Tag: spider

New species of marine spider emerges at low tide to remind scientists of Bob Marley

It was 02:00h on 11 January 2009 when the sea along the coastline of Australia’s “Sunshine State” of Queensland receded to such an extent that it exposed a population of water-adapted spiders. The observant researchers who would later describe these spiders as a species new to science, were quick to associate their emergence with reggae legend Bob Marley and his song “High Tide or Low Tide”.

In their paper, published in the open access journal Evolutionary Systematics, the team of Drs. Barbara Baehr, Robert Raven and Danilo Harms, affiliated with Queensland Museum and the University of Hamburg, describe the new Bob Marley’s intertidal spider and also provide new information on two of its previously known, yet understudied, relatives from Samoa and Western Australia.

Unlike the spiders which people are familiar with, the intertidal species, whose representative is Bob Marley’s namesake, are truly marine. They have adapted to the underwater life by hiding in barnacle shells, corals or kelp holdfast during high tide. To breathe, they build air chambers from silk. Once the sea water recedes, though, they are out and about hunting small invertebrates that roam the surfaces of the nearby rocks, corals and plants.

The new species, listed under the scientific name of Desis bobmarleyi, is described based on male and female specimens spotted and collected from brain coral on that night in January.

Both sexes are characterised by predominantly red-brown colours, while their legs are orange-brown and covered with a dense layer of long, thin and dark grey hair-like structures. The females appear to be larger in size with the studied specimen measuring nearly 9 mm, whereas the male was about 6 mm long.

While the exact distribution range of the newly described species remains unknown, it is currently recorded from the intertidal zones of the Great Barrier Reef on the north-eastern coast of Queensland.

“The song ‘High Tide or Low Tide’ promotes love and friendship through all struggles of life,” explain the authors for their curious choice of a name. “It is his music that aided a field trip to Port Douglas in coastal Queensland, Australia, to collect spiders with a highly unique biology.”

Apart from reporting their research, the scientists use their paper to pay tribute to a German naturalist from the late 19th century – Amalie Dietrich, as well as the famous Jamaican singer and songwriter. Both admirable figures, even if representative of very different fields, are seen by the authors as examples of “the adventurous and resilient at heart” human nature in pursuit of freedom and independence.

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Original source:

Baehr BC, Raven R, Harms D (2017) “High Tide or Low Tide”: Desis bobmarleyi sp. n., a new spider from coral reefs in Australia’s Sunshine State and its relative from Sāmoa (Araneae, Desidae, Desis). Evolutionary Systematics 1: 111-120. https://doi.org/10.3897/evolsyst.1.15735

Species conservation profile of a critically endangered endemic for the Azores spider

Subject to continuing population decline due to a number of factors, an exclusively cave-dwelling (troglobitic) spider endemic to the Azores is considered as Critically Endangered according to the IUCN Red List criteria.

To provide a fast output, potentially benefiting the arachnid’s survival, scientists from the IUCN – Spider and Scorpion Specialist Group and the Azorean Biodiversity Group (cE3c) at University of Azores, where the main objective is to perform research that addresses societal challenges in ecology, evolution and the environment, also known as the three E’s from the centre’s name abbreviation, teamed up with colleagues from University of Barcelona, Spain, and the Finnish Museum of Natural History.

Together, they make use of a specialised novel publication type feature, called Species Conservation Profile, created by the open access journal Biodiversity Data Journal, to provide scholarly credit and citation for the IUCN Red List species page, as well as pinpoint the population trends and the reasons behind them.

The studied spider species (scientifically called Turinyphia cavernicola) is a pale creature with long legs, large eyes and a total size of merely 2 mm in length. These spiders never leave their underground habitats, which are strictly humid lava tubes and volcanic pits. There they build sheet webs in small holes and crevices on the walls of the caves.

Not only is the species restricted to a single island within the Azorean archipelago (Portugal), but it is only found in three caves. Furthermore, out of the three, only one of them is home to a sustainable large population. These caves are under severe threat due to pasture intensification, road construction and tourist activities.

Although there is not much information about the species distribution through the years, with the spider having been discovered as recently as in 2008, the authors make the assumption that originally there have been significantly greater populations. Not only have they studied thoroughly another fifteen caves located on the island without finding any individuals, but they have identified increasing anthropogenic impact on the habitat.

“The species original distribution was potentially very large compared with the current,” the scientists explain. “Relatively intensive searches in and around the current caves where the species occurs have failed to find additional subpopulations.”

“The trend of decline is based on the assumption that this species can occur in all these caves and that the absence is due to anthropogenic disturbance on caves during the last 50 years,” they note.

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Original source:

Borges P, Crespo L, Cardoso P (2016) Species conservation profile of the cave spiderTurinyphia cavernicola (Araneae, Linyphiidae) from Terceira Island, Azores, Portugal.Biodiversity Data Journal 4: e10274. doi: 10.3897/BDJ.4.e10274

New species of spider discovered ‘next door’ at the borders of cereal fields in Spain

The image that comes to mind when we think of new species being discovered is that of scientists sampling in remote tropical forests, where humans have barely set foot in. However, new species waiting to be discovered can in fact be very close to us, even if we live in a strongly humanized continent like Europe.

Scientists Eduardo Morano, University of Castilla-La Mancha, and Dr Raul Bonal, University of Extremadura, have discovered a new species of spider, formally called Cheiracanthium ilicis, in an area which does not match the image of a pristine habitat at all.

The new species was found in a strongly humanized area in central Spain, specifically, in isolated trees at the borders of cereal fields. These trees, mainly Holm oaks (Quercus ilex), are those remaining of the former oak woodlands that once covered the Iberian Peninsula and which have been cleared for centuries.

The systematic sampling revealed the newly discovered spider had a an exclusive preference for Holm Oaks, as all individuals were collected from the trunks and branches of these trees. Therefore, it was named after this tree’s scientific name “ilicis”.

While adults measure about a centimetre in body length, juveniles are smaller and have greenish colouration that mimics new oak shoots.

The mouthparts are proportionally large, as in the case of other species of the genus, like closely related C. mildei. In the case of the latter, the mouthparts are large enough to penetrate human skin, although the effects of the poison appear mild.

From a conservation perspective, the present study puts forward the need to preserve isolated trees in agricultural landscapes. They are not only a refuge to common forest organisms but to novel species yet to be discovered as well.

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Original source:

Morano E, Bonal R (2016) Cheiracanthium ilicis sp. n. (Araneae, Eutichuridae), a novel spider species associated with Holm Oaks (Quercus ilex). ZooKeys 601: 21-39. doi: 10.3897/zookeys.601.8241

New tarantula named after Johnny Cash among 14 spider species found in the United States

A new species of tarantula named after the famous singer-songwriter Johnny Cash is one of fourteen new spiders discovered in the southwestern United States. While these charismatic spiders have captured the attention of people around the world, and have been made famous by Hollywood, little was actually known about them. The new descriptions nearly double the number of species known from the region. Biologists at Auburn University and Millsaps College have described these hairy, large-bodied spiders in the open-access journal ZooKeys.

“We often hear about how new species are being discovered from remote corners of the Earth, but what is remarkable is that these spiders are in our own backyard,” says Dr. Chris Hamilton, lead author of the study. “With the Earth in the midst of a sixth mass extinction, it is astonishing how little we know about our planet’s biodiversity, even for charismatic groups such as tarantulas.”

Tarantulas within the genus Aphonopelma are among the most unique species of spider in the United States. One aspect of this distinctiveness that is particularly intriguing is the extreme size differences that can be found between species. Some species are quite impressive, reaching six inches (15 centimeters) or more in leg span, while others can fit on the face of an American quarter-dollar coin (see Image 1).

Within the United States, Aphonopelma are found in twelve states across the southern third of the country, ranging west of the Mississippi River to California. These spiders are conspicuous during the warmer months when adult males abandon their burrows in search of mates, yet very little was known about these spiders prior to the study. Dr. Hamilton notes that more than fifty different species of tarantulas had been previously reported from the United States, but that many of them were poorly defined and actually belonged to the same species.

To gain a better understanding of the diversity and distributions of these spiders, the research team spent more than a decade searching for tarantulas throughout scorching deserts, frigid mountains, and other locations in the American Southwest, sometimes literally in someone’s backyard. They studied nearly 3,000 specimens, undertaking the most comprehensive taxonomic study ever performed on a group of tarantulas.

Because most species of tarantula in the United States are very similar in appearance and cannot be distinguished from each other using anatomical features alone, the research team implemented a modern and “integrative” approach to taxonomy by employing anatomical, behavioural, distributional, and genetic data. Their results indicate there are 29 species in the United States, 14 of which are new to science.

Of the new species, one has been named Aphonopelma johnnycashi after the influential American singer-songwriter Johnny Cash. Dr. Hamilton coined the name because the species is found in California near Folsom Prison (famous for Cash’s song “Folsom Prison Blues”) and because mature males are generally solid black in coloration (paying homage to Cash’s distinctive style of dress where he has been referred to as the “Man in black”) (see Image 2).

While the researchers found that most species are abundant and have relatively large distributions, they also noted that some have highly restricted distributions and may require conservation efforts in the not-so-distant future, as they lose their habitats due to climate change and human encroachment.

“Two of the new species are confined to single mountain ranges in southeastern Arizona, one of the United States’ biodiversity hotspots,” says Brent Hendrixson, a co-author of the study. “These fragile habitats are threatened by increased urbanization, recreation, and climate change. There is also some concern that these spiders will become popular in the pet trade due to their rarity, so we need to consider the impact that collectors may have on populations as well.”

In addition to spider specimens collected by the research team, the study used a tremendous number of specimens gathered from museum collections across the United States, including the Auburn University Museum of Natural History (AUMNH). Project senior author Dr. Jason Bond, director of the AUMNH, notes that studies like these highlight the critical role that museum collections play in understanding our planet’s biodiversity. The AUMNH, located in Auburn, Alabama, possesses the second largest collection of Aphonopelma in the world, behind the American Museum of Natural History in New York.

Tarantulas have gained notoriety for their imposing appearance and perceived threat to humans, but Dr. Hamilton notes that the fear is largely unfounded and that the species in the United States do not readily bite, are not dangerous, and are really just “teddy bears with eight legs”.

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Original source:

Hamilton CA, Hendrixson BE, Bond JE (2016) Taxonomic revision of the tarantula genusAphonopelma Pocock, 1901 (Araneae, Mygalomorphae, Theraphosidae) within the United States.ZooKeys 560: 1-340. doi: 10.3897/zookeys.560.6264

To kill a wolf spider: Further observation of a spider wasp larva growing on its host

Having been attacked, paralysed and implanted with a wasp egg to its belly, a wolf spider carries on with its life fully mobile and active. At least, until it is time for the larva to reach out for its first solid meal at a certain development stage. The present study, conducted by a Brazilian team of scientists, led by PhD student Hebert da Silva Souza, Universidade Estadual de Campinas, Sao Paulo, and published in the open-access Journal of Hymenoptera Research, follows the entire cycle of larval development from the egg laying through the formation of a full-grown wasp.

The herein observed wasp species, called Paracyphononyx scapulatus, belongs to a well-known group of spider parasites, which after laying their eggs on a paralysed spider, let it recover and continue living fully mobile until the larvae are mature. However, little has been known about this curious behaviour of this wasp species in particular, since previous studies have already showed differences between the separate members of the genus.

To observe the whole cycle of the wasp larval development, the researchers caught a recently parasitised wolf spider and placed it in a plastic container.

While the larva grew and fed on the abdominal hemolymph, which is the analog to the blood in backboned creatures, its host did not show any peculiarities in its behaviour and even kept its routine being active at night and resting during the day. This is suggested to be attributed to the need of the larva to keep its host safe from predators, such as ants, which could otherwise eat the dead body.

However, ahead of its fifth and last development stage, the larva was seen to double its size and, in the morning, twenty days after the hatching of the egg, it killed its host and fully consumed it within the next forty-eight hours. Having left its host, the larva began to search for a place within the container to construct a cocoon, which took it sixteen hours. Thirty-two days later, a fully grown female wasp emerged.

In comparison, a relative of the observed spider wasp is known to manipulate its host’s behaviour, making it to enwrap itself and the larva in a cocoon-like silken structure so that it is protected while feeding. Yet, it is not certain whether the observed larva’s growth in captivity is not the reason why it had not induced similar behaviour.

In conclusion, the authors suggest that further investigation of the interaction between the two species could provide more information about the evolution of this kind of parasitism, which is likely to have developed independently among the wasp groups.

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Original source:

Souza HS, Messas YF, Masago F, dos Santos ED, Vasconcellos-Neto J (2015) Paracyphononyx scapulatus (Hymenoptera, Pompilidae), a koinobiont ectoparasitoid of Trochosa sp. (Araneae, Lycosidae). Journal of Hymenoptera Research 46: 165-172. doi: 10.3897/JHR.46.5833

The first long-haired ones: New wasp group proposed for 5 new species from India

Long accustomed to parasitising spider eggs, a large worldwide genus of wasps has as few as 24 known representatives in India. However, Dr. Veenakumari, ICAR-National Bureau of Agricultural Insect Resources, and her team have recently discovered five new species of these interesting wasps from different parts of the country. Because of their uniqueness and their strong resemblance to each other, as well to aid taxonomic studies they have been considered as constituting a group of their own. The discoveries and the suggestion of ‘the first long-haired ones’ species group are available in the open-access journal Deutsche Entomologische Zeitschrift.

Among the unique features that bring together the new five species, discovered by Drs. Veenakumari Kamalanathan, Prashanth Mohanraj and F. R. Khan, are the long hair-like structures along the margins of both of their wings. This is also the reason behind the authors’ choice of naming the proposed group adikeshavus, meaning ‘first one to have long hairs’ in Sanskrit.

Within this parasitic superfamily of wasps each group has been long accustomed to a specific host. The tribe to which the new five wasp species belong, for instance, is characterised by its exclusive preference for spider eggs. Parallel evolution accounts for the tiny wings of these wasps which allows them to slip through the silk strands of the egg sacs which are deposited in leaf litter by the spiders. Furthermore, all these species have a uniform length of 1 to 2 mm as a result of their getting used to parasitising relatively medium-sized spider eggs.

With over a thousand species supposed to exist in this genus the scientists suggest that their clustering into groups is a necessity to facilitate future studies.

The authors conclude that it is highly likely that this group of wasps will yield a much larger number of species of parasitoids attacking spider eggs in India.

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Original source:

Kamalanathan V, Mohanraj P, Khan FR (2015) ‘The adikeshavus-group’: A new species group of Idris Förster (Hymenoptera, Platygastridae) from India, with descriptions of five new species. Deutsche Entomologische Zeitschrift 62(2): 247-260. doi: 10.3897/dez.62.6219