太行山区幽灵蛛属一新种记述(蜘蛛目,幽灵蛛科)

记述了太行山区蜘蛛区系研究中发现的幽灵蛛科幽灵蛛属1新种:短突幽灵蛛Pholcus pennatus.sp.nov.模式标本保存在河北大学生命科学学院.文中测量单位mm.     

Phylogeny of pholcid spiders (Araneae: Pholcidae): combined analysis using morphology and molecules

The spider family Pholcidae comprises a large number of mainly tropical, web-weaving spiders, and is among the most diverse and dominant spider groups in the world. The phylogeny of this family has so far been investigated exclusively using morphological data. Here, we present the first molecular data for the family analyzed in a phylogenetic context. Four different gene regions (12S rRNA, 16S rRNA, cytochrome c oxidase subunit I, 28S rRNA) and 45 morphological characters were scored for 31 pholcid and three outgroup taxa. The data were analyzed both for individual genes, combined molecular data, and molecular plus morphological data, using parsimony, maximum likelihood, and Bayesian methods. Some of the phylogenetic hypotheses obtained previously using morphology alone were also supported by our results, like the monophyly of pholcines and of the New World clade. On the other hand, some of the previous hypotheses could be discarded with some confidence (monophyly of holocnemines, the position of Priscula), and still others need further investigation (the position of holocnemines, ninetines, and Metagonia). The data obtained provide an excellent basis for future investigations of phylogenetic patterns both within the family and among spider families.     

Male-specific (Z)-9-tricosene stimulates female mating behaviour in the spider Pholcus beijingensis

Chemical signals play an important role in spider sexual communication, yet the chemistry of spider sex pheromones remains poorly understood. Chemical identification of male-produced pheromone-mediating sexual behaviour in spiders has also, to our knowledge, not been reported before. This study aimed to examine whether chemically mediated strategies are used by males of the spider Pholcus beijingensis for increasing the probability of copulation. Based on data from gas chromatography–mass spectrometry analysis, electroantennography assay and a series of behavioural tests, we verified that (Z)-9-tricosene is a male-specific compound in the spider P. beijingensis. This compound acts as an aphrodisiac: it increases the likelihood that a female will mate. Mate-searching males release (Z)-9-tricosene to stimulate sexual behaviour of conspecific females. In the two-choice assay, however, sexually receptive females show no preference to the chambers containing (Z)-9-tricosene. This indicates that the male pheromone of P. beijingensis is not an attractant per se to the conspecific females. This is, to our knowledge, the first identification of a male-produced aphrodisiac pheromone in spiders.     

Web-invasion and araneophagy by New Zealand and Australian pholcid spiders

Abstract

Pholcus phalangioides, Pholcus ancoralis, and Psilochorus sphaeroides were observed in the field in New Zealand (first species only) and Australia (all three species) to invade the webs of other species. P. phalangioides was observed to feed on spiders in alien webs. Webs of each species were frequently contiguous with webs of other spiders and P. sphaeroides sometimes invaded neighbouring webs in pursuit of insects.     

中国幽灵蛛属两新种记述(蜘蛛目:幽灵蛛科)

记述了幽灵蛛科幽灵蛛属2新种:舌幽灵蛛Pholcus lingulatus sp. nov. 和青城幽灵蛛Pholcus qingchengensis sp. nov..模式标本保存在河北大学生命科学学院.舌幽灵蛛,新种Pholcus lingulatus sp.nov. (图1～8)正模♀,副模2♂♂,2♀♀,吉林省桦甸市苇沙河,1973年8月13日.鉴别特征新种雄性触肢器的钩状突形状近似于Pholcus clavimaculatus Zhu et Song, 1999,但有如下2点不同:1)雄性触肢转节距呈弯指状,2)跗前突具一蛇舌状突起.新种的种名根据雄性触肢器跗前突、前侧突起的形状而拟定.青城幽灵蛛,新种Pholcus qingchengensis sp.nov. (图9～14)正模♂,副模1♂,四川省都江堰市青城山,1975年10月26日.鉴别特征新种雄性触肢器的钩状突形状近似于关氏幽灵蛛Pholcus guani Song et Ren, 1994,但有如下3点不同:1)雄性触肢转节距呈铲状,2)跗前突具一钉状突起,3)螯肢前面中部具2个突起.新种的种名根据模式标本的采集地而拟定.     

苍白拟幽灵蛛记述(蜘蛛目:幽灵蛛科)

描述苍白拟幽灵蛛Smeringopus pullidus (Blackwall,1858)雄蛛。     

Spermatozoa and spermiogenesis of Holocnemus pluchei (Scopoli, 1763) (Pholcidae, Araneae)

Until now, the knowledge on pholcid spermatozoa is based on two species, Pholcus phalangioides and, incompletely, Holocnemus pluchei. To complete this knowledge and to reveal more potential phylogenetic characters, we have investigated sperm ultrastructure and spermiogenesis of H. pluchei. We found that the sperm cells of this species are clearly different from those of P. phalangioides with respect to: (1) the lack of specialization in the cylindrical acrosomal vacuole; (2) a nuclear canal which is located in the periphery and not in the center of the nucleus; (3) a more prominent postcentriolar elongation of the nucleus; (4) the presence of "inner microtubules" in the implantation fossa in early and mid-spermatids; (5) the absence of a helical band of nuclear material; (6) the proximal centriole which is not prolonged; (7) the types of secretion in the seminal fluid (only two types in H. pluchei). Similarities in the spermatozoa of both species concern: (1) a large implantation fossa which contains large amounts of glycogen in mature spermatozoa; (2) absence of a centriolar adjunct; (3) an axonemal basis located in the posterior part of the implantation fossa; (4) the formation of the so-called cleistospermia in the vas deferens. Our results strongly support systematic relationships within Pholcidae placing these two species in different subgroups.     

Colonization and diversification of the spider genus Pholcus Walckenaer, 1805 (Araneae, Pholcidae) in the Macaronesian archipelagos: evidence for long-term occupancy yet rapid recent speciation

Macaronesian archipelagos stand apart from other oceanic islands reputed as laboratories for the study of evolution by their proximity to the mainland, lack of subsidence, and steep ecological gradients. The genus Pholcus Walckenaer, 1805, commonly known as daddy-long-leg spiders, is one of the most speciose arthropod groups in the region, with 25 endemic species. In the present study, we use information from four mitochondrial genes, along with morphological data, to examine the phylogenetic relationships and diversification patterns of the genus in the region. Phylogenetic analyses support monophyly of Macaronesian Pholcus including the Moroccan species Pholcus vachoni and hence a single colonization event in the archipelagos. Madeira colonizers most likely originated from the Canaries, and a back-colonization of the nearby mainland receives further support. Estimated lineage divergence times suggest a long-time presence of Pholcus in the region, but also reveal that most present-day species are the result of recent, and probably rapid, speciation events. Diagnostic characters among Macaronesian Pholcus are confined to structures involved in copulation. Coupled with the extremely high diversification rate, the highest recorded for spiders, these copulatory characters suggest that sexual selection has played a key role in the local diversification of Pholcus in Macaronesia.     

Cryptic female exaggeration: the asymmetric female internal genitalia of Kaliana yuruani (Araneae: Pholcidae)

Males of the Venezuelan pholcid spider Kaliana yuruani have unique genitalia, with the procursi about six times as long as usual in the family. The present article describes the previously unknown female, searching for a morphological correlate in the female genitalia to the male's exaggeration. Reconstruction of histological serial sections reveals an internal female complexity that is unequalled in pholcid spiders. An intricate system of ducts and folds is arranged in an asymmetric way, making this the third known case of genital asymmetry in spiders. The term "cryptic female exaggeration" is used in analogy to cryptic female choice, pointing to the fact that from the outside, the female genitalia do not appear unusual. I propose that cryptic female exaggeration may be relatively common in copulatory structures if male exaggerations need to be evaluated according to the female choice by mechanical fit model. Finally, the evolution of genital asymmetry in spiders is contrasted with that in insects.