Abel Pérez González

Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" · Arachnology Division

Geometric regularity of spider webs has been intensively studied in orb-weaving spiders, although it is not exclusive of orb weavers. Here, we document the geometrically regular, repetitive elements in the webs of the non-orb-weaving groups Leptonetidae and Telemidae for the first time. Similar to orb weavers, we found areas with regularly spaced p...

The evolution of reproductive strategies depends on the relative balance between current benefits and future costs. Geographic variation in demographic and ecological factors has the potential to affect reproductive strategies by altering this optimal cost-benefit balance. Here, we studied a population of the harvestmen Discocyrtus prospicuus inhab...

Recluse or violin spiders in the genus Loxosceles (Scytodoidea: Sicariidae) are a diverse group (~140 extant species) including medically important species and distributed mainly in the Americas, Africa, and the Mediterranean region. In addition, this genus includes three fossil species from Miocene Dominican amber. Here we revise the taxonomy of t...

Brazil’s caves, home to diverse species and minerals, were stripped of protections by a recent presidential decree.

Taxonomic monographs synthesize biodiversity knowledge and document biodiversity change through recent and geological time for a particular organismal group, sometimes also incorporating cultural and place-based knowledge. They are a vehicle through which broader questions about ecological and evolutionary patterns and processes can be generated an...

Triaenonychidae is a family of Opiliones with almost 500 described species distributed in the southern continents. Recent work has provided a solid phylogenetic foundation based on Sanger and ultraconserved element molecular sequence data that resulted in a global reorganisation of the family. In this study, we turn to the South American triaenonyc...

Stenostygnus martensi spec. nov. and Stenostygnus huberi spec. nov. are described from montane localities of the States of Mérida and Lara in Venezuela, and the diagnosis of the previously monotypic genus Stenostygnus Simon, 1879, is emended. The presence of these two new species as local endemics in Andean localities of Venezuela represents a huge...

In its first twenty years of existence Zootaxa has been widely utilized among researchers of Opiliones, mainly those coming from Latin American countries, principally Brazil. During 2003-2020, a total of 141 papers on Opiliones were published in Zootaxa (no papers were published on Opiliones in the first two years, 2001-2002). The journal has great...

Harvestmen (Arachnida: Opiliones) were among the earliest terrestrial arthropods but their unmineralized exoskeletons are scarce and often fragmentary as fossils (Palencia et al. 2019). Consequently, the discovery and interpretations of fossil harvestmen from the early Palaeozoic can have disproportionate effects on the understanding of evolution i...

Psilodercidae contains some 200 known extant species of small spiders that live in tropical rainforests and caves and is mainly restricted to the Oriental biogeographic realm. Interestingly, at least ten different fossil species have been described from inclusions in Late Cretaceous Burmese amber. This suggests the family has been diversifying in t...

Promecostethus unifalculatus Enderlein, 1909, is the only representative of the order Opiliones from the Crozet Islands. The species belongs to the family Triaenonychidae and is biogeographically interesting because it is a candidate for transoceanic dispersal, a very rare event in this ancient family. Despite this significance, P. unifalculatus is...

The Juan Fernández islands (Chile) are a volcanic archipelago, 670 km away from the continent. Arachnids still remain understudied in those islands. We report the first two records of Parabalta reedii (Butler, 1874) (Opiliones, Gonyleptidae) from the Robinson Crusoe Island. One specimen was collected near San Juan Bautista town (in 2011), while a p...

Triaenonychidae Sørensen in L. Koch, 1886 is a large family of Opiliones with ~480 described species broadly distributed across temperate forests in the Southern Hemisphere. However, it remains poorly understood taxonomically, as no comprehensive phylogenetic work has ever been undertaken. In this study we capitalise on samples largely collected by...

Despite extensive taxonomic work on the Neotropical fauna of the spider genus Micrathena Sundevall, for 27 out of 117 (23%) species only the female morphology has been described, and some of the previously hypothesized male-female matches have been proven erroneous. This work provides new insight about sex matching in two species: Micrathena ruschi...

Harvestmen genera with transcontinental distributions are rare but represent very interesting models for evolutionary and biogeographical studies. However, before attempting to understand such distributions, it is crucial to have a good taxonomic foundation of the focal taxa. One of the most disjunct harvestmen genera is Nuncia Loman, 1902 (Triaeno...

Three new species of the six-eyed haplogyne and ecribellate spiders from the genus Ochyrocera Simon, 1891 are illustrated and described based on males and females from southeastern Brazil: Ochyrocera tinocoi new species (Sooretama, Espírito Santo state), Ochyrocera garayae new species (Linhares and Sooretama, Espírito Santo state) and Ochyrocera it...

Who is going to describe our biodiversity?: the taxonomic impediment faced to the Nagoya Protocol and the current regulations. The entry in force of the Nagoya Protocol on access on genetic resources and benefit sharing has triggered, since 2014, national and provincial regulations in Argentina, which rule different activities, among them the colle...

Resumen: Se registran dos casos de canibalismo no sexual en la araña sinantrópica Physocyclus globosus (Taczanowski, 1874), así como la depredación del primer estadio ninfal de la araña Theraphosidae Phormictopus cubensis Chamberlin, 1917, en una localidad urbana del occidente de Cuba. Con este nuevo registro, ahora son tres los enemigos naturales...

IS19035 Accepted 20 June 2019 The laniatorean family Phalangodidae has been largely reduced to a core of Holarctic species, however many taxa were never formally transferred to other families. We examined a group of harvestmen related to Beloniscus Thorell, 1891, from Southeast Asia and determined the nature of the relationships of the "Beloniscu...

La vigencia del Protocolo de Nagoya sobre acceso a los recursos genéticos y participación en los beneficios ha impulsado, desde 2014, normativas nacionales y provinciales en Argentina, que regulan diversas actividades, entre ellas la colecta y el traslado de especímenes con fines científicos. En esta nota analizamos las consecuencias negativas sobr...

La noche del 2 de septiembre de 2018 se inició un trágico incendio que destruyó el histórico edificio que ocupaba el Museo Nacional de Río de Janeiro (MNRJ), nada menos que el palacio São Cristóvão que fuera la antigua morada de la familia imperial brasileña localizada en la Quinta da Boa Vista en pleno corazón de la metrópoli carioca. En lo que fu...

In many species of scorpions (Order Scorpiones) and spiders (Order Araneae), mating plugs (gel-like or sclerotized) are deposited in the female reproductive tract, minimizing the possibilities of further matings. Although harvestmen (Order Opiliones) have direct sperm transfer via copulatory organs (penis or spermatopositor in the male and oviposit...

The Convention on Biological Diversity (CBD) commits its 196 nation parties to conserve biological diversity, use its components sustainably, and share fairly and equitably the benefits from the utilization of genetic resources. The last of these objectives was further codified in the Convention's Nagoya Protocol (NP), which came into effect in 201...

Harvestmen penises are intromittent structures surprisingly complex and diverse, making it difficult to imagine that the sole function of the penis is sperm transfer. Knowledge of penis morphology in harvestmen is largely derived from taxonomic works. Therefore, we have a considerable amount of information regarding genital structures, but relative...

The family Drymusidae includes 16 cryptic spiders that build irregular webs in dark places. The family is distributed in South Africa, the Neotropical and Andean regions. Here, we use a molecular approach to infer the relationships of Drymusidae using three mitochondrial (COI, 16S, 12S) and three nuclear (H3, 28S, 18S) markers. Our preferred analys...

Kimulidae es una de las familias neotropicales de opiliones menos estudiadas en América del Sur. Dos aspectos hacen sospechar la presencia de una biodiversidad altamente subestimada: i) concentración de muchas especies con alto endemismo en una pequeña porción de territorio Venezolano y ii) la gigantesca alopatría de su distribución continental con...

A new troglobitic harvestman, Relictopiolus galadriel gen. nov et sp. nov., is described from Olhos d’Água cave, Itacarambi, Minas Gerais State, Brazil. Morphological characters, including male genitalia and exomorphology, suggest that this species belongs to the family Kimulidae, and it appears to share the greatest similarities with Tegipiolus pa...

Fully-resolved phylogenetic tree obtained by Bayesian inference analysis of the complete concatenated dataset, conducted in MrBayes. Support values at nodes represent posterior probabilities. (PDF)

Chronogram obtained by Bayesian inference analysis of the complete concatenated dataset including COI and H3 third codon positions, conducted in BEAST. Support values at nodes represent posterior probabilities and blue bars represent the 95% Highest Posterior Densities around divergence time estimates. (PDF)

Chronogram obtained by Bayesian inference analysis of the complete concatenated dataset, conducted in BEAST. Support values at nodes represent posterior probabilities and blue bars represent the 95% Highest Posterior Densities around divergence time estimates. (PDF)

Fully-resolved phylogenetic tree obtained by Bayesian inference analysis of the complete concatenated dataset including COI and H3 third codon positions, conducted in MrBayes. Support values at nodes represent posterior probabilities. (PDF)

La presente obra ofrece un compendio de métodos para el inventario y el monitoreo de diferentes grupos de la biota terrestre en Cuba. Realizada con la colaboración de 71 especialistas, fue escrita fundamentalmente para estudiantes, biólogos de campo, profesionales y técnicos de la conservación, que desarrollen trabajos relacionados con las ciencias...

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009;...

This plot is not part of the published stance but derives from it. The plot shows the number of authors by geographic region (courtesy of Dr. Diego Astua).

Cavernicolous species that exhibit a high degree of troglomorphism often provide some of the most intriguing evolutionary riddles. For such taxa, the correct systematic arrangement is difficult to determine and becomes problematic when based solely on highly convergent external morphological characters, leading to exaggerated support of spurious re...

Background There has never been any published work about the diversity of spiders in the city of Rio de Janeiro using analytical tools to measure diversity. The only available records for spider communities in nearby areas indicate 308 species in the National Park of Tijuca and 159 species in Marapendi Municipal Park. These numbers are based on a...

Estimates

Most Abundant Species at Pedra Branca State Park

The type specimens of Fijicolana tuberculata Roewer, 1963 were re-examined and the male genital morphology is illustrated and described for the first time. Despite the presence of several morphological features that are typical of Samoidae, such as the presence of scopulae on legs III and IV, genital morphology unambiguously indicates that this spe...

Background: A series of databases is being prepared to list the valid species of Opiliones worldwide. This paper containing nomenclatural acts is meant to accompany Part 2, which includes the members of the infraorder Grassatores of the superfamilies Samooidea and Zalmoxoidea plus the Grassatores currently not allocated to any family (i.e. Grassat...

Including more than 6500 species, Opiliones is the third most diverse order of Arachnida, after the megadiverse Acari and Araneae. This database is part 2 of 12 of a project containing an intended worldwide checklist of species and subspecies of Opiliones, and it includes the members of the suborder Laniatores, infraorder Grassatores of the superfa...

World Checklist of Opiliones species (Arachnida). Part 2: Laniatores – Samooidea, Zalmoxoidea and Grassatores incertae sedis

Acropsopilio chilensis Silvestri, 1904 (Eupnoi: Caddidae: Acropsopilioninae), is recorded for Robinson Crusoe Island, Chile. This is the first harvestman species recorded for the Juan Fernández Archipelago and also the first extra-continental record for this species. During the comparison with continental co-specific specimens, some previously unkn...

We describe the previously unknown male of Litoporus iguassuensis Mello-Leitão, 1918 and document the exceptional biology of this species: (1) females and juveniles but not adult males construct camouflaged retreats; (2) there is a strong sexual dimorphism involving coloration, leg length, and behavior; (3) females at some localities are color poly...

Incorporating masculine genitalic characters into Opiliones taxonomy has produced important revisions in the systematics of this group of arachnids. Currently, the inclusion of penis morphology in the description of any taxon of Phalangida (harvestmen with penis: Eupnoi + Dyspnoi + Laniatores, as used in Pinto-da-Rocha et al. 2007) has become an al...

The internal phylogeny of the arachnid order Opiliones is investigated by including molecular data from five molecular markers for ca. 140 species totalling 43 families of Opiliones. The phylogenetic analyses consisted of a direct optimization (DO) approach using POY v. 4 and sophisticated tree search algorithms as well as a static alignment analys...

The Tocantins 2007 Expedition of the Project “Aracnídeos e Miriápodes da Mata Atlântica” (AMMA)produced many new records of arachnids and centipedes, with 61 morphotypes identified. Among the resultsare: OPILIONES: 30 morphotypes with six new records of families and one of subfamily from Tocantinsstate; discovery of two undescribed species of Roque...

Sexually dimorphic glands often release sexual pheromones both in vertebrates and invertebrates. Species of Laniatores (Arachnida, Opiliones) seem to depend on chemical communication but few studies have addressed this topic. In this study, we review the literature for the Phalangida and present new data for 23 species of Laniatores. In 16 taxa, we...

In the course of conducting a systematic review of the Cuban Stenostygninae (Biantidae), it has been deemed critical to review Heterolacurbs ovalis Roewer, 1912 from Togo. The habitus and the enlarged metatarsus III of males (as shown in Roewer 1912: 185, fig. 42 and 1923: 143, fig. 154) of this species, which is currently placed in the Lacurbsinae...

Kimula cokendolpheri new species is described from the Central Range of the Dominican Republic, West Indies. It is the first non-fossil species of this genus recorded from Hispaniola.

A new spider species, Ochyrocera ibitipoca sp. n., is described from caves in the state of Minas Gerais, Brazil. A close relationship to Ochyrocera viridissima Brignoli, 19742. Brignoli , P. M. 1974. Ragni del Brasile. I. Ochyrocera viridissima n. sp. (Araneae, Ochyroceratidae).. Rev Suisse Zool, 81: 77–81. View all references is indicated by male...

The fifth species of the genus Spinopilar Mello-Leitão 1940 is described. This is the second cavernicolous species of the subfamily, the other being Pararezendesius luridus H. Soares 1972 from caves in São Paulo State, Brazil. Spinopilar moria, new species, shows elongate appendages, significantly longer than the epigean species of Spinopi-lar, hig...

A new genus of Ideoroncidae, Pseudalbiorix, is described from Central America, and is found to consist of four species: the type species P. reddelli (Muchmore 1982), new combination from southern Mexico, P. veracruzensis (Hoff 1945), new combination from Belize, Guatemala and southern Mexico, and P. muchmorei Barba & Pérez, new species and P. armas...

Two new species of Brazilian Fissiphalliidae are described. Fissiphallius chicoi n. sp. from Pará State, Gurupá municipality, whitewater floodplains (várzea), and Fissiphallius tucupi n. sp. from Amazonas State, Castanho municipality (paleovárzea). The number of species for this family in the Amazon rainforest increases from one to three. The two n...

Two new species of Brazilian Fissiphalliidae are described. Fissiphallius chicoi n. sp. from Pará State, Gurupá municipality, whitewater floodplains (várzea), and Fissiphallius tucupi n. sp. from Amazonas State, Castanho municipality (paleovárzea). The number of species for this family in the Amazon rainforest increases from one to three. The two n...

The genus Leptopholcus has a circumtropical distribution, but the only New World records previously known were for the Greater Antilles. On these islands, Leptopholcus is quite common, probably due to the absence of Metago-nia from the Antilles. On the other hand, Leptopholcus was previously thought to be absent from the mainland where Metagonia is...

A new cosmetid, Arucillus armasi sp. n., is described from the Central Range of the Dominican Republic. This is the second known species for the genus, the other is A. hispaniolicus Šilhavý, 1971. The male of the new species can be easily separated from A. hispaniolicus by the shape of tibia IV, incrassate and with two dorsal apophyses, the presenc...

The new family Icaleptidae is described, based on the new genera Icaleptes and Zalmopsylla. Each of the new genera is based on a single species, Icaleptes malkini n. sp., from northern Colombia and Zalmopsylla platnicki n. sp. from Ecuador. This is the first record of the order Opiliones for the Cesar Department in Colombia. The new family is chara...

The new genus Giupponia is described for the new species Giupponia chagasi from two limestone caves in Serra do Ramalho, Carinhanha, Bahia State, Brazil. This species shows remarkable troglomorphisms, such as complete depigmentation, very elongate appendages, very high tarsal segmentation and complete loss of the ocular structures. This is the firs...