Tag: Madagascar

Spider eat spider: Scientists discover 18 new spider-hunting pelican spiders in Madagascar

In 1854, a curious-looking spider was found preserved in 50 million-year-old amber. With an elongated neck-like structure and long mouthparts that protruded from the “head” like an angled beak, the arachnid bore a striking resemblance to a tiny pelican. A few decades later when living pelican spiders were discovered in Madagascar, arachnologists learned that their behavior is as unusual as their appearance, but because these spiders live in remote parts of the world they remained largely unstudied–until recently.

At the Smithsonian’s National Museum of Natural History, curator of arachnids and myriapods Hannah Wood has examined and analyzed hundreds of pelican spiders both in the field in Madagascar and through study of pelican spiders preserved in museum collections. Her analysis, focused on spiders of the Eriauchenius and Madagascarchaea genera, sorted the spiders she studied into 26 different species–18 of which have never before been described. Wood and colleague Nikolaj Scharff of the University of Copenhagen describe all 26 pelican spider species in the Jan. 11 issue of the journal Zookeys.

Wood says pelican spiders are well known among arachnologists not only for their unusual appearance, but also for the way they use their long “necks” and jaw-like mouthparts to prey on other spiders. “These spiders attest to the unique biology that diversified in Madagascar,” she said.

Pelican spiders are active hunters, prowling the forest at night and following long silk draglines that lead them to their spider prey. When a pelican spider finds a victim, it swiftly reaches out and impales it on its long, fang-tipped “jaws,” or chelicerae. Then it holds the capture away from its body, keeping itself safe from potential counterattacks, until the victim dies.

Today’s pelican spiders are “living fossils,” Wood says–remarkably similar to species found preserved in the fossil record from as long as 165 million years ago. Because the living spiders were found after their ancestors had been uncovered in the fossil record and presumed extinct, they can be considered a “Lazarus” taxon. In addition to Madagascar, modern-day pelican spiders have been found in South Africa and Australia–a distribution pattern that suggests their ancestors were dispersed to these landmasses when the Earth’s supercontinent Pangaea began to break up around 175 million years ago.

Madagascar is home to vast numbers of plant and animal species that exist only on the island, but until recently, only a few species of pelican spiders had been documented there. In 2000, the California Academy of Sciences launched a massive arthropod inventory in Madagascar, collecting spiders, insects and other invertebrates from all over the island.

Wood used those collections, along with specimens from other museums and spiders that she collected during her own field work in Madagascar, to conduct her study. Her detailed observations and measurements of hundreds of specimens led to the identification of 18 new species–but Wood says there are almost certainly more to be discovered. As field workers continue to collect specimens across Madagascar, “I think there’s going to be a lot more species that haven’t yet been described or documented,” she said.

The spiders Wood personally collected, including holotypes (the exemplar specimens) for several of the new species, will join the U.S. National Entomological Collection at the Smithsonian, the second-largest insect collection in the world, where they will be preserved and accessible for further research by scientists across the globe.

All of the pelican spiders that Wood described live only in Madagascar, an island whose tremendous biodiversity is currently threatened by widespread deforestation. The new species add to scientists’ understanding of that biodiversity, and will help Wood investigate how pelican spiders’ unusual traits have evolved and diversified over time. They also highlight the case for conserving what remains of Madagascar’s forests and the biodiversity they contain, she says.

###

Funding for this study was provided by the Danish National Research Foundation and the National Science Foundation.

###

Original source:

Wood HM, Scharff N (2018) A review of the Madagascan pelican spiders of the genera Eriauchenius O. Pickard-Cambridge, 1881 and Madagascarchaea gen. n. (Araneae, Archaeidae). ZooKeys 727: 1-96. https://doi.org/10.3897/zookeys.727.20222

Family of scaffold web spiders increased with ~20% following discovery of 43 new species

Recent study into spider specimens collected from across China, Indonesia, Philippines, Singapore, Thailand, Vietnam and Madagascar over the past 15 years, revealed the striking number of 43 scaffold web spiders that have stayed hidden from science until now. By describing the new species in a paper published in the open access journal ZooKeys, scientists from Sichuan University and the Chinese Academy of Sciences increase the number of a scaffold web spider family (Nesticidae), known from around the world, with about twenty percents.

The studied family of scaffold web spiders is a relatively small group of arachnids, which can be found at almost any locality, apart from Siberia, Central Asia, Northern and Southern Africa and places at high latitude. Prior to the study of Drs Yucheng Lin, Francesco Ballarin and Shuqiang Li, the species counted 245 in total, 12 of which are extinct and known from fossils only. A curious peculiarity in these spiders is their comb of serrated bristles, located on their rear legs, used to pull silk bands for their webs.

Although large-scale taxonomic surveys of scaffold web spiders have long remained scarce, recently the interest towards spider research in China and Southeast Asia has seen a significant rise. Thus, over the last 15 years, Chinese, American and European arachnologists have carried out several surveys, ending up with precious samples. As a result, Dr Yucheng Lin and his team followed with deeper morphological and molecular studies to discover remarkable diversity.

In their work, the researchers have also established a new genus (Speleoticus) for five previously known, but misplaced species, which spend a lot of their time taking shelter in caves.

The majority of scaffold web spiders occur in temperate areas of the Holarctic realm, where the species tend to be medium-sized, long-legged, and prefer cave-like environments. The species found in the tropical and subtropical areas are, on the other hand, usually smaller, with shorter legs, and can be quite often spotted outside, where they crawl in forest litter, on grass, and under stones.

Original source:

Lin Y, Ballarin F, Li S (2016) A survey of the spider family Nesticidae (Arachnida, Araneae) in Asia and Madagascar, with the description of forty-three new species. ZooKeys 627: 1-168. https://doi.org/10.3897/zookeys.627.8629

Single no more: First females of a Madagascan chameleon described with modern technologies

The first females of a scarcely known chameleon species from Northeast Madagascar have been described. Because of lack of genetic data, X-ray micro-computed tomography scans of the chameleon’s head were used for species assignment. Regrettably, the habitats of this and many other chameleon species are highly threatened by the ongoing deforestation in Madagascar. The study is published in the open-access journal Zoosystematics and Evolution.

Chameleons belong to the most popular animals of Madagascar and have been quite intensively studied in the past. However, many new species are still being discovered and described, and several species are only known by a single or a few specimens. Likewise, the chameleon species Calumma vatosoa from northeastern Madagascar was described in 2001 based on a single male. The identity of females of this species has been unclear until now.

Recently, the PhD student David Proetzel of the herpetology section of the Zoologische Staatssammlung Munchen (ZSM), Germany, found specimens of female chameleons in the collection of the Senckenberg Museum, Frankfurt am Main, Germany, that looked similar to Calumma vatosoa. The problem was, how to prove this? The specimens from Frankfurt were collected back in 1933 and therefore, the extraction of DNA for genetic analysis was not possible anymore.

Researchers of the ZSM have been using X-ray micro-computed tomography scans for a few years to study the internal morphology of organisms in a non-invasive way.

“With the help of Micro-CT you can investigate even the skeleton of very valuable samples like holotypes without destroying them,” explains David Proetzel.

“In chameleons the morphology of the skeleton, especially the skull, contains important characteristics that distinguish different species,” explains the researcher. “Here, the comparison of the skulls of the male and the female showed that they belong to the same chameleon species. With the help of modern technology we could describe females of Calumma vatosoa for the first time, and add another distribution locality of this species.”

“The habitats of many chameleon species, and not only, are highly threatened by the ongoing deforestation in Madagascar and we need rapidly to expand our knowledge about the biodiversity, so that suitable conservation measures can be taken,” he stresses.

###

Original source:

Proetzel D, Ruthensteiner B, Glaw F (2016) No longer single! Description of female Calumma vatosoa (Squamata, Chamaeleonidae) including a review of the species and its systematic position. Zoosystematics and Evolution, 92 (1): 13-21. doi: 10.3897/zse.92.6464

A new species and genus of ‘horned necked’ praying mantis from a French museum collection

While studying the insect collection of the Museum national d’Histoire naturelle, Paris, France, two American scientists uncovered a small, leaf-dwelling praying mantis with unique features collected from Madagascar in 2001. Its distinctive “horned neck” and flattened, cone-like eyes, as well as the location from where it was found, led the researchers to assign the insect to a new genus and species. The study is published in the open-access journal ZooKeys.

Lead author Sydney Brannoch and co-author Dr. Gavin Svenson, both of the Cleveland Museum of Natural History and Case Western Reserve University, were working on a research project in their laboratory in Cleveland, Ohio, when Brannoch discovered the undescribed insect among the French collection on loan to them at the time. To determine the insect’s identity, the researchers first investigated the specimen’s locality, Tampolo, Madagascar, where it had been collected from the leaves of an unrecorded tree. When compared to other praying mantis species from this region, they found that this individual had many peculiarities that set it apart.

After comparing and analyzing specimens from various museums, the Cleveland scientists created a new genus for the praying mantis. They selected the genus name Cornucollis to reflect the horn-like projections, which extend from the insect’s neck. The team described and named the new mantis species Cornucollis masoalensis after the locality where the mantis was originally collected. It belongs to the subfamily Tropidomantinae, which is comprised of smaller, usually green mantises that appear to live on broad-leafed plants.

“Identifying a unique praying mantis hidden among other species was unexpected and exciting,” said lead author Sydney Brannoch, a Case Western Reserve University graduate student working under the direction of Dr. Gavin Svenson at the Cleveland Museum of Natural History. “There are untold numbers of species new to science sitting in cabinets and cases within natural history museums around the world. Often these specimens have been overlooked, in some cases for centuries. The discovery of this new praying mantis ultimately highlights the need for continued research in museum collections.”

“Museum collections hold hidden treasures of biodiversity,” said co-author Dr. Gavin Svenson, curator of invertebrate zoology at the Cleveland Museum of Natural History and adjunct assistant professor at Case Western Reserve University. “A closer look can reveal species never before recognized as unique.” Dr. Svenson supported the study as part of his ongoing research to classify praying mantises based on evolutionary relationships.

The newly described leaf-dwelling mantis, Cornucollis masoalensis, measures about 24 millimeters in length, which is small for a praying mantis. It has distinctive speckled patches on its head. The new mantis is pale in color with opaque, well-developed wings. Based on external appearance, the researchers believe that this species dwells on the undersides of leaves, a unique ecological niche occupied by morphologically similar, closely related species.

The scientists suggest further field surveys could provide science with additional knowledge about the new species and genus, including the description of a female individual.

This study was done as part of Dr. Svenson’s broader research project, which is focused on the evolutionary patterns of relationship, distribution, and complex features of praying mantises. His current research project aims to align new sources of relationship evidence (DNA sequence data) with morphology and other features to create a new and accurate classification system for praying mantises that reflects true evolutionary relationships.

###

Original source:

Brannoch SK, Svenson GJ (2016) A new genus and species (Cornucollis gen. n. masoalensis sp. n.) of praying mantis from northern Madagascar (Mantodea, Iridopterygidae, Tropidomantinae). ZooKeys 556: 65-81. doi: 10.3897/zookeys.556.6906

Additional information:

About The Cleveland Museum of Natural History:

The Cleveland Museum of Natural History, incorporated in 1920, is one of the finest institutions of its kind in North America. It is noted for its collections, research, educational programs and exhibits. The collections encompass more than 5 million artifacts and specimens, and research of global significance focuses on 10 natural science disciplines. The Museum conserves biological diversity through the protection of more than 7,300 acres of natural areas. It promotes health education with local programs and distance learning that extends across the globe. Its GreenCityBlueLake Institute is a center of thought and practice for the design of green and sustainable cities. Its website is: http://www.cmnh.org.