A new species of pirate spider has been discovered on a South Atlantic island.

The spider Aerolisa lives on blackscale ferns, but it can also live on other plants. Credit: Lisa Fowler / St Helena National Trust

On a remote tropical island in the Atlantic Ocean, a pair of Maroond pirates have been discovered. Although they lack eye patches and cut glasses, two new species of pirate spider certainly live up to their nautical namesake, their ability to violently grab the webs of other spiders and kill the occupants. Refers to habit.

After being confused about a closely related species, two new spiders have been lurking on St. Helena for decades. Now newly recognized, it is hoped that the spiders will provide further impetus to preserve the island’s endangered cloud forest.

“Our work shows that two species new to science existed in the cloud forest, but were thought to exist for more than four decades,” says Danny Sherwood, lead author of a new study on these spiders. “They are a single, common, species. They are found in many parts of the world, including Britain.”

“These spiders don’t just have interesting morphology. Their type areas are in one of the most unique and endangered habitats in the world: the St. Helenian Cloud Forest. Knowing which species are there and which are not is important. are, helping their conservation efforts. The cloud forest as a whole.”

Facts and evidence It was published in European Journal of Taxonomy.

An island of invertebrates

Found 2,000 kilometers off the coast of West Africa, St. Helena is one of the most isolated places on Earth. With environments ranging from tropical forests to desert beaches, it has developed a biodiversity unlike anywhere else.

The cloud forest found around the island’s peaks is particularly important. The trees capture water from the clouds, which then drains to the lower parts of the island and accounts for about 60% of the water that falls on St. Helena each year.

It supports a variety of unique plants, such as cabbage trees and blackscale ferns, which in turn host at least 120. Not found anywhere in the world.

Unfortunately, very little of this original forest remains. Historical clearance of forest for livestock and crops, as well as the introduction of invasive species, has left only small, scattered patches.

The UK Government, in collaboration with the St Helena National Trust, the RSPB and the Species Recovery Trust, is working to address these gaps through the St Helena Cloud Forest Project. But that means it’s more important than ever to find out what’s really going on. .

One species that was thought to have made the forest its home was the Ero Ifana, a pirate. Commonly found in Western Europe. It was believed to have been inadvertently introduced over the past 500 years, but when the research team went back to examine the spider’s specimens, they realized something was wrong.

Dr Ben Price, senior curator in charge of small orders at the Natural History Museum, was a co-author of the study.

“We were working on a project to improve the DNA reference library for St. Helena, so that the people of the island could more easily monitor their biodiversity,” Ben explains. “It’s using museum specimens and freshly collected compounds to help fill in the gaps in our knowledge.”

“Danny already suspected that Aerofauna might not be all that it seems, so we added it to the mix. It turns out that there isn’t just one pirate spider on the island, but two! There are different species.”

A new species of pirate spider has been discovered on a South Atlantic island.

The spider Aero Natashi It was last captured in the 1970s, so little is known about its lifestyle. Credit: Sherwood et al., licensed under CC BY 4.0 through European Journal of Taxonomy

How were pirate spiders discovered?

Closer examination of the spiders provided the first clues that they were of a different species. Ero lizae has two spike-like structures on the back of the body, while Ero natashae is significantly smaller. DNA evidence also played a role in proving that these spiders were their own species.

“There are many cryptic species for which DNA is one of the few, if only, ways to distinguish between them,” says Ben. “While DNA in typical museum specimens decays rapidly in the first decade or so after collection, it slows significantly thereafter.”

“This means that sequencing the DNA of a 150-year-old sample is no different than sequencing a 50-year-old sample, so we were able to use methods developed for ancient DNA to Genetic material could be extracted from two legs of lisa. Its genetics are significantly different from Aerofana, indicating that they cannot be the same species.”

Based on this information, the researchers were confident enough to formally describe the two new species from specimens held at the Natural History Museum, London and the Royal Museum of Central Africa in Belgium.

The species was named in honor of Lisa Fowler and Natasha Stevens, two conservationists working at the St Helena National Trust.

“Naming these species after two friends and colleagues who helped me greatly during my visit to St. Helena in 2022, and who have devoted many years to saving St. Helena invertebrates,” says Danny. It was a pleasure to spend.”

Although little is currently known about these spiders, it is hoped that further research will help to determine how they live, and how they can be allowed to thrive.

More information:
Danniella Sherwood et al., Two new sympatric species of the pirate spider genus Ero CL Koch, 1836 from the cloud forest of St. Helena Island, South Atlantic Ocean (Araneae: Mimetidae), European Journal of Taxonomy (2024). DOI: 10.5852/ejt.2024.921.2417

This story is reprinted courtesy of the Natural History Museum. Read the original story Here.

Reference: New species of pirate spiders discovered on South Atlantic island (2024, February 16) https://phys.org/news/2024-02-species-pirate-spiders-south-atlantic.html February 17, 2024 Obtained from

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