Mother spider protects eggs


This 17 October 2017 video shows a female wasp spider making a golf ball size cocoon to protect her eggs. A cocoon may contain hundreds of eggs.

Marijke Scheffer from the Netherlands made this video.

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Spider and fly, video


This 3 October 2017 video shows a cellar spider trying to wrap silk around a hoverfly.

Rob Bruijnen in the Netherlands made this video.

New Caribbean spider named after Bernie Sanders


This 27 September 2017 video from the USA is called New spider species named after Obamas, DiCaprio.

From the University of Vermont in the USA:

Discovery: Bernie Sanders spider

September 26, 2017

A scientist at the University of Vermont and four of his undergraduate students have discovered 15 new species of “smiley-faced” spiders — and named them after, among others, David Attenborough, Barack Obama, Michelle Obama, Leonardo DiCaprio, and Vermont Senator Bernie Sanders.

You won’t find them in Washington, DC, Hollywood, or Vermont — but on Caribbean islands and other southern spots you might now get a glimpse of Spintharus davidattenboroughi, S. barackobamai, S. michelleobamaae, and S. berniesandersi as well as S. davidbowiei and S. leonardodicaprioi.

“This was an undergraduate research project,” says Ingi Agnarsson, a spider expert and professor of biology at UVM who led the new study. “In naming these spiders, the students and I wanted to honor people who stood up for both human rights and warned about climate change — leaders and artists who promoted sensible approaches for a better world.”

The study was published September 26 in the Zoological Journal of the Linnean Society.

Why Bernie?

Until now, the beautiful, yellow, smiley-faced spiders in the genus Spintharus — named for a smiley face pattern on their abdomens — has been thought to have one widespread species “from northern North America down to northern Brazil,” Agnarsson says.

However, when a research team from the Caribbean Biogeography Project (“CarBio”) — spearheaded by Agnarsson and Greta Binford at Lewis & Clark College — examined spiders from Jamaica, Cuba, the Dominican Republic, Puerto Rico, the Lesser Antilles, Florida, South Carolina, Costa Rica, Mexico, and Colombia — they discovered that one widespread species was actually many endemic species. Using CarBio genetic work, and the Vermont students’ painstaking photography and lab work, the team — with support from the National Science Foundation — was able to identify and formally describe fifteen new species. “And if we keep looking, we’re sure there are more,” Agnarsson said.

Each student who helped describe the spiders also got to name a few of them — and some were named for beloved family members, “but we all named the Bernie Sanders spider”, says Lily Sargeant, one of the students who worked on the project, and who graduated from UVM last year. “We all have tremendous respect for Bernie. He presents a feeling of hope.”

“That spider species will be named after Bernie forever,” says Ben Chomitz, another of the student researchers.

“Our time on this earth is limited,” says Lily Sargeant. “But I think that ideas are not that way. It is my hope that through naming that spider after Bernie we can remember the ideas that he has at this pivotal point in the life of our nation.”

For student Chloe Van Patten, her naming process goes back to what she calls a high school “obsession” with actor Leonardo DiCaprio. “I’m over my crush, but now that he’s involved in environmental issues, I love him even more. So I named a spider after him hoping that if he read our study,” says the recent UVM graduate, “he might go out to dinner with me and talk about climate change.”

Conservation concerns

The Caribbean region has long been known to scientists as a major global hotspot for biological diversity. The leading spider expert on the Spintharus genus in earlier decades, Herbert W. Levi (1921-2014), had concluded that differences he observed in these spiders across a wide swath of geography represented variation within one species. But newer molecular techniques deployed by the project’s leaders, Agnarsson and Binford, show otherwise. “These are cryptic species,” Agnarsson says. “As Dr. Levi’s work clearly showed, they’re hard to tell apart by looking at them.” But the DNA data are clear: these spiders have not been interbreeding — exchanging genes — for millions of years.

“Thoughts about conservation change dramatically when you go from having a common, widespread species to an endemic on, say, Jamaica that has very specific conservation needs,” Agnarsson says.

“All the sudden we have fifteen-fold increase in diversity in this particular group — just because we did a detailed study,” says Agnarsson. “That tells us something about biodiversity in general. The more we look, the more we discover.” Conservation biology, the team notes, fundamentally depends on good taxonomy, since preserving one widespread species is a radically different task than protecting the precise habitat of a genetically isolated, local species.

The Vermont students saw their lab work in a broad cultural light. “I’m a second-generation American and I’m black,” says Lily Sargeant. “It is through a diversity of perspectives that we achieve innovation in science and I appreciate how much the Obamas value diversity.”

“Here’s the thing,” says UVM scientist Ingi Agnarsson, “we need to understand and protect biodiversity in its many forms, and we felt compelled to recognize leaders that understand this.”

Prehistoric spider journey from Africa to Australia?


This video from Australia says about itself:

2 August 2017

This spider floated 6,000 miles across the Indian Ocean millions of years ago.

By Sarah Zielinski, 9:00am, August 15, 2017:

These spiders crossed an ocean to get to Australia

If you look at a map of the world, it’s easy to think that the vast oceans would be effective barriers to the movement of land animals. And while an elephant can’t swim across the Pacific, it turns out that plenty of plants and animals — and even people — have unintentionally floated across oceans from one continent to another. Now comes evidence that tiny, sedentary trapdoor spiders made such a journey millions of years ago, taking them from Africa all the way across the Indian Ocean to Australia.

Moggridgea rainbowi spiders from Kangaroo Island, off the south coast of Australia, are known as trapdoor spiders because they build a silk-lined burrow in the ground with a secure-fitting lid, notes Sophie Harrison of the University of Adelaide in Australia. The burrow and trapdoor provides the spiders with shelter and protection as well as a means for capturing prey. And it means that the spiders don’t really need to travel farther than a few meters over the course of a lifetime.

There was evidence, though, that the ancestors of these Australian spiders might have traveled millions of meters to get to Australia — from Africa. That isn’t as odd as it might seem, since Australia used to be connected to other continents long ago in the supercontinent Gondwana. And humans have been known to transport species all over the planet. But there’s a third option, too: The spiders might have floated their way across an ocean.

To figure out which story is most likely true, Harrison and her colleagues looked at the spider’s genes. They turned to six genes that have been well-studied by spider biologists seeking to understand relationships between species. The researchers looked at those genes in seven M. rainbowi specimens from Kangaroo Island, five species of Moggridgea spiders from South Africa and seven species of southwestern Australia spiders from the closely related genus Bertmainius.

Using that data, the researchers built a spider family tree that showed which species were most closely related and how long ago their most recent common ancestor lived. M. rainbowi was most closely related to the African Moggridgea spiders, the analysis revealed. And the species split off some 2 million to 16 million years ago, Harrison and her colleagues report August 2 in PLOS ONE.

The timing of the divergence was long after Gondwana split up. And it was long before either the ancestors of Australia’s aboriginal people or later Europeans showed up on the Australian continent. While it may be improbable that a colony of spiders survived a journey of 10,000 kilometers across the Indian Ocean, that is the most likely explanation for how the trapdoor spiders got to Kangaroo Island, the researchers conclude.

Such an ocean journey would not be unprecedented for spiders in this genus, Harrison and her colleagues note. There are three species of Moggridgea spiders that are known to live on islands off the shore of the African continent. Two live on islands that were once part of the mainland, and they may have diverged at the same time that their islands separated from Africa. But the third, M. nesiota, lives on the Comoros, which are volcanic islands. The spiders must have traveled across 340 kilometers of ocean to get there.

These types of spiders may be well-suited to ocean travel. If a large swatch of land washes into the sea, laden with arachnids, the spiders may be able to hide out in their nests for the journey. Plus, they don’t need a lot of food, can resist drowning and even “hold their breath” and survive on stored oxygen during periods of temporary flooding, the researchers note.

Beautiful spider web building time-lapse video


This video says about itself:

Beautiful Spider Web Build Time-lapse – BBC Earth

Using beautiful time-lapse photography the BBC Earth Unplugged team were able to film an Orb spider as it builds a beautifully structured web. If you enjoyed this animal slow motion video then check out our slow motion playlist here.

How spiders mastered spin control. Their silk subtly changes shape as it twists, slowing rotation. By Emily Conover, 7:00am, August 8, 2017.

Ant-mimicking jumping spiders protect themselves


This 2012 video is called Ant mimic jumping spider – Japan Myrmarachne.

From Cornell University in the USA:

Walking like ants gives spiders a chance

July 14, 2017

Summary: To avoid being eaten, some jumping spiders pretend to be ants, a new study has found. Protective mimicry is a remarkable example of adaptive evolution: Moths can be colored like butterflies and grasshoppers may look like tiger beetles. While most mimicry studies focus on traits like color and shape, the researchers in this work used multiple high-speed cameras and behavioral experiments to pinpoint how the spider’s movements mimic ants.

Humans aren’t the only actors on the planet. To avoid being eaten, some jumping spiders pretend to be ants, according to Cornell University research published in Proceedings of the Royal Society B.

Ants are aggressive at defending themselves: They are well-armed with bites, stings and formic acid. Ant-mimicking jumping spiders — Myrmarachne formicaria — in contrast, can’t do much more than run on their eight legs when attacked. Not surprisingly, insect predators tend to prefer spiders over ants, so appearing to be an ant confers significant protection.

Protective mimicry is a remarkable example of adaptive evolution: Moths can be colored like butterflies and grasshoppers may look like tiger beetles. While most mimicry studies focus on traits like color and shape, the researchers used multiple high-speed cameras and behavioral experiments to pinpoint how the spider’s movements mimic ants.

Ant-mimicking spiders walk using all eight legs but pause frequently to raise their forelegs to mimic ant antennae. When walking, they take winding trajectories of about five to 10 body lengths, which made them look like ants following pheromone trails. While the researchers could see what the spiders were doing thanks to high-speed cameras, many potential predators have slower visual systems, so that to them the mimics appear to be moving just like an ant would.

The researchers note that the findings “highlight the importance of dynamic behaviors and observer perception in mimicry.”

Amazing jumping spider video


This video says about itself:

Spider With Three Super Powers – The Hunt – BBC Earth

2 July 2017

Known for eating other spiders, Portia is a genus of the jumping spider that is able to leap up to 50 times her own body length. Captured by stunning close up footage, we get to witness this amazing spider use her super powers to dine on prey three times her size.