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1.
Karyotypes of the genus Lasiochernes (Pseudoscorpiones, Chernetidae) are studied for the first time. The diploid chromosome numbers of males were found to be 2n = 61 in L. pilosus, 2n = 69 in L. siculus and 2n = 73 in L. cretonatus. Karyotypes of all species mainly consist of biarmed chromosomes; the sex chromosome system is XO. Remarkably, the X chromosome displays partial (L. cretonatus), or even total (L. pilosus), negative heteropycnosis during the spermatogonial metaphase. 相似文献
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The mating behavior of the cave pseudoscorpion Maxchernes iporangae Mahnert & Andrade, 1998 (Chernetidae), was studied under laboratory conditions. A total of 24 pairings was observed. Mating was divided into three phases: predeposition (dance), spermatophore deposition and transfer, and posttransfer phase. The mean mating duration was 67.3 min based on 10 observations. Spermatophore morphology is described and consists of a stalk, a drop of fluid, and an -shaped sperm package. Males and females can mate several times in the same reproductive period. However, consecutive mating was not observed between a female and the same or another male. 相似文献
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Karl Meßlinger 《Zoomorphology》1987,107(1):49-57
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. 相似文献
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V. N. Belozerov 《Entomological Review》2013,93(5):634-652
Analysis of available information on the seasonal features of life cycles in pseudoscorpions (Arachnida, Pseudoscorpiones) shows that in the temperate climate of Europe with distinct seasonality, the development of these peculiar arachnids can be either eurychronous (= homodynamic), with a poorly pronounced seasonal arrangement, or stenochronous (= heterodynamic), with a distinct seasonal arrangement. This is similar to some other arachnids, particularly spiders and harvestmen. Eurychronous pseudoscorpions are characterized by the approximately year-round development (quite often with winter activity in the whole or part of the population), an overlapping of consecutive generations, the presence of alternative development with or without the dormant state (at all the postembryonic life cycle stages), lack of brood chamber production by females, and the start of free-living life at the protonymphal stage. Stenochronous pseudoscorpions, on the contrary, possess clearly arranged (usually univoltine) development with overwintering deutonymphs and tritonymphs (more rarely adults), a clear separation of adjacent generations, the production of brood chambers where the regressive protonymphs develop until their molt into deutonymphs, and the start of free-living life at the deutonymphal stage. These two types of life cycles are exemplified by two pseudoscorpions from South England, namely Neobisium muscorum with eurychronous development, and Chthonius orthodactylus with stenochronous, univoltine development (Goddard, 1976). There is no correlation between the taxonomic position and the seasonal characters of life cycles in representatives of Neobisiidae, Chthoniidae, and Chernetidae. There is, instead, a close connection between the eco-physiological state of these arachnids and the type of their gas exchange (continuous, diffusive and non-cyclic in the active state, as opposed to discontinuous, with cyclic emission of CO2 and uptake of O2 in the dormant state). The latter information may be useful for distinguishing different kinds of dormancy (diapause and quiescence) in these arachnids. 相似文献
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The sperm of pseudoscorpions consists of a coiled head (nuclear material), axial filament and an annular mitochondrion, all enclosed within a cyst.
Variations occur in the gross morphology of different pseudoscorpion sperm. These variations are discussed in terms of possible morphological relationships. 相似文献
Variations occur in the gross morphology of different pseudoscorpion sperm. These variations are discussed in terms of possible morphological relationships. 相似文献
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The phylogenetic relationships of the major lineages of the arachnid order Pseudoscorpiones are investigated for the first time using molecular sequence data from two nuclear ribosomal genes and one mitochondrial protein-encoding gene. The data were analyzed using a dynamic homology approach with the new program POY v.4 under parsimony as the optimality criterion. The data show monophyly of Pseudoscorpiones as well as many of its superfamilies (Feaelloidea, Chthonioidea, Cheiridioidea and Sternophoroidea), but not for Neobisiodea or Garypoidea. Cheliferoidea was not monophyletic either due to the position of Neochelanops, which grouped with some garypoids. In all the analyses, Feaelloidea constituted the sister group to all other pseudoscorpions; Chthonioidea is the sister group to the remaining families, which constitute the group Iocheirata sensu Harvey--a clade including pseudoscorpions with venom glands within the pedipalpal fingers. This phylogenetic pattern suggests that venom glands evolved just once within this order of arachnids. 相似文献
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Despite the great biodiversity in the Arachnida, some taxa are still now poorly known, mainly in terms of biology, ecology, and behavior. Pseudoscorpions are small arachnids (2–8 mm) that live in cryptic environments, being in general solitary predators of other invertebrates. The most studied Pseudoscorpion species are those from temperate areas, which revealed that Pseudoscorpiones present some level of sociality based on maternal care. Most developed sociality is seen in tropical species. Here, we reviewed this issue, presented examples of social behavior, and suggested the steps involved in the evolution of permanent sociality in the Neotropical Atemnidae genus, Paratemnoides. We discussed that the extended parental care, division of labor, cooperative breeding and feeding, and the tolerance among members dividing the same share could be considered enough to characterize a true social life, same in invertebrates. 相似文献
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Roberta Engel 《Arthropod Structure & Development》2012,41(3):265-269
The chelicerae, the first pair of appendages in Chelicerata, exhibit morphological and functional variation across arachnid orders. The two-segmented chelicerae of pseudoscorpions serve multiple functions including grooming, courtship, and grasping prey. Scanning electron microscopy was used to investigate structures found on the chelicera; the serrulae interiores and exteriores, grooming organs, were given special attention. Functional analogies were made between the cheliceral structures documented in pseudoscorpions and those found in other arthropods. The novel discovery of vestitural papillae and a patch of elongate papillae on the serrula exterior are reported. The focal taxon for the study is Synsphyronus (Garypidae), an Australasian genus. 相似文献
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Karyotypes of pseudoscorpions (Arachnida, Pseudoscorpiones) are largely unknown. Here we describe for the first time karyotypes of the suborder Epiocheirata, represented by 9 European species of two genera of Chthoniidae, Chthonius and Mundochthonius. Diploid chromosome numbers of males range from 21 to 37. Karyotypes of both genera differ substantially. Acrocentric chromosomes predominate in karyotypes of the genus Chthonius, whereas M. styriacus exhibits a predominance of metacentric chromosomes. These differences suggest that the two genera belong probably to distant branches of the family Chthoniidae. It is proposed that karyotype evolution of the genus Chthonius was characterised by a reduction of chromosome numbers by tandem and centric fusions as well as gradual conversion of acrocentric chromosomes to biarmed ones, mostly by pericentric inversions. A tendency towards reduced chromosome numbers is evident in the subgenus Ephippiochthonius. All species display X0 sex chromosome system that is probably ancestral in pseudoscorpions. The X chromosome exhibits conservative morphology. It is metacentric in all species examined, and in the majority of them, a subterminal secondary constriction was found at one of its arms. In contrast to chthoniids, secondary constriction was not reported on sex chromosomes of other pseudoscorpions. Analysis of prophase I chromosomes in males revealed an achiasmatic mode of meiosis. Findings of the achiasmatic meiosis in both genera, Chthonius and Mundochthonius, indicate that this mode of meiosis might be characteristic of the family Chthoniidae. Amongst arachnids, achiasmatic meiosis has only been described in some scorpions, acariform mites, and spiders. 相似文献
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Two new species of the genus Stenohya Beier, 1967 are described from China: Stenohya pengaesp. n. (male and female; type locality Daming Mountain, Nanning City, Guangxi Zhuang Autonomous Region) and Stenohya huangisp. n. (female; type locality Gushan Mountain, Fuzhou City, Fujian Prov.).The presence of Stenohya pengaesp. n. in the tree crown of Castanopsis fabri represents a new habitat for Neobisiidae. A key and a distribution map of the Chinese Stenohya species are also provided. 相似文献
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Susan J. Goddard 《Oecologia》1979,42(1):91-105
Summary The population metabolism of N. muscorum at a beechwood site in southern England was determined for two separate year periods by two methods; a detailed computer analysis and a best estimate. These methods, which are based on data of biomass, population dynamics, field temperatures, and respiration rates of all life stages with temperature, are compared. The validity of extrapolating laboratory determined basal metabolic rates to field activity is discussed; and the population metabolism of N. muscorum is compared with that reported for other soil and litter invertebrate species, both predatory and non-predatory.The metabolic rates of the adults of a second species of pseudoscorpion found at the beechwood site (Chthonius orthodactylus (Leach)), were determined, and the life cycle and metabolism of this species is compared to N. muscorum. The influence of low environmental temperatures on poikilothermic predators, with reference to life cycle strategies, basal metabolism and geographic distribution, is discussed. 相似文献
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V. N. Belozerov 《Entomological Review》2013,93(8):1050-1072
Solifuges (order Solifugae) and pseudoscorpions (order Pseudoscorpiones) united into the superorder Haplocnemata (Shultz, 2007) are nevertheless characterized by essential differences both in morphological and biological characters. Analysis of available information on the biology and life cycles of these arachnids revealed a clear difference between the daily rhythms of activity: their presence in solifuges and their absence in pseudoscorpions. However, this concerning the seasonal adaptations in the two orders is not simple since they demonstrate not only differences but also a lot of similarities. All the studied solifuges are characterized by the seasonally timed stenochronous (heterodynamic) type of development which is characteristic of species with uni-, bi-, and semi-voltine development (i.e., to life cycles completed within a year, half a year, and several years), as well as to species combining different forms of voltinism. This type of development is not only prevalent in solifuges (as in pseudoscorpions and other arachnids) but appears to be the only one, since no cases of eurychronous (homodynamic) development have been found in solifuges; whereas pseudoscorpions and other arachnids develop both steno- and eurychronously. The initial ontogenetic stages remain in underground shelters (brood burrows in solifuges and brood chambers in pseudoscorpions). The first nymphal stages (I instar nymphs in solifuges, protonymphs in pseudoscorpions) are embryonized; active life outside the brood burrows starts with II instar nymphs in solifuges and with deutonymphs in pseudoscorpions. 相似文献
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S. M. GROZEVA 《Systematic Entomology》1995,20(3):207-216
The karyotype of fourteen species of Berytidae has been investigated (ten of them in this paper). All studied Metacanthinae, except possibly Metatropis , have 2n(♂)= 14 + XY. In three examined genera of Berytinae the karyotypes are dissimilar: in Neides and Apoplymus (Berytinae) the chromosome number is 2n(♂)=14 + XY, as for Metacanthinae. In Berytinus spp. the chromosome number is very high ( B.distinguendus: 2n(♂)=30 + XY; B.clavipes: 2n(♂)=32 + XY: B.minor: 2n(♂)=40 + XY).
The structure of the male reproductive system of eleven species is studied. Apoplymus (Berytinae) has two elongate follicles per testis and two pairs of mesadenial glands (mg). Metacanthinae and Neides (Berytinae) have a single elongate follicle per testis and two pairs of mg. Berytinus spp. differ in a number of characters: follicles are shorter and wider, two in each testis; a paired and an unpaired mg.
The number and position of the abdominal trichobothria of twenty-nine species of Berytidae is discussed.
The ancestral condition of the three examined characters is found in primitive genera of both Berytinae and Metacanthinae. The genus Berytinus shows a derived condition in all of these characters. 相似文献
The structure of the male reproductive system of eleven species is studied. Apoplymus (Berytinae) has two elongate follicles per testis and two pairs of mesadenial glands (mg). Metacanthinae and Neides (Berytinae) have a single elongate follicle per testis and two pairs of mg. Berytinus spp. differ in a number of characters: follicles are shorter and wider, two in each testis; a paired and an unpaired mg.
The number and position of the abdominal trichobothria of twenty-nine species of Berytidae is discussed.
The ancestral condition of the three examined characters is found in primitive genera of both Berytinae and Metacanthinae. The genus Berytinus shows a derived condition in all of these characters. 相似文献
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Following the first records of Chthonius (Ephippiochthonius) boldorii Beier, 1934 in central Europe, a species which was previously assumed to occur exclusively in Mediterranean caves, 116 series (595 specimens) of the cryptic taxa C. (E.) boldorii and C. (E.) fuscimanus Simon, 1900 (Syn. C. (E.) austriacus Beier, 1931) were re-examined. Although multivariate analyses suggest specific separation, there is only one unequivocal character for discrimination: the presence or absence of a single isolated tooth on the moveable finger of the chelicerae. The distributions were found to be largely allopatric, therefore it is concluded that the species rank of the two morphospecies is justified. North of the Alps, an almost vicariant pattern emerged: east of 14° E fuscimanus occurs, west of this line boldorii occurs. The results provide a basis for discussing the relevance of minute morphological differences in pseudoscorpion taxonomy. 相似文献
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Planta - Differences in plasmodesmatal organization and frequency between cells which have and have not undergone wall expansion, were studied in four plant species (Trifolium repens L., Raphanus... 相似文献
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Central nervous projection patterns of trichobothria and other cuticular sensilla in the wandering spider Cupiennius salei (Arachnida,Araneae) 总被引:1,自引:0,他引:1
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. 相似文献
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The genitalia and associated glands of five British species belonging to the family Chthoniidae (Pseudoscorpiones: Arachnida) 总被引:1,自引:0,他引:1
The male and female genitalia of five species representing the genus Chthonius are fundamentally similar in form. However minor differences do occur which are of possible taxonomic significance at both the sub-generic and specific levels. Thus, the two species C. kewi and C. tetrachelatus of the sub-genus Ephippiochthonius have a number of characters in common which differ from those of the remaining three species, C. ischnocheles, C. tenuis and C. orthodactylus of the subgenus Chthonius (s.st). Other genital characters can be used to separate the five species.
Such small differences in the genitalia suggests that spermatophore formation and deposition in the four species C. tenuis, C. tetrachelatus, C. kewi and C. orthodactylus is not different from that of C. ischnocheles (Legg, 1973). What differences that do occur, for example, the thickening of the roof of the medial diverticulcum, size of the males and the pheromone produced by the lateral glands, probably are aids to species isolation. 相似文献
Such small differences in the genitalia suggests that spermatophore formation and deposition in the four species C. tenuis, C. tetrachelatus, C. kewi and C. orthodactylus is not different from that of C. ischnocheles (Legg, 1973). What differences that do occur, for example, the thickening of the roof of the medial diverticulcum, size of the males and the pheromone produced by the lateral glands, probably are aids to species isolation. 相似文献