Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact helpdesk@bioone.org with any questions.
The genus Conothele of the trapdoor family Ctenizidae is reported for the first time from India with the description of two new species Conothele varvarti from Similipal Tiger Reserve in Orissa, eastern India and C. vali from Tawang district in Arunachal Pradesh, northeastern India. The genus was previously considered arboreal in habit but the present record reveals that these two species are strictly ground dwelling. Notes on the natural history are provided for both species.
Although all species of the Brachypelma genus are protected under CITES, few studies have been performed on the genetic structure of the populations of these endangered tarantulas. Here we propose, for the first time in spiders, to use ISSR (Inter Simple Sequence Repeat) technique to study the genetic variability of Mexican populations of Brachypelma vagans (Ausserer 1875). We used a nonlethal technique to collect samples from six populations in the Yucatan peninsula and we tested seven ISSR primers. Four of these primers gave fragments (bands) that were sufficiently clear and reproducible to construct a binary matrix and determine genetic variability parameters. We revealed a very high percentage of polymorphism (P = 98.7%) the highest yet reported for tarantula spiders. Our results show that the ISSR-PCR method is promising for intraspecific variation of tarantula spiders.
The genus Trachelas from the Iberian Peninsula is revised. A new species, Trachelas ibericus from Spain, is described from both sexes, and the female of T. validusSimon 1884, an Iberian endemic, is described for the first time. Data are presented for the occurrence of T. canariensisWunderlich 1987 and T. macrochelisWunderlich 1992, formerly considered Canarian endemics, on the Iberian Peninsula. Trachelas praestans (O. Pickard-Cambridge 1911) is synonymized with Creugas gulosus Thorell 1878. Trachelas purusKritscher 1969 is synonymized with T. rayi Simon 1878, and T. flavipes L. Koch 1882 with T. maculatus Thorell 1875. A diagnosis, descriptions, illustrations, distribution data, and a key are presented for the eight presently known Trachelas species of the Mediterranean region. In addition, an update is given on the presence of Cetonana laticeps (Canestrini 1868) in Spain.
Surazomus uarini n. sp. is described and illustrated based on specimens collected by beating on understory vegetation of Amazonian “terra firme” upland rain forests. A new cuticular structure, possibly a gland opening, is described on the female tarsus I and terminal flagellum. A putatively homologous structure is reported from the same body parts in an undescribed species of Rowlandius Reddell and Cokendolpher 1995; Stenochrus portoricensis Chamberlin 1922; Mastigoproctus maximus (Tarnani 1889); and Thelyphonellus amazonicus (Butler 1872); suggesting a new synapomorphy for the clade Uropygi (i.e., Schizomida Thelyphonida).
The scorpion Apistobuthus susanaeLourenço 1998 is redescribed based on new specimens collected from Khoozestan Province, Iran. It is distinct from A. pterygocercusFinnegan 1932 found in the dunes of Rub' al-Khali. The two species cannot be separated by previously used diagnostic characters. Instead, A. susanae is differentiated from A. pterygocercus by new characters, including more robust legs and pedipalps, shorter pectines, stronger carination, and complete fusion of central lateral and posterior median carinae of the carapace.
A new species of Cyphophthalmi (Opiliones) belonging to the Sri Lankan endemic genus Pettalus is described and illustrated. Represented in a recent phylogeny of the family Pettalidae, this species was designated Pettalus cf. brevicauda, but subsequent examination of its morphology and of the type material of P. brevicauda indicates that it is a separate species. Characterization of male genitalia and SEM illustrations are included. Information on other morphospecies recently collected in Sri Lanka indicates that the number of species on the island is higher than previously thought.
Segestria florentina (Rossi 1790) (Segestriidae) displays iridescent green coloration on the paturons of the chelicerae. This was confirmed by reflectance measurements, which gave a spectral peak at 505 nm. Scanning electron microscopy did not identify cuticular surface scales or sculpturing, suggesting that the cause of the iridescence was subsurface. Transmission electron microscopy revealed 86 alternate dark and light layers in the exocuticle, the mean dimensions of which were 126 nm ± 28 nm and 88 nm ± 55 nm respectively. The identity of each layer was initially unclear. However, by using a combination of materials with different refractive indices in calculations of theoretical reflectance spectra, we concluded that they were most likely to be composed of chitin and air, since a peak of 480 nm was obtained, which most closely matched that which was recorded. The function of the green color is not clear, since S. florentina has relatively poor vision and relies predominantly on vibratory and acoustic signals. The study provides useful information relevant to research into the evolution of structural colors in spiders and, more generally, in nature.
Life history theory predicts that the intensity of selection will decline as individuals age; thus, adaptive traits should decrease during post-reproductive stages. To test this prediction, I measured several potential fitness variables in adult female crab spiders [Misumena vatia (Clerck 1757): Thomisidae]: maximum mass before laying, mass after laying, mass at release into hunting site, carapace width, and days since egg-laying upon A) daily rate of loss in mass after egg-laying while guarding a brood and B) daily rate of gain in mass after release into a rich hunting site. These individuals were members of a normally semelparous population guarding their nests without feeding for 1–26 days past egg-laying. Rate of decline in mass of the spiders slowed significantly over time (P < 0.01), and large individuals lost mass relatively faster than smaller ones (P < 0.05), but no other tested variables affected their rate of loss in mass. However, none of the above-noted variables significantly affected their rate of gain in mass after release into the hunting site. None of these individuals likely produced a second brood. The scarcity of relationships among variables measured, especially those following release into the rich hunting site, is consistent with these individuals experiencing little or no direct selection for fitness-enhancing traits subsequent to egg-laying. The exceptions noted for the guarding period probably resulted directly from success at an earlier life stage.
The morphology of the scent glands of Trogulus tricarinatus (Linnaeus 1767) (Trogulidae), a small, soil-dwelling opilionid species, was investigated by means of serial histological semi thin-sections. The glands constitute paired prosomal glandular sacs that open to the body surface via one pore (ozopore) on either side of the body, dorsally adjacent to coxae I. Consistent with the generally recognized organization of scent glands in Opiliones, an anterior non-secretory region of the reservoir could be distinguished from a posterior secretory area, the latter characterized by a thick vacuolated epithelium. However, there are several unusual scent gland features in T. tricarinatus. First, the ozopores are hidden, with each being surrounded by a kind of external secretion atrium formed by a dorso-lateral integumental fold (dorsal limitation), coxa I (ventral limitation), and a wall of projecting cuticular papillae (outer lateral limitation). A horizontal slit (“secondary opening”) between the top of this wall and the dorsal integumental fold is externally visible. Secondly, no fluid, but solid spherical structures that may represent condensed secretion are found in the reservoirs. Thus, the secretion must pass through the external atrium before reaching the outside, perhaps as a gas produced by slow sublimation of solid secretion boli. Scent gland organization in T. tricarinatus, especially the findings of an external atrium around the ozopores, is not consistent with use in chemical defence, as is generally assumed for scent glands of Opiliones, but indicates a possibly non-defensive role.
In orb web spiders that recycle webs and thus minimize the material costs of web relocation, the characteristics of their temporal movement patterns between web sites can be used to examine otherwise hidden costs. Previous studies have shown that one such cost is the extra risk from predation. An unusually long average residence time at web sites is one indicator of cost. In some cases the pattern of movements also appears to be indicative of high costs, similar to those experienced by spiders that do not recycle web proteins. Nocturnal Poltys noblei Smith 2006 (Araneidae) spiders are heavily reliant on good camouflage in their exposed daytime hiding positions. Thus the risk of moving to an unknown site where the spider may not match its background may impose a large cost on relocation. The temporal pattern and frequency of relocations of P. noblei in northern Sydney are compared to those reported for other orb web species. Poltys noblei, on average, is found to have a long residence period, and the pattern of movement of larger individuals in this species is found to be random. These data support the idea that moving is costly for this species. Finally, the seasonal timing of movements is examined for P. noblei. It is found that most spiders relocate in spring but it is unknown if this is to seek a better web site or for the spider to avoid predation.
The ability of Grammostola. mollicoma (Ausserer 1875) spiderlings (Araneae, Theraphosidae) to emerge from the cocoon without the assistance of their mother was tested experimentally. We created two experimental groups with 23 cocoons in each group. In one of the groups we cut the cocoon wall creating an opening; in the other group, the cocoon remained untouched. We found no differences between the groups in either the number or instar composition of the spiderlings that emerged. The spiderlings were able to emerge without the assistance of their mother. The emerging instars in both groups were precocious compared to previous suggestions in the literature.
Prey are able to show adaptive antipredator responses in the presence of silk from the wolf spider Hogna helluo (Walckenaer 1837). Hogna helluo also is attracted to chemical cues associated with previously consumed prey. Consequently H. helluo may benefit by modifying its silk deposition when encountering prey cues to avoid detection. Silk is an important medium for female wolf spiders to attract prospective mates, whereas silk is putatively less important for males to attract females. Females also consume much more food than males after maturity; therefore, male and female H. helluo may differ in the relative costs and benefits of silk deposition with respect to improved feeding efficiency. We tested whether field-caught male and female Hogna helluo changed silk deposition patterns in the presence of excreta deposited by domestic crickets, Acheta domesticus, (Linnaeus). Hungry male and female H. helluo were allowed to deposit silk for four hours in containers either previously occupied by five crickets for 24 h or devoid of cues (n = 36). We found no significant decrease in silk dragline deposition among males or females in the presence of prey cues; however, female spiders showed a significant decrease in the number of attachment disks produced in the presence of cricket cues whereas males did not. Our results suggest that Hogna helluo do change silk deposition patterns in the presence of crickets, but that these changes are sex-specific.
We address the current taxonomic status of two problematic Eastern Asian species of Oecobius Lucas 1846 and propose nomenclatural changes in view of the information currently available. Oecobius formosensis (Kishida 1943) is considered unrecognizable and proposed as a nomen dubium. Two synanthropic species, Oecobius navus Lucas 1859 and Oecobius concinnusSimon 1893, are newly recorded for Taiwan. Evidence from the literature indicating that a third species (Oecobius marathaus Tikader 1962) also occurs in that country is provided. Oecobius sapporenseSaito 1934 is transferred to the genus Neriene Blackwall 1833 (Linyphiidae) based on its original description and illustrations.
Fourteen specimens of the jumping spider Gambaquezonia itimanaBarrion & Litsinger 1995 were collected in the vicinity of Mt. Makiling and Los Banos, Luzon Island, Philippines. The species was described only from the holotype female. Males are described for the first time, and additional females are documented.
Maternally inherited bacterial endosymbionts such as Wolbachia can potentially have a major impact on the reproduction of their arthropod hosts. Most previous studies have focused on the effects on insects, but recent evidence demonstrates that the endosymbionts Wolbachia, Rickettsia, and Spiroplasma are also common in spiders. Such infections potentially explain observed characteristics of reproduction in this group such as skewed sex ratios or reported cases of parthenogenesis. Here we test spiders and a range of other arachnids for infection with another, more recently described maternally acquired endosymbiont, Cardinium. We present data from a survey of spiders and other arachnids collected in the field and obtained from museum collections. Infections with Cardinium are found to be very widespread, perhaps more so than in other arthropod groups. The consequences of this and directions for future research on endosymbiont-arachnid interactions are discussed.
Whip spiders (Arachnida, Amblypygi) are little-studied arachnids with enlarged spiny pedipalps and elongated “antenniform” forelegs. These antenniform legs contain at least seven giant sensory neurons with no known behavioral function. Here we use high-speed cinematography to describe the prey capture behavior of the whip spider Phrynus marginemaculatus C.L. Koch 1840, in order to examine how these giant neurons might be involved. When presented with a prey item (a cricket), a whip spider first accurately aims one of its antenniform legs in the prey's direction. Next, the whip spider orients its body to the prey item and approaches, placing one antenniform leg tip on either side of the prey. The whip spider may remain relatively still in this position for some time, before opening its pedipalps in preparation for a strike and then rapidly swinging its antenniform legs away from the prey item and striking at it with its pedipalps. In common with previous studies, our results show that giant neuron activity is not necessary to trigger any of the stages of normal prey capture behavior, but they also suggest that these neurons could still provide information important in this context.
We provide a brief report on the feeding behavior of two salticid species in Bijilo Forest, The Gambia: Holcolaetis vellerea Simon 1909 and Menemerus bivittatus (Dufour 1831). The former was observed consuming a giant huntsman spider ?Heteropoda sp. (Sparassidae), which was much larger than itself and represents the first published evidence of araneophagy in this genus. M. bivittatus was frequently observed loitering close to, and orientated towards the nest entrance of stingless bees (Apidae, Apinae, Meliponini), watching them as they entered and left, but no other salticid species were observed doing this. Araneophagy and prey-specific predation behavior are well known in salticids but the behaviors reported here have not previously been documented.
A velvet worm (Peripatus sp., Peripatidae) was observed and photographed while feeding on a theraphosid spider, Hapalopus butantan (Pérez-Miles, 1998). The present note is the first report of an onychophoran feeding on “giant” spider.
In this study, we investigated whether two plesiomorphic zodariid species, Lachesana insensibilisJocqué 1991 and Pax islamita (Simon 1873), both from Israel, possess adaptations for myrmecophagy similar to those of apomorphic zodariid genera. Our analysis focused on the predatory behavior and potential prey of these two spider species. We deduced that P. islamita does not feed on ants in nature since these were not present in its microhabitat. In the habitat of L. insensibilis, however, ants were very abundant, and thus they may serve as an important diet component. In the laboratory, both species were able to subdue a wide variety of prey and therefore should be considered polyphagous. They used a conditional capture strategy. Safe prey was handled by grasping and holding it in a basket-like manner. Dangerous prey such as ants were attacked, released, and finally held in the chelicerae while the spider held its own legs at a safe distance. Both species were able to overcome ants if they were not larger than the spiders. We conclude that both species possess behavioral pre-adaptations for myrmecophagy.
Retreats of orb weaving spiders (Araneidae) were collected during the winter of 2004/2005 in northwestern Germany in order to determine the importance of these animal-made structures as hibernation sites for terrestrial arthropods. Retreats were clipped out of the vegetation, stored, and searched in the laboratory for their inhabitants. Overall, there was a high occupation of retreats by spiders, whereas only a few other arthropods were recorded. For Central Europe, there is no evidence that retreats made by orb weavers support the hibernation of a large spectrum of arthropods other than spiders. Only for spiders that may also occur as secondary occupants, retreats play an important role as hibernation sites.
This article is only available to subscribers. It is not available for individual sale.
Access to the requested content is limited to institutions that have
purchased or subscribe to this BioOne eBook Collection. You are receiving
this notice because your organization may not have this eBook access.*
*Shibboleth/Open Athens users-please
sign in
to access your institution's subscriptions.
Additional information about institution subscriptions can be foundhere