Correlation between spermathecal morphology and mating systems in spiders

This study tested predictions regarding male mating preferences which were based on some aspects of female reproductive morphology which may influence sperm precedence patterns in six species of spiders. Males of two species, whose 'conduit' spermathecal design has been associated in previous studies with first male sperm precedence, showed the predicted preference for associating with immature females about to moult to maturity rather than mature females. Those of a third species, however, associated indiscriminately with mature and penultimate instar females. As predicted, males of three other species with 'cul-de-sac' spermathecal morphology did not associate preferentially with immature females. Immature females were avoided in two of the species, but not in the third. One of the species with cul-de-sac spermathecae showed, as predicted, lack of a strong first male advantage in sperm precedence. These data give only limited confirmation of the predictions.     

Contamination of public facilities with Dermatophagoides mites (Acari: Phyroglyphidae) in Japan

The distribution of allergenic mites, Dermatophagoides farinae and Dermatophagoides pteronyssinus, was surveyed among public facilities in Japan, in order to assess the risk of people, including allergic patients, being exposed to mite allergens outside homes. Dust samples were collected using a vacuum cleaner from bedclothes, floors and other materials in four hospitals, two hotels, two ryokans, one film theatre and four office buildings. Fine dust fractions of these samples were examined for mite antigens by enzyme-linked immunosorbent assay. Overall, clinically important antigen levels of 50 g m–2 (corresponding to approximately 500 mites m–2) or more were detected in 71% of samples from chairs in a film theatre and 42% of samples from tatami and carpet floors of ryokans, whereas such serious mite contamination was not observed in samples from hospitals, hotels and offices. High mean antigen levels were observed in chairs in a film theatre (98.2 g m–2) and floors of ryokans (81.4 g m–2), whereas samples from other facilities showed mean antigen levels of <11 g m–2. Hospitals had individual antigen levels of 50 g m–2 in 2% of mattresses and 5% of painted and tiled floors but not in comforters, futons and pillows. No samples obtained from bedclothes in hotels and ryokans had antigen levels of 50 g m–2. In office buildings where the air was fully controlled by a central air-conditioning system all the year round, 99% of samples showed low antigen levels of <10 g m–2. © Rapid Science Ltd. 1998     

Description of a new pseudoscorpion species of the genus Amblyolpium Simon (Pseudoscorpiones: Garypinidae) from north-western Iran

A new species of pseudoscorpion, Amblyolpium atropatesi n. sp. is described and illustrated on the basis of the adult specimens extracted from soil by Berlese funnel.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:0150B850-E80D-46F5-983C-7E958FE69B87     

Comparative morphology of cheliceral muscles using high-resolution X-ray microcomputed-tomography in palpimanoid spiders (Araneae,Palpimanoidea)

Spiders are important predators in terrestrial ecosystems, yet we know very little about the principal feeding structures of spiders, the chelicerae, which are functionally equivalent to “jaws” or “mandibles” and are an extremely important aspect of spider biology. In particular, members of Palpimanoidea have evolved highly unusual cheliceral morphologies and functions, including high-speed, ballistic movements in mecysmaucheniid spiders, the fastest arachnid movements known thus far, and the elongated, highly maneuverable chelicerae of archaeids that use an attack-at-a-distance strategy. Here, using micro-Computed-Tomography scanning techniques, we perform a comparative study to examine cheliceral muscle morphology in six different spider specimens representing five palpimanoid families. We provide a hypothesis for homology in palpimanoid cheliceral muscles and then compare and contrast these findings with previous studies on other non-palpimanoid spiders. We document and discuss two sets of cheliceral muscles in palpimanoids that have not been previously observed in other spiders or which may represent a position shift compared to other spiders. In the palpimanoids, Palpimanus sp., Huttonia sp., and Colopea sp. showed similar cheliceral muscle anatomy. In Eriauchenius ranavalona, which has highly maneuverable chelicerae, some of the muscles have a more horizontal orientation, and there is a greater degree of cheliceral muscle divergence. In Zearchaea sp. and Aotearoa magna, some muscles have also shifted to a more horizontal orientation, and in Zearchaea sp., a species with a ballistic, high-speed predatory strike, there is a loss of cheliceral muscles. This research is a first step toward understanding cheliceral form and function across spiders.     

TERTIARY NEOTROPICAL HERSILIIDAE (ARTHROPODA, ARANEAE) WITH NEW COMBINATIONS FOR THE EXTANT FAUNA AND COMMENTS ON HISTORICAL BIOGEOGRAPHY OF THE FAMILY

Abstract:  The Neotropical fossil amber Hersiliidae are revised. Prototama Petrunkevitch is a senior synonym of both Priscotama Petrunkevitch and Neotama Baehr and Baehr. Fictotama Petrunkevitch and Perturbator Petrunkevitch are removed from synonymy and are considered nomina dubia because the fossils are poorly preserved. The following new combinations are established for the fossil fauna: Prototama antiqua (Petrunkevitch), P. maior (Wunderlich), P. media (Wunderlich), and P. minor (Wunderlich), and for the extant fauna: P. cunhabebe (Rheims and Brescovit), P. forcipata (F. O. P.-Cambridge), P. longimana (Baehr and Baehr), P. mexicana (O. P.-Cambridge), P. obatala (Rheims and Brescovit), P. punctigera (Baehr and Baehr), P. rothorum (Baehr and Baehr) and P. variata (Pocock) (all ex Neotama ). It is predicted that at least one undiscovered, extant Prototama species exists on Hispaniola. Hersiliidae have a diverse fossil record. The presence of Oecobiidae, the sister taxon of the Hersiliidae, in New Jersey and Lebanese ambers predicts a minimum geological age of Early Cretaceous for the family. Fossils are of paramount importance in studies of historical biogeography but were not considered in earlier hypotheses regarding the palaeogeographical origins of the family. Previous conclusions that Hersiliidae originated in Africa are here considered to be speculative and unsupported.     

Almost a spider: a 305-million-year-old fossil arachnid and spider origins

Spiders are an important animal group, with a long history. Details of their origins remain limited, with little knowledge of their stem group, and no insights into the sequence of character acquisition during spider evolution. We describe a new fossil arachnid, Idmonarachne brasieri gen. et sp. nov. from the Late Carboniferous (Stephanian, ca 305–299 Ma) of Montceau-les-Mines, France. It is three-dimensionally preserved within a siderite concretion, allowing both laboratory- and synchrotron-based phase-contrast computed tomography reconstruction. The latter is a first for siderite-hosted fossils and has allowed us to investigate fine anatomical details. Although distinctly spider-like in habitus, this remarkable fossil lacks a key diagnostic character of Araneae: spinnerets on the underside of the opisthosoma. It also lacks a flagelliform telson found in the recently recognized, spider-related, Devonian–Permian Uraraneida. Cladistic analysis resolves our new fossil as sister group to the spiders: the spider stem-group comprises the uraraneids and I. brasieri. While we are unable to demonstrate the presence of spigots in this fossil, the recovered phylogeny suggests the earliest character to evolve on the spider stem-group is the secretion of silk. This would have been followed by the loss of a flagelliform telson, and then the ability to spin silk using spinnerets. This last innovation defines the true spiders, significantly post-dates the origins of silk, and may be a key to the group''s success. The Montceau-les-Mines locality has previously yielded a mesothele spider (with spinnerets). Evidently, Late Palaeozoic spiders lived alongside Palaeozoic arachnid grades which approached the spider condition, but did not express the full suite of crown-group autapomorphies.     

中国广西十万大山八木蛛属一新种(蜘蛛目:跳蛛科)

记述了广西跳蛛一新种：陈氏八木蛛Yaginumanis cheni sp.nov.。模式标本保存于中国科学院动物研究所,量度单位nm。     

The significance of relatedness and gene flow on population genetic structure in the subsocial spider Eresus cinnaberinus (Araneae: Eresidae)

Interdemic selection, inbreeding and highly structured populations have been invoked to explain the evolution of cooperative social behaviour in the otherwise solitary and cannibalistic spiders. The family Eresidae consists of species ranging from solitary and intermediate subsocial to species exhibiting fully cooperative social behaviour. In this study we, in a hierarchical analysis, investigated relatedness of putative family clusters, inbreeding and population genetic structure of the subsocial spider Eresus cinnaberinus. Five hierarchical levels of investigation ranging from large scale genetic structure (distances of 250 and 50 km level 1 and 2) over microgeographic structure (20 km² and 4 km², level 3 and 4) to a single hill transect of 200 m (level 5) were performed. The purpose of level 5 was two-fold: (1) to investigate the relatedness of putative family groups, and (2) to evaluate the influence of both family living and sampling design on higher level estimates. Relatedness estimates of putative family groups showed an average relatedness of R=0.26. There was no indication of inbreeding. In contrast to social spiders, genetic variation was abundant, H_e?0.10. The population genetic structure was intermediate between social and asocial spiders. Genetic variance increased continually across hierarchical levels. Family structured neighbourhoods biased differentiation estimates among level 5 samples (F_ST? 0.04) and level 3 and 4 samples (0.07ST<0.18), and apparent inbreeding among level 3 and 4 samples, F_IS>0, was caused by disjunct sampling from separate neighbourhoods. Larger scale samples were highly differentiated 0.12ST<0.26, depending on level and sampling design. Due to a distance effect family living did not influence estimates of the higher level 1. Although the dispersing sex among social spiders and the subsocial E. cinnebarinus differ, females versus males, female behaviour of both sociality classes lead to high genetic variance.