Finding seashells on the seashore

The smell of sea hangs thick in the air as we gather round and listen to the dos and don’ts. “Don’t pick up anything even if it seems beautiful,” Sejal Mehta tells a motley group of students and professionals. “It might sting you and you might die.”

We have assembled to spot wildlife in a metropolis where the uninitiated might not expect to find any. After all, the city of dreams, Mumbai is famous for its Bollywood ‘stars’ – not the stars that live or wash up on its shores. The city is better known by its dabbawalas clad in white than the otherworldly creatures decked up in shells or tentacles. But this is why we are here. A citizen science initiative called the Marine Life of Mumbai has organized a shore walk to bring the city’s most underrated stars into the spotlight.

Mumbai’s unexplored shores have more than 50 species of crabs, Pradip Patade, the co-founder of Marine Life of Mumbai, tells me. Patade’s day job as a watersports instructor had primed him to launch the initiative. Every day at work he would come across creatures of all sorts on the beach and in the open waters. But 2013 became a turning point for him.

Patade was on lifeguard duty when several people were stung by stingrays, which come to shallow waters to give birth and sting when stepped on. Patade, shocked by the lack of knowledge about these animals, wanted to do something. So, he started sharing his marine finds on Facebook. Years later, the naturalist teamed up with two researchers and thus, Marine Life of Mumbai was born in February 2017. It started out as an online repository of information but then Patade and his team thought that taking people along on walks would make more of a difference.

image-1Barnacles are crustaceans that can be found aplenty on Mumbai’s rocky shores 

Two years and several shore walks later, Marine Life of Mumbai has filed 1300 records of 315 species on the citizen science app iNaturalist. Meanwhile, its band of volunteers has continued to expand. The volunteers help out as resource persons for the walks, Patade says, or with identifying species, writing content for social media, and running the website.

Writer and editor Sejal Mehta has been contributing to Marine Life of Mumbai for over a year. The intertidal zone, exposed at low tide, was completely new to her when she joined. Until then, Mehta’s notion of sealife was “dolphins and whales.” Today, she is introducing us to the intertidal zone and its denizens — with metallic sea stars dangling from her ears.

Life on the city shores

Mumbai’s coastline has a variety of habitats – sandy shores, rocky shores, mudflats and mangroves, Mehta tells us. Juhu beach, where we are, has three of these – sandy, rocky and muddy – along its six-kilometre stretch. I am thinking we are in for a treat when Patade hints at the unpredictability of wildlife. You don’t always see a tiger on a tiger safari, he quips.

Just moments later, though, he points at what looks like abstract sand art. Tiny orbs of sand are strewn all around us, some stacked atop each other into miniature sandcastles. The work of sand bubbler crabs, which live in burrows and come out to feed at low tide, we are told. The orbs and castles that dot the beach are essentially sand grains that the crabs have filtered for nutrients.

We didn’t see the crabs as they remained hidden in their burrows – thanks to the big friendly giants walking overhead. But now, it became impossible for us to walk without thinking of the many lives in the sand below our feet.

image-2Patterns indicate the presence of sand bubbler crabs 

As we try keeping up with Patade, we spot a pile of hermit crabs arguing over shells. When a hermit crab grows out of one shell, it has to find – and often fight – for another, bigger shell. The shell it abandons becomes available for a smaller hermit crab to move in. But without one, this soft-bodied crab is seafood for the hungry crows and shorebirds lurking nearby. Empty snail shells are prime real estate here, we realise as we leave the hermits to themselves.

And soon, we chance upon a sea anemone. It would fit on the palm of your hand, except that stinging cells line its tentacles. Waves come and go but the anemone remains firmly anchored to the spot – only its tentacles dance in tune with the ebb and flow. Some anemones form symbiotic associations with other animals such as hermit crabs, Mehta volunteers. But the most amazing thing, she says, is that they can multiply by splitting into two. Anemones can also reproduce sexually.

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A sea anemone anchored in the sand          

Among the rocky outcrops off the sandy shore, we find barnacles attached to rocks, a baby octopus swimming in the tide pool, a moray eel seeking cover, colourful sea sponges on jagged rocks, crabs hidden in crevices, camouflaged sea stars, and tiny porcelain crabs dressed in stripes.

Mumbai-based photographer Pratha Narang says she didn’t know that a stone’s throw from her home, you could find so many small and wonderful creatures. “I was overwhelmed by their presence.” Other participants echo this. Teacher Kapil Joshi says he was amazed by the knowledge of the Marine Life of Mumbai group. “I am going to share it with my students at school.”

As the tide returns, we reluctantly leave the company of the weird and wonderful behind. No one was bitten or stung but we all left starstruck, as it often happens in Mumbai.

image-4Porcelain crabs shed their limbs to escape predators – hence the name             

(All images are copyright of Richa Malhotra. This article was written for Mongabay-India.)

Caterpillar vs. Beetle: Who wins?

I have a new video story up at Science magazine about an amazing moth caterpillar that fights off things that try to eat it, including beetles that are called ‘caterpillar hunters’. Check it out, folks!

The accompanying short story is available to read here.

Multimedia credit: Shinji Sugiura

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.

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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

Inside the secret world of bamboo-breeding frogs

Meet the white-spotted bush frog, a species that is fascinating on several counts. For one, it breeds inside bamboos (yes, in the hollows of the fast growing woody grasses).

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To convince a female to have kids with him, a male frog first finds a nice spot – a bamboo stem with a tiny hole just big enough to get through – and then sings to impress.

If a female likes it, she enters the bamboo, lays her eggs and immediately calls it quits. Daddy babysits alone (and mamma moves on to make more babies).

Image-3 Male guarding eggs
A month later, their round see-through eggs hatch directly into mini versions of their parents, instead of tadpoles.
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The florescent froglets stay put for a while before going it alone. Until they leave, their doting dad guards them round the clock, forgoing his hunt for food. He eats insects that stray into the bamboo cavity – things like ants and flies.
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While daddy does his duty, he aggressively croaks to warn other male frogs against stepping on his patch.

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And with good reason: rival males can make a quick meal of his eggs. They are hungry and, it turns out, cannibals. Eggs, as is obvious, are rich in nutrients and if left behind by their dad, have little chance of survival. Scientists recently uncovered these aspects of the bamboo-breeding frogs using an endoscope – a medical device typically used to peer inside our bodies.

What makes matters worse for the frogs, besides cannibalism, is that they are a critically endangered species existing nowhere but in India’s Western Ghats, a chain of mountains alongside the country’s west coast.

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And given the harvesting pressure facing their bamboo nursery, the frogs need all the help they can get. Finding out where the frogs live outside of reserves can identify bamboo stands worth protecting. Another useful thing would be to stop cutting down bamboo during monsoons, which is when the frogs breed. You can do your bit by spreading the word on a more detailed piece I wrote about these frogs for Mongabay-India.

Photo, sound and video credit: Seshadri K.S. (Many thanks to him for sharing the multimedia and giving permissions for use)

Mites squatting on spider webs steal food

In caves in Brazil, there lives a newly-discovered mite that is a freeloader. Groups of these mites live on a spider’s web and steal its food. They are the first mites known to do this.

Leopoldo Ferreira de Oliveira Bernardi at the Federal University of Lavras in Minas Gerais first saw live mites dotting a spider web by the entrance of Brazil’s Lapa Nova cave in 2007. The relationship between mites and spider immediately intrigued him.

After observing the same thing in another cave, Bernardi and his colleagues designed an experiment. They placed live bait – a cave moth – on the web of a recluse spider where mites were present.

The spider immediately attacked the moth and began feeding. But in the next 5 to 40 minutes, mites, which were previously scattered all over the web, gathered to feed on the moth.

To know what happens next, please visit New Scientist here.

Photo credit: Professor Rodrigo Lopes Ferreira

Salamander ate a frog for its final meal

The fossil of an extinct salamander is so exquisitely preserved that the remains of its last meal – a frog – can be seen in its gut.

The fossil comes from the site of the Quercy phosphorites in south-west France, which has thrown up many vertebrate fossils over the years. This is despite a large number of specimens probably being destroyed by phosphate mining in the 19th and 20th centuries.

The salamander fossil had remained largely forgotten in the French National Museum of Natural History for decades, until Jérémy Tissier of the JURASSICA Museum in Porrentruy, Switzerland, and his colleagues took a closer look.

They scanned the fossil using advanced imaging techniques, and named it Phosphotriton sigei after the phosphorus-rich sediments of Quercy. It is the only known fossil of this species, with a search in museums and sediment deposits coming up empty.

The salamander died 34 to 40 million years ago, yet aside from its skeleton, many of its soft tissues are preserved: an initial examination identified skin and a lung. These were protected by a process called permineralisation, sometimes loosely known as “mummification”. Under this mechanism, minerals from groundwater seep into a buried animal and fill any empty pockets, or even individual cells…

Read the whole story published in New Scientist here.

Photo credit: Jérémy Tissier

Scorpion fine-tunes its venom to ward off predators

The Australian rainforest scorpion (Liocheles waigiensis) has been found to be able to tweak the chemical profile of its venom following just weeks of exposure to a predator. The scorpion appears to do this to tailor its cocktail of venom toxins to deter predators that threaten it, rather than to hunt its preferred prey, insects.

The researchers presented scorpions in the laboratory with a taxidermied mouse to mimic a mammalian predator in the wild. They simulated mouse attacks on the scorpions three times a week for five weeks.

Towards the end of the experiment, the researchers found that the venom chemistry of predator-exposed scorpions differed from that of the unexposed scorpions. In exposed scorpions they found a relative increase in the production of some toxins that specifically target mammalian cells. Exposure to the dummy predator also decreased the production of toxins that scorpions use to catch prey such as insects.

Read the rest of the story here at Chemistry World.

Photo credit: Mark Marathon CC-BY-SA