Evolution of spiders and their relatives


This 6 August 2019 video is about the evolution of spiders and their Chelicerata relatives.

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New spider species gets fashion designer’s name


This October 2015 video says about itself:

Jotus remus, an Australian species of spider I discovered on 30 December 2014 when I came home from a camping trip and found it sitting on my luggage when unloading the car. Perhaps interesting to note that I had intentionally left my camera gear at home so I would not be tempted to look for spiders.

This spider was named and described in a paper that David Hill and myself published in the journal Peckhamia.

The courtship behaviour of this spider is extraordinary. Both play a kind of cat and mouse game and when I published this video I still did not know why they behaved in that way. It took almost a year to solve the puzzle and it happened when bringing together virgin females and males, you can see what happens then in the sequel to this video, Spid-a-boo2.

I watched female and males engaging in this way for many hours and regardless of how long the male tried a female that attacked him would not mate. This behaviour is NOT to tire out the female, tiredness plays no role here. The aim is to find a female that is receptive, one that has not yet mated. Instead of chasing the male with his paddle receptive females become calm and placid almost immediately when seeing the male’s paddle appearing over the edge of a leaf and it only takes a couple of minutes for them to decide to mate.

The clips I used in this video are only a fraction of what I originally shot. You can find many more scenes in my album on Vimeo.

The music for this clip was composed, played and recorded by cellist Kristin Rule. I love her work and I am glad she agreed to help me with this little clip. Research, camera, editing: Jurgen Otto Camera gear used: Canon C100 and 100mm macro lens For more on my work visit me on Facebook.

And now, newly discovered relatives of this spider species.

From ScienceDaily:

Trendy on eight legs: Jumping spider named after fashion czar Karl Lagerfeld

July 2, 2019

New to science species of Australian jumping spider was named after Hamburg-born fashion icon Karl Lagerfeld (1933-2019) after the arachnid reminded its discoverers of the designer. Intrigued by its distinct ‘downplayed’ black-and-white colours, the Hamburg-Brisbane-Melbourne team likened the spider’s appearance to Lagerfeld’s trademark style: his white hair and Kent collar that contrasted with the black sunglasses and gloves.

Thus, the curious species, now officially listed under the name Jotus karllagerfeldii was described in the open-access journal Evolutionary Systematics by Dr Danilo Harms of the Center for Natural History of the University of Hamburg (CeNak), Dr Barbara Baehr, Queensland Museum (Brisbane, Australia) and Joseph Schubert, Monash University (Melbourne).

When compared with other members in the ‘brushed’ jumping spider genus Jotus, the novel species clearly stands out due to its black-and-white legs and tactile organs (pedipalps), whereas the typical representative of this group demonstrates striking red or blue colours.

“The animal reminded us with its colours of the reduced style of Karl Lagerfeld. For example, we associate the black leg links with the gloves he always wore,” Danilo Harms explains.

In fact, what was to be now commonly referred to as Karl Lagerfeld’s Jumping Spider was identified amongst specimens in the Godeffroy Collection. Kept at CeNak, the historical collection was originally compiled by the inquisitive and wealthy tradesman from Hamburg Johann Cesar Godeffroy, who financed several expeditions to Australia back in the 19th century. Here, the research team identified another link between Australia, Godeffroy, Hamburg and Jotus karllagerfeldi.

Besides the tiny (4 to 5 mm) arachnid, whose pedipalps resemble a white Kent collar, the scientists describe another seven new to science species and add them to the same genus. Two of those, Jotus fortiniae and Jotus newtoni, were also named after inspirational figures for their hard work and creativity: educator, molecular biologist and science communicator Dr Ellen Fortini (Perth College, Western Australia) and keen naturalist and photographer Mark Newton. All novel species were found either in the Godeffroy Collection or amongst the jumping spiders housed at Queensland Museum.

Surprisingly, even though the genus Jotus comprises numerous species found all over Australia, there is not much known about these spiders. An interesting feature, according to the scientists behind the present study, are the huge telescopic eyes, which allow for spatial vision. The Jotus species need this ability in foraging, since they do not weave webs, but rather hunt in the open. Thus, they have evolved into extremely fast and agile hunters, capable of jumping short distances.

Curiously, back in 2017, the team of Barbara and Danilo, joined by Dr Robert Raven from Queensland Museum, described another previously unknown, yet fascinating species: a water-adapted spider, whose sudden emergence at the coastline of Australia’s “Sunshine State” of Queensland during low tide in January brought up the association with reggae legend Bob Marley and his song “High Tide or Low Tide.” The species, scientifically known as Desis bobmarleyi, was also published in Evolutionary Systematics.

Spiders start out social but later turn aggressive after dispersing and becoming solitary, according to a study publishing July 2 in the open-access journal PLOS Biology by Raphael Jeanson of the National Centre for Scientific Research (CNRS) in France, and colleagues: here.

Spiders use electricity to fly


This 25 April 2019 video says about itself:

How Spiders Use Electricity to Fly | Decoder

Can spiders fly? When you think of the greatest aviators in the natural world, you probably think of the usual winged suspects like birds, bees, and butterflies. But some of the earth’s eight-legged creatures also have specialized ways of soaring through the skies—no wings necessary.

Researchers at McMaster University who rush in after storms to study the behaviour of spiders have found that extreme weather events such as tropical cyclones may have an evolutionary impact on populations living in storm-prone regions, where aggressive spiders have the best odds of survival: here.

Horseshoe crabs, really relatives of spiders, scorpions


This 3 March 2019 video from the USA says about itself:

It’s Cameraman Tim’s debut as a field correspondent! Tim travels to Cape Cod, Massachusetts to investigate the annual Horseshoe Crab invasion!

From the University of Wisconsin-Madison in the USA:

Horseshoe crabs are really relatives of spiders, scorpions

March 8, 2019

Summary: By analyzing troves of genetic data and considering a vast number of possible ways to examine it, scientists now have a high degree of confidence that horseshoe crabs do indeed belong within the arachnids.

Blue-blooded and armored with 10 spindly legs, horseshoe crabs have perhaps always seemed a bit out of place.

First thought to be closely related to crabs, lobsters and other crustaceans, in 1881 evolutionary biologist E. Ray Lankester placed them solidly in a group more similar to spiders and scorpions. Horseshoe crabs have since been thought to be ancestors of the arachnids, but molecular sequence data have always been sparse enough to cast doubt.

University of Wisconsin-Madison evolutionary biologists Jesús Ballesteros and Prashant Sharma hope, then, that their recent study published in the journal Systematic Biology helps firmly plant ancient horseshoe crabs within the arachnid family tree.

By analyzing troves of genetic data and considering a vast number of possible ways to examine it, the scientists now have a high degree of confidence that horseshoe crabs do indeed belong within the arachnids.

“By showing that horseshoe crabs are part of the arachnid radiation, instead of a lineage closely related to but independent of arachnids, all previous hypotheses on the evolution of arachnids need to be revised,” says Ballesteros, a postdoctoral researcher in Sharma’s lab. “It’s a major shift in our understanding of arthropod evolution.”

Arthropods are often considered the most successful animals on the planet since they occupy land, water and sky and include more than a million species. This grouping includes insects, crustaceans and arachnids.

Horseshoe crabs have been challenging to classify within the arthropods because analysis of the animals’ genome has repeatedly shown them to be related to arachnids like spiders, scorpions, mites, ticks and lesser-known creatures such as vinegaroons. Yet, “scientists assumed it was an error, that there was a problem with the data,” says Ballesteros.

Moreover, horseshoe crabs possess a mix of physical characteristics observed among a variety of arthropods. They are hard-shelled like crabs but are the only marine animals known to breathe with book gills, which resemble the book lungs spiders and scorpions use to survive on land.

Only four species of horseshoe crabs are alive today, but the group first appeared in the fossil record about 450 million years ago, together with mysterious, extinct lineages like sea scorpions. These living fossils have survived major mass extinction events and today their blood is used by the biomedical industry to test for bacterial contamination.

Age is just one of the problems inherent in tracing their evolution, say Ballesteros and Sharma, since searching back through time to find a common ancestor is not easy to accomplish. And evidence from the fossil record and genetics indicates evolution happened quickly among these groups of animals, convoluting their relationships to one another.

“One of the most challenging aspects of building the tree of life is differentiating old radiations, these ancient bursts of speciation,” says Sharma, a professor of integrative biology. “It is difficult to resolve without large amounts of genetic data.”

Even then, genetic comparisons become tricky when looking at the histories of genes that can either unite or separate species. Some genetic changes can be misleading, suggesting relationships where none exist or dismissing connections that do. This is owed to phenomena such as incomplete lineage sorting or lateral gene transfer, by which assortments of genes aren’t cleanly made across the evolution of species.

Ballesteros tested the complicated relationships between the trickiest genes by comparing the complete genomes of three out of the four living horseshoe crab species against the genome sequences of 50 other arthropod species, including water fleas, centipedes and harvestmen.

Using a complex set of matrices, taking care not to introduce biases in his analysis, he painstakingly teased the data apart. Still, no matter which way Ballesteros conducted his analysis, he found horseshoe crabs nested within the arachnid family tree.

He says his approach serves as a cautionary tale to other evolutionary biologists who may be inclined to cherry-pick the data that seem most reliable, or to toss out data that don’t seem to fit. Researchers could, for example, “force” their data to place horseshoe crabs among crustaceans, says Sharma, but it wouldn’t be accurate. The research team tried this and found hundreds of genes supporting incorrect trees.

Ballesteros encourages others to subject their evolutionary data to this kind of rigorous methodology, because “evolution is complicated.”

Why horseshoe crabs are water dwellers while other arachnids colonized land remains an open question. These animals belong to a group called Chelicerata, which also includes sea spiders. Sea spiders are marine arthropods like horseshoe crabs, but they are not arachnids.

“What the study concludes is that the conquest of the land by arachnids is more complex than a single tradition event,” says Ballesteros.

It’s possible the common ancestor of arachnids evolved in water and only groups like spiders and scorpions made it to land. Or, a common ancestor may have evolved on land and then horseshoe crabs recolonized the sea.

“The big question we are after is the history of terrestrialization,” says Sharma.

For Ballesteros, who is now studying the evolution of blindness in spiders living deep within caves in Israel, his motivations get to the heart of human nature itself.

“I get to look with childish curiosity and ask: ‘How did all this diversity come to be?'” he says. “It’s incredible what exists, and I never thought I would have the privilege to be able to do this.”

The study was funded by the M. Guyer postdoctoral fellowship and supported by National Science Foundation grant IOS-1552610.

New tarantula species discovery in Angola


This 9 February 2019 video says about itself:

Let’s call it “The Mega Horned Baboon Tarantula” – what do you think?
Ceratogyrus attonitifer is a new species described by the arachnologist Ian Engelbrecht. This baboon tarantula is native to the country of Angola and has an astonishing horn – something we’ve never seen before, covering almost the entire opisthosoma of the baboon tarantula spider.

It’s remarkable – watch the video, enjoy its beauty and let’s hope for more pictures and videos of this new baboon tarantula species soon!

From ScienceDaily:

New tarantula species from Angola distinct with a one-of-a-kind ‘horn’ on its back

February 12, 2019

A new to science species of tarantula with a peculiar horn-like protuberance sticking out of its back was recently identified from Angola, a largely underexplored country located at the intersection of several Afrotropical ecoregions.

Collected as part of the National Geographic Okavango Wilderness Project, which aims to uncover the undersampled biodiversity in the entire Okavango catchment of Angola, Namibia and Botswana, thereby paving the way for sustainable conservation in the area, the new arachnid is described in a paper published in the open-access journal African Invertebrates by the team of Drs John Midgley and Ian Engelbrecht.

Although the new spider (Ceratogyrus attonitifer sp.n.) belongs to a group known as horned baboon spiders, the peculiar protuberance is not present in all of these species. Moreover, in the other species — where it is — the structure is completely sclerotised, whereas the Angolan specimens demonstrate a soft and characteristically longer ‘horn’. The function of the curious structure remains unknown.

The new tarantula’s extraordinary morphology has also prompted its species name: C. attonitifer, which is derived from the Latin root attonit- (“astonishment” or “fascination”), and the suffix -fer (“bearer of” or “carrier”). It refers to the astonishment of the authors upon the discovery of the remarkable species.

“No other spider in the world possesses a similar foveal protuberance,” comment the authors of the paper.

During a series of surveys between 2015 and 2016, the researchers collected several female specimens from the miombo forests of central Angola. To find them, the team would normally spend the day locating burrows, often hidden among grass tufts, but sometimes found in open sand, and excavate specimens during the night. Interestingly, whenever the researchers placed an object in the burrow, the spiders were quick and eager to attack it.

The indigenous people in the region provided additional information about the biology and lifestyle of the baboon spider. While undescribed and unknown to the experts until very recently, the arachnid has long been going by the name “chandachuly” among the local tribes. Thanks to their reports, information about the animal’s behaviour could also be noted. The tarantula tends to prey on insects and the females can be seen enlarging already existing burrows rather than digging their own. Also, the venom of the newly described species is said to not be dangerous to humans, even though there have been some fatalities caused by infected bites gone untreated due to poor medical access.

In conclusion, the researchers note that the discovery of the novel baboon spider from Angola does not only extend substantially the known distributional range of the genus, but can also serve as further evidence of the hugely unreported endemic fauna of the country:

“The general paucity of biodiversity data for Angola is clearly illustrated by this example with theraphosid spiders, highlighting the importance of collecting specimens in biodiversity frontiers.”

Apart from the described species, the survey produced specimens of two other potentially new to science species and range expansions for other genera. However, the available material is so far insufficient to formally diagnose and describe them.

Spiders dating, dangerous or delicious?


This 11 February 2019 video from the Natural History Museum in London, England says about itself:

What are the secrets of spider dating? | Natural History Museum

For some spiders, choosing the wrong mate can be deadly. Jan Beccaloni, Curator of Arachnida and Myriapoda, explains some of the tactics male spiders use to avoid becoming their mate’s next meal.

This spider slingshots itself at extreme speeds to catch prey. The Peruvian spider and its web go flying with 100 times the acceleration of a cheetah. By Emily Conover, 10:19am, March 6, 2019.