Fine structure of scorpion trichobothria (Arachnida,Scorpiones)

Summary The fine structure of trichobothria in the scorpions Buthus occitanus (Amoureux, 1789) and Euscorpius carpathicus (Linné, 1767) was investigated by electron microscopy. In both species, cuticular and cellular characteristics are very similar. The articulation of the hair corresponds to that of other arachnid hair sensilla. The receptor endings are excentrically attached to the hair base. They consist of an enveloped S-shaped bundle of seven dendrites in B. occitanus and four in E. carpathicus. Neighbouring outer dendritic segments differ a great deal in diameter and ciliary modification. In B. occitanus, three enveloping cells and several additional secretory cells surround the inner dendritic segments. Structural characteristics are compared to those of other arachnid sensilla and their possible functional significance is discussed.     

中国蝎目名录(蛛形纲:蝎目)

本文根据我国蝎目种类已有的记述,归纳列出5科9属19种和亚种的学名、引证及其地理分布,以供今后研究参考.     

Phylogenetic analysis of the scorpion genus Brachistosternus (Arachnida, Scorpiones, Bothriuridae)

A phylogenetic analysis of the scorpion genus Brachistosternus Pocock (Bothriuridae) is presented. The analysis is based on a data set including 38 of the 41 described species of Brachistosternus plus eight outgroup representatives of seven additional bothriurid genera and one buthid, scored for 116 morphological characters. The cladistic analysis of this matrix under implied weighting results in four most parsimonious trees. The monophyly of genus Brachistosternus is well supported; its subgeneric subdivision is redefined: the subgenera Brachistosternus Pocock and Ministernus Francke are considered valid, whereas Leptosternus Maury is synonymized with Brachistosternus . Illustrations of diagnostic structures are provided. The hemispermatophores of Brachistosternus peruvianus Toledo-Piza and Brachistosternus pegnai Cekalovic are illustrated for the first time. A key to species of Brachistosternus and maps with the distribution of the subgenera and main groups of species are provided.     

Linking scorpion (Arachnida: Scorpiones) assemblage with fragment restoration in the Brazilian Atlantic Forest

Habitat loss due to forest degradation can induce changes in species richness due to variation in species susceptibility to environmental stress. This is particularly important for species with highly specific microhabitats, such as scorpions that inhabit forest habitats. In this study, the richness and abundance of these arachnids were compared between an old-growth (mature) and secondary (65 years under natural restoration) forests. Seasonal influence was also evaluated by comparing diversity between dry and wet seasons. The animals were collected through nocturnal active search using UV lamps and pitfall traps in both areas (old-growth and secondary). Both environments showed similar breast heights of trees, litter depth, litter dry mass, and understory density, indicating a high level of restoration. Scorpion diversity (characterized by Tityus pusillus, T. neglectus, T. brazilae, Bothriurus asper, and Ananteris mauryi) and abundance were not influenced by the different historical usage of both areas. In contrast, the abundance of these arachnids was highly affected by rain regimes, and increased during the dry season. These results suggest that 65 years was a sufficient time period for restoration, making it possible to maintain similar scorpion assemblages in both environments.     

Characters in the book lungs of Scorpiones (Chelicerata,Arachnida) revealed by scanning electron microscopy

The fine structure of the book lungs in 29 species representing ten monophyletic taxa of the Scorpiones (Arachnida) was investigated using scanning electron microscopy (SEM). Scorpion lungs are not homogeneous across the group. Here we describe and score three sets of phylogenetically informative characters: (1) the surface ornament of the lung lamellae, (2) the distal margins of the lamellae and (3) the fine structure of the spiracle margin. Provisional results suggest that reticulation on the surface of the lung lamellae is characteristic of the Buthidae. By contrast, non-buthid scorpions maintain the air space between adjacent lamellae using projecting trabeculae. Typically they are simple struts, but the trabeculae are distally branched in all investigated Scorpionidae, plus at least one species belonging to the Liochelidae. Simple thorns on the lamellar margins probably represent the plesiomorphic condition, while more complex, branched, arcuate morphologies appear to be homoplastic, occurring sporadically in numerous scorpion sub-groups. The tightly packed, hexagonal pillars around the posterior margin of the spiracle support a close relationship between Scorpionidae and Liochelidae, to the exclusion of the Urodacidae.     

Morphology and systematics of anthracomartidae (Arachnida: Trigonotarbida)

Abstract: X‐ray microtomography (XMT) was applied to three species of the extinct arachnid order Trigonotarbida, hosted in siderite nodules from the late Carboniferous British Middle Coal Measures. All three, Cryptomartus hindi ( Pocock, 1911 ), Cleptomartus plautus ( Petrunkevitch, 1949 ) and Maiocercus celticus ( Pocock, 1902 ), belong to the family Anthracomartidae. As well as providing interactive three‐dimensional visualisations of their likely appearance in life, XMT study has resolved new morphological detail, yielding key data about the likely stance and habitus of these early arachnids. Similarities in the form of the carapace, eyes and coxosternal region between anthracomartids and the Devonian genus Palaeocharinus Hirst, 1923 are highlighted. Analogies in limb disposition are drawn between anthracomartids and modern crab spiders (Araneae: Thomisidae), which exhibit sit‐and‐wait style predatory behaviour. Anthracomartids are relatively common fossils at many Coal Measures localities. Although they appear to exhibit limited morphological variation, numerous genera and species have been proposed in the literature, often distinguished from each other on rather trivial characters. From our reconstruction of well‐preserved examples, we have resolved a number of common features likely to be present in a typical anthracomartid. Comparisons to this model suggest that the characters on which many anthracomartid genera are distinguished may be artefacts of preservation. We hence treat Promygale Fri?, 1901 , Brachylycosa Fri?, 1904 , Perneria Fri?, 1904 , Coryphomartus Petrunkevitch, 1945 , Cryptomartus Petrunkevitch, 1945 , Pleomartus Petrunkevitch, 1945 , Cleptomartus Petrunkevitch, 1949 and Oomartus Petrunkevitch, 1953 as junior synonyms of the type genus of the family, Anthracomartus Karsch, 1882 . Only the genera Brachypyge Woodward, 1878 and Maiocercus Pocock, 1911 are additionally retained. Within Anthracomartus, Cleptomartus planus Petrunkevitch, 1949 , Cryptomartus meyeri Guthörl, 1964 , Cleptomartus hangardi Guthörl, 1965 and Cryptomartus rebskei Brauckmann, 1984 are treated as junior synonyms of A. hindi Pocock, 1911 (all syn. nov.). Cleptomartus plautus Petrunkevitch, 1949 and Anthracomartus denuiti Pruvost, 1922 are treated as junior synonyms of A. priesti Pocock, 1911 (both syn. nov.).     

On the scorpion fauna of Egypt,with an identification key (Arachnida: Scorpiones)

The taxonomy and diversity of the scorpion fauna of Egypt was examined based on a large collection from most parts of the country and in view of recent revisionary systematics. We assessed the validity of listed records in light of new taxonomic findings and geographic distribution data and present a new list and an identification key to the scorpion fauna of Egypt consisting of 31 species, 18 of which were collected during this survey. Four species were not accepted for the list because no voucher material was available.     

The book lungs of Scorpiones and Tetrapulmonata (Chelicerata, Arachnida): evidence for homology and a single terrestrialisation event of a common arachnid ancestor

The question of whether Arachnida (Chelicerata) conquered terrestrial habitats only once or several times is controversial. The key group in this respect is the Scorpiones. Several authors claim that they became terrestrial independently of other arachnid lineages. This argumentation uses two lines of evidence. One is that book lungs of scorpions and other arachnids are considered non-homologous because they occur on different segments. The other line is based on fossil evidence which suggests that early scorpions were aquatic, together with a putative sister group relationship between scorpions and the aquatic Eurypterida. To address this problem we undertook a comparative scanning electron microscopical and histological study of the book lungs of scorpions, amblypygids, uropygids, and mesothelid spiders. In addition, we included the book gills of a xiphosuran. We found several detailed similarities in the book lungs shared by all arachnid taxa studied. Based on these findings we conclude that arachnid book lungs are homologous. Furthermore, we suggest that the apomorphic book lungs of arachnids indicate a single terrestrialisation event in the stem lineage leading to Arachnida.     

The evolution of the scrotum: a new hypothesis

The adaptive significance of the scrotum is unresolved after more than 60 years of debate and experimentation. The "training hypothesis" introduced here suggests that testicular descent is a mechanism for improving sperm quality. The hypothesis proposes that: (1) testicular descent decreases blood supply to maturing sperm cells, (2) sperm mitochondria respond to the resulting oxygen stress by enhancing their enzymatic machinery for oxidative metabolism, as do oxygen-stressed muscle cell mitochondria, and (3) the resulting increase in aerobic fitness of sperm cells is advantageous in inter-ejaculate competition. The hypothesis suggests that there is a quantity-quality trade-off in sperm production, where taxa with internal testes produce large volumes of low-quality sperm while taxa with scrotal testes produce smaller volumes of higher-quality sperm.     

Central nervous projection patterns of trichobothria and other cuticular sensilla in the wandering spider Cupiennius salei (Arachnida,Araneae)

Summary Central projections of mechano-and chemoreceptors on the legs and pedipalps of the wandering spider Cupiennius salei were traced by anterograde cobalt fills. The primary afferent fibres from trichobothria, tactile hairs, lyriform organs and contact chemoreceptive hairs enter the leg ganglia and pedipalpal ganglia ventrally. On their way through these ganglia there is very little arborization. The main areas of arborization are in the sensory longitudinal tracts in the suboesophageal nervous mass. The central projections of all mechano-and chemoreceptors examined show somatotopic organization. Sensilla located proximally on the legs are represented in dorsally located sensory longitudinal tracts, whereas those located on distal leg segments enter more ventral tracts. The afferent fibres of receptors of identifical modality on a specific segment of all legs and of the pedipalps overlap in the same tracts. No indication for a tonotopic arrangement of the trichobothrial afferences was found, which might have been associated with the mechanical frequency tuning of the trichobothria known from other experiments. The convergence of the projections of different types of receptors in the sensory longitudinal tracts is considered to be an anatomical basis for their functional interaction in behaviour. Both the convergence of the projections of receptors from the same segment of different legs and the somatotopy are connectivity patterns possibly associated with the orientation of the spiders towards mechanical or chemical cues.     

A new hypothesis for the evolution of biological electron transport

A new hypothesis for the evolution of biological electron transport is presented. According to this hypothesis biological electron transport originated close to the potential of the hydrogen electrode and evolved in various advantageous directions including, when molecular oxygen became available on the Earth, that of the oxygen electrode. This implies stepwise evolution along and across the potential scale. The hypothesis is based mainly on existing information obtained from studies of primary and tertiary structural relationships of proteins. It is hoped to provide a framework for closer understanding of both evolution and mechanisms of cellular oxidation-reduction as well as energy coupling reactions.     

Seasonal effects on cuticular permeability and epicuticular lipid composition inCentruroides sculpturatus ewing 1928 (Scorpiones: Buthidae)

Summary Third larval instar hemolymph of the fruitflyDrosophila hydei did not metabolize juvenile hormone (JH) at all developmental stages. In contrast, prepupal and pupal body fluid showed JH-esterase activity with a maximum at 4 h after puparium formation. In body wall and fat body of all developmental stages investigated, JH-metabolic activity was found. In both tissues JH catabolism was most active in the 120,000g supernatant and pellet. The 800g and 15,000g pellet showed a lower activity. In all subcellular fractions the JH-acid was identified as the predominant metabolite. There is evidence that JH-specific esterases are responsible for ester cleavage in the 120,000g supernatant. During mid and late third larval instar development in both body wall and fat body JH-esterase activity remains relatively constant.     

Morphology and evolution of the cynipoid egg (Hymenoptera)

We describe gross egg morphology and provide the first data on eggshell ultrastructure in cynipoids (Hymenoptera) based on species representing three distinctly different life histories: internal parasitoids of endopterygote larvae, gall inducers and phytophagous inquilines (guests in galls). We then use existing phylogenetic hypotheses to identify putative changes in egg structure associated with evolutionary life-history transitions. We find four major structural changes associated with the shift from parasitoids laying their eggs inside a host larva to gall inducers laying their eggs in or on plants: (1) from a narrow and gradually tapering gross form to a distinct division into a stout body and a long and thin stalk; (2) from a thin to a thick eggshell; (3) from a flexible to a rigid endochorion; and (4) from crystal bundles with shifting orientation in the exochorion to layers of parallel crystal rods. By contrast, we find no major changes in egg structure associated with the transition from gall inducers to inquilines. Comparison between pre- and post-oviposition eggs of one gall inducer and one inquiline suggests that mechanical stress during the passage through the egg canal gives rise to numerous tiny stress fractures in the boundary separating the exo- and endochorion. In one of the gall inducers, Diplolepis rosae , that end of the egg, which is inserted into the plant, has a specialized and apparently porous shell that may permit chemical exchange between the embryo and the plant. Other structures that could facilitate chemical communication with the host plant through the eggshell were, however, not observed in the eggs of gall inhabitants.  © 2003 The Linnean Society of London, Zoological Journal of the Linnean Society , 2003, 139 , 247–260.     

Taxonomic review of Bourguyiinae,cladistic analysis,and a new hypothesis of biogeographic relationships of the Brazilian Atlantic Rainforest (Arachnida: Opiliones,Gonyleptidae)

The subfamily Bourguyiinae Mello‐Leitão, 1923 (Gonyleptidae) is revised, and both phylogenetic and biogeographic hypotheses are proposed. Bourguyiinae is monophyletic, and is the sister group of the remainder of the Gonyleptidae species used for analysis, except for the Metasarcinae, which collectively is the sister group of Metavononoides orientalis Mello‐Leitão, 1923 (Cosmetidae). Bourguyiinae is divided into two genera: Bourguyia (six species) and Asarcus (four species). The genus‐level synonyms proposed here are as follows: Caldasius, Styloleptes, and Stylopisthos are junior synonyms of Bourguyia; Bogdana, Cnemoleptes, and Opisthoplites are junior synonyms of Asarcus. The species synonyms proposed here are as follows: Afranius amarali Mello‐Leitão, 1934 is a junior synonym of Bourguyia albiornata Mello‐Leitão, 1923 ; Drastus hamatus Roewer, 1943 and Styloleptes conspersus Piza, 1943 are junior synonyms of Bourguyia trochanteralis Roewer, 1930 ; Asarcus corallipes Simon, 1879 , Asarcus lutescens Sørensen, 1884 , Asarcus pallidus Mello‐Leitão, 1923 , and Opisthoplites ypsilon Sørensen, 1884 are junior synonyms of Asarcus longipes Kollar in Koch, 1839 ; Asarcus nigriconspersus Soares & Soares, 1945 is a junior synonym of Asarcus ingenuus Melo‐Leitão, 1940. New species described are: Bourguyia bocaina sp. nov. (Serra da Bocaina, São José do Barreiro, São Paulo), Bourguyia vinosa sp. nov. (E.B. Boracéia, Salesópolis, São Paulo), and Asarcus putunaberaba sp. nov. (Parque Nacional do Caparaó, Alto Caparaó, Minas Gerais). Bourguyiinae is endemic to the Atlantic Rainforest in the Brazilian states of Minas Gerais, Rio de Janeiro, São Paulo, and Paraná. Based on the modified data matrix of Pinto‐da‐Rocha et al., we propose a new biogeographical hypothesis for the Atlantic Rainforest. We suggest that Bourguyiinae species were originally distributed from the coastal region of Paraná to the north of Rio de Janeiro and south‐east of Minas Gerais, with subsequent dispersals both to northern and southern areas. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 156 , 319–362.     

Two new harvestmen species (Arachnida: Opiliones) from the Caucasus

Two new harvestmen species of the family Phalangiidae, Rilaena caucasica sp. n. and Rilaena silhavyi sp. n. are diagnosed, illustrated, and described from the Caucasus region. Comparative illustration of the related Rilaena anatolica (Roewer, 1956), R. atrolutea (Roewer, 1915) and R. kelbajarica Snegovaya &; Pkhakadze, 2014 Snegovaya, N. Y., &; Pkhakadze, V. D. (2014): New species of the genus Rilaena (Opiliones, Phalangiidae) from the mount Gyamish, Azerbaijan. Vestnik zoologii, 48, 313–318. doi: 10.2478/vzoo-2014-0037[Crossref] , [Google Scholar] are given.

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