Read the rest of the article at Earth Touch.

Snails suffer genetic damage from pollution

Pollutants from oil spills, shipping activities and industrial effluents could be the reason for genetic damage in snails of Goa, research has found. The extent of genetic damage in snails could serve as a measure of the health of a marine ecosystem, it says.

A team of researchers collected snails of the species Morula granulata from nine locations along the coast of Goa – a major tourism and seafood industry hotspot of India. The team learnt that the extent of damage in the genetic material (DNA) of these snails increased with rising levels of toxic pollutants along the coast.

“When toxic contaminants, such as polycyclic aromatic hydrocarbons (PAHs), are taken up by marine organisms, the snails will try to metabolize the contaminants for subsequent elimination. The toxins are degraded, ultimately converted into by-products and removed from the body,” explains A. Sarkar, lead author of the study at Global Enviro-Care, Goa. “But during their metabolism, reactive intermediate stages are formed, resulting in DNA strand breaks.”

Sarkar and co-workers used molecular biomarker techniques to assess breaks in the DNA isolated from snails and determined its integrity. They observed that DNA integrity reduced by as much as 56% at one of the most polluted of the chosen sites (Hollant) compared to the non-polluted, reference site (Arambol) located farther away from the industrial belt. They found the concentration of PAHs in sediments to be highest around Hollant (5.17 μg/g) and lowest at Arambol (1.65 μg/g) among all sites.

Read the rest at IndiaBioScience.

Photo credit: A. Sarkar