Tag: harvestman

From science to literature: New arachnid taxa named after Gabriela Mistral and Pablo Neruda

A taxonomic revision describes 22 new species, with two of the names honoring prominent figures of Chilean culture.

Guest blog post by Willians Porto and Abel Pérez González

The third-largest group of arachnids, in terms of number of known species, is the harvestmen, with nearly 7,000 described species, ranking just behind spiders and mites. Despite this number, a considerable portion of their diversity is unknown, and many species still remain undescribed.

An individual of Fresiax spinulosa in a natural setting. — Fresiax spinulosa. Photo by Abel Pérez-González

The harvestmen of the family Triaenonychidae comprise 404 known species and have a peculiar distribution. They are found in temperate regions of the southern hemisphere, with representatives in Australia, New Zealand, South Africa, Madagascar, and southern South America— a typical temperate Gondwana distribution. In the America continent, the diversity is concentrated in the Southern Cone of South America, mainly in the Chilean Valdivian Forest, where 26 species were previously recorded.

A map of Chile showing the distribution of 16 harvestman species. — Distribution maps for 27 harvestman species in Chile.

A map of Chile showing the distribution of Lautaria ceachei. — Distribution maps for 27 harvestman species in Chile.

In our latest work published in ZooKeys, we present the result of a taxonomic and systematic revision of the South American triaenonychids previously included in the mainly New Zealand genus Nuncia. After examining hundreds of specimens, we redescribed all the four previously known species and described 22 new ones. All these species were included in six genera─one resurrected and five new to science─regarding the genus Nuncia as exclusively to New Zealand. The new systematic arrangement was supported by a comprehensive new phylogenetic analysis based on molecular (UCE + Sanger) data.

An individual of Laftrachia robin in a natural environment. — Laftrachia robin, one of the new species described in the study. Photo by Abel Pérez-González

The proposed phylogenetic hypothesis reveals the relationships between South American Triaenonychidae and their counterparts from the rest of the world, indicating that the diversity of triaenonychids in the Southern Cone is polyphyletic, reflecting an ancient diversification predating the Gondwana breakup.

A brown spider in a natural environment. — A species of the newly described Nerudiella genus. Photo by Abel Pérez-González

A bust of Chilean poet Pablo Neruda. — A bust of Pablo Neruda. Photo by Wally Gobetz under a CC BY-NC-ND 2.0 license

Our work represents the most comprehensive contribution to the taxonomy and systematic of South American triaenonychids, almost doubling the number of previously known species. For naming the new taxa, we select names derived from geography, historical figures, and recognized intellectuals. Since most of the newly discovered fauna is distributed across various regions of Chile, the authors decided to honor two prominent figures of Chilean literature. The poet Gabriela Mistral (1889-1957), Nobel laureate in literature in 1945, was honored with the new genus Mistralia, and Pablo Neruda (1904-1973), Nobel laureate in literature in 1971, was honored with the new genus Nerudiella. In addition to tributes to globally renowned Chilean poets, the new species also include dedications to members of the arachnological scientific community and researchers who collaborated on this work.

The taxonomic revision includes hundreds of images that are extremely important for species identification. These images consist of various optical microscopy, stereomicroscopy, and numerous scanning electron microscopy micrographs.

Scanning electron microscope image showing detailed views of the male genitalia of Mistralia verrucosa. — Scanning electron microscope image showing various detailed views of the male genitalia of Mistralia verrucosa.

This work is one of the products of years of collaboration between the Arachnology Division of the Museo Argentino de Ciencias Naturales Bernardino Rivadavia (MACN) and the Giribet Lab in Harvard University and Museum of Comparative Zoology (MCZ). It also represents a continuation of the collaboration initiated in the 20th century by the late Argentinean arachnologist Emilio Maury (MACN) with the Chilean zoologist Tomás Nicolás Cekalovic (Museo de Zoología de la Universidad de Concepción) and the American Museum of Natural History.

Research article:

Porto W, Derkarabetian S, Giribet G, Pérez-González A (2024) Systematic revision of the South American “Nuncia” (Opiliones, Laniatores, Triaenonychidae). ZooKeys 1207: 1-149. https://doi.org/10.3897/zookeys.1207.120068

Behemoth in Leviathan’s crypt: Second Cryptomaster daddy longlegs species

Suggestively called Cryptomaster, the herein studied daddy longlegs genus, represented until recently by a single species, is not only difficult to find in the mountains of southwest Oregon, but had also stayed understudied for several decades since its establishment in 1969. Inspired by much newer records of the previously known species, called after the notorious Hebrew monster Leviathan, an American team of researchers from University of California Riverside and the San Diego State University, led by Dr. James Starrett, undertook a new search for mysterious endemic harvestmen, which was successfully concluded with the discovery of another beast, Cryptomaster behemoth. Their work is available in the open-access journal ZooKeys.

The Cryptomaster daddy longlegs belong in the largest and incredibly diverse harvestman suborder, called the Laniatores, which are characterized by having relatively short legs and preference for hiding underneath logs, stones and leaf litter in tropical and temperate forests. Typical for many of these well over four thousand species is that they might inhabit very restricted geographic regions and yet be strikingly genetically diverse. This is why when the authors understood about the recently expanded distributional range of the Leviathan’s namesake across different mountain ranges, they did not take long to assume that there could be more species having settled nearby.

Curiously, both Cryptomaster daddy longlegs species showed two forms of their species, a smaller and a larger one, but neither form was genetically different enough to suggest the presence of a separate group. The scientists observed the variation in both males and females from across both species and all their known localities.

Having its localities further increased as a result of the present study, C. leviathan shows surprisingly small genetic distance between its populations. In contrast, its sibling species is so far known to occupy far more restricted range, yet shows considerably more genetic variations.

Bearing the name of the huge notorious Hebrew monster Leviathan, the first member of the harvestman genus has won its name because of its excessive size when compared to its relatives within the family of travunioid daddy longlegs. Following the already established trend, the new species is called Cryptomaster behemoth after another large monster known from the Book of Job.

“This research highlights the importance of short-range endemic arachnids for understanding biodiversity and further reveals mountainous southern Oregon as a hotspot for endemic animal species,” point out the authors in conclusion.

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Original source:

Starrett J, Derkarabetian S, Richart CH, Cabrero A, Hedin M (2016) A new monster from southwest Oregon forests: Cryptomaster behemoth sp. n. (Opiliones, Laniatores, Travunioidea).ZooKeys 555: 11-35.doi: 10.3897/zookeys.555.6274

Smeagol found underground in Brazil: New eyeless and highly modified harvestman species

Called after Tolkien’s character from the “Lord of the Rings” series, a new eyeless harvestman species was found to crawl in a humid cave in southeastern Brazil. Never getting out of its subterranean home, the new daddy longlegs species is the most highly modified representative among its close relatives and only the second one with no eyes living in Brazil. Its introduction to science, made by the Brazilian research team of Dr. Ricardo Pinto-da-Rocha, Instituto de Biociências da Universidade de São Paulo together with Dr. Maria Elina Bichuette and MSc. Rafael Fonseca-ferreira from Universidade Federal de São Carlos (UFSCar), is published in the open-access journal ZooKeys.

While there are cave dwellers that can easily survive above the ground and even regularly go out in order to feed or mate, there are some, such as the new harvestman species, Iandumoema smeagol, that never leave their subterranean habitats. As an adaptation, the new harvestman species is eyeless and has a reduced amount of melanistic pigmentation, which shows through its pale yellowish colours.

The fourteen adult and juvenile individuals, observed by the researchers, were noticed to always stay close to the stream, most often preferring the wet cave walls. While the juveniles appeared quite active, the adults showed a more sedentary behaviour.

Typically for the harvestmen, the new species was found in a cave with organic matter deposits or spots. On one occasion the team observed one of the individuals in such litter, where it was scavenging carcasses of invertebrates.

In conclusion, the authors point out that additional studies on the population biology of the new species are urgent so that an adequate conservation strategy can be assumed. It is probable that its highly restricted distribution along with the deforestation taking place in the cave’s immediate surroundings call for the creation of protected areas.

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Original source:

Pinto-da-Rocha R, Fonseca-Ferreira R, Bichuette ME (2015) A new highly specialized cave harvestman from Brazil and the first blind species of the genus: Iandumoema smeagol sp. n. (Arachnida, Opiliones, Gonyleptidae). ZooKeys 537: 79-95. doi: 10.3897/zookeys.537.6073