Sexual dimorphism in chelicerae,forelegs and palpal traits in two burrowing wolf spiders (Araneae: Lycosidae) with sex-role reversal

Allocosa alticeps and Allocosa brasiliensis are two sex-role-reversed spiders. Females locate males and initiate courtship. Copulation occurs inside male burrows and after copulation the males deliver their burrows to the females. We explored the occurrence of differences in morphological traits related to sex roles in both Allocosa species and compared the results with two non-burrowing wolf spiders with typical sex roles. We measured the length of the foreleg's tibia-patella and the chelicerae. Scanning electron micrographs of palpal tarsus distal sections were taken. Males showed higher values than females in all the traits considered. Adult and penultimate males lacked true claws compared with juveniles and females, but showed modified spines. The palpal organ was more proximal to the tibia compared with the non-burrowing lycosids considered in this study. Spines and palpal organ location could be associated with more effective digging. We discuss how natural and sexual selection could interact on morphology in this scenario.     

Notice

Illustrated keys are given for the identification of larval stages of five species of north-east Atlantic Palaemoninae: Palaemon adspersus, P. elegans, P. longirostris, P. serratus and Palaemonetes varians. Larval diagnoses for the subfamily and for early stages are also included. Recent developments in the functional morphology of larval palaemonids especially eyes, swimming and ontogenetic processes are reviewed.     

Mating behaviour of Staminodeus vectoris (Coleoptera: Curculionidae), and the value of systematics in behavioural studies

The mating behaviour of Staminodeus vectoris Franz (Curculionidae: Curculioninae: Derelomini) is described and discussed in light of a phylogeny of Staminodeus Franz. At La Selva, Costa Rica, S. vectoris is associated with the staminodes of the inflorescences of Asplundia uncinata Harling and several other species of Cyclanthaceae. The males have a row of 6–10 teeth along the margin of the protibia, whereas the females have a small, curved spine on the frons. The adults arrive in numbers at the inflorescences during the pistillate phase of the anthesis of A. uncinata, feeding on the staminodes. Eventually, a female detaches a staminode with her mandibles, falls to the ground, and transports it to the site of oviposition in the leaf litter. First, she crawls underneath the staminode, then moves it posteriorly with her legs, and finally returns to its distal end before repeating the process. The female turns on her back and maintains her original position during the movement of the staminode, using her frontal spine as a point of resistance against the substrate. Meanwhile, a male associates with the staminode. The males fight with their prothoracic legs, executing fast blows until their protibial teeth cling and dislodge competitors from the staminode. The positive and negative allometries of the lengths of the male protibia and female spine, are consistent with their functions in the contexts of sexual and natural selection, respectively. The phylogeny of all seven species of Staminodeus hypothesises that female transporting behaviour evolved before male fighting behaviour.     

Reproductive patterns of Trachycephalus venulosus (Laurenti, 1768) and Scinax fuscovarius (Lutz, 1925) from the Cerrado,Central Brazil

Animal mating systems are moulded by ecological factors, mainly the temporal patterns of reproduction. We report the reproductive period, use of microhabitats, clutch and egg sizes, reproductive efforts, occurrence of sexual size dimorphism, and the relation between body size and fecundity in the gravid females of Trachycephalus venulosus and Scinax fuscovarius at Serra da Bodoquena, Central Brazil. The reproduction of both species was correlated with the rainy season. Females of T. venulosus produced more eggs and their eggs were larger than those of S. fuscovarius. The females of both species were larger and heavier than males. The reproductive effort was measured as the ratio of gonad mass in relation to body mass. Females of both species presented similar reproductive efforts, but males of S. fuscovarius invested more in gonads compared to males of T. venulosus. Trachycephalus venulosus presented significant correlation between snout–vent length versus number of mature eggs and body mass versus number of mature eggs and ovarian mass. Scinax fuscovarius showed significant correlation between body mass versus ovarian mass. Trachycephalus venulosus is an explosive breeder, whereas S. fuscovarius has prolonged reproduction. These species are able to adapt to several types of habitat, due to behavioural and physiological plasticity.     

北朝性爱观念开放论析

性爱是人类社会生活的重要内容。北朝时期的性爱观念是开放的,多妻、再婚、婚外性爱、同性恋等现象的大量存在即是证明。北朝时期开放的性爱观念对人性的张扬解放、社会的发展演进均具有进步意义。     

论嫖宿幼女罪之存废

嫖宿幼女罪的存废学界一直存在争议。"废除论"指出,嫖宿幼女罪是对奸淫幼女的强奸罪的竞合,其违反刑法原则与刑法理论,在司法事务上也造成许多困难等等。"存续论"认为,嫖宿幼女罪就是奸淫幼女的强奸罪,属于特别法与一般法的关系,其保护法益独特、设置合理,且散见于各国刑事立法之中。其实"折中论"更为合理,应重新定义"卖淫儿童",把握同意年龄线,并以性犯罪体系构建为视角考察嫖宿幼女罪。     

Structural origin of sexual dichromatic coloration and luster in the beetle Goliathus cacicus

In the beetle Goliathus cacicus, male elytra show silky luster with iridescence while female ones appear lusterless white without iridescence to our perception. We revealed by structural characterizations and optical measurements that elytral coloration and luster of both male and female beetles stem from the tubular scales on the elytra, whose interior is filled with a random structure. Distinct differences between male and female scales reside in the cortex thickness and the filling fraction of the random structure, which are important factors in the determination of the sexual dichromatic luster and iridescence. In additional to reflection peaks in the visible range, spectral measurements indicate that both male and female elytra display also strong iridescent ultraviolet (UV) reflections. Scattering spectra show that both male and female elytra display UV luster, although it is absent for female ones in the visible range.     

大学生性观念和性心理的调查研究

１９９３年对广州某大学的１０９３名文学、理工、经济和医学专业的本科学生的性观仿和性心理进行问卷调查，调查项目的应答率为９９．３％。半数左右的学生赞成谈论与性有关的问题和认为对性的态度可反映一个人的道德水平。多数大学生不支持婚外性生活和通过性接触来选择自己的伴侣，１／４的学生承认生活已出现受情和近１／１０的未婚学生曾有性生活检验。第一次性生活的年龄有超前趋势，学生中认为自己“就生理、心理或社会意义来     

Developmental genes as a potential tool in population ecology of complex animal life cycles?

Many aquatic invertebrates possess complex life cycles, which include a switch from a vegetative to a sexual mode of reproduction. While sexual reproduction is usually linked to slow rates of propagation, vegetative reproduction leads to high rates of clonal propagation and a fast increase in population size. I have attempted to identify developmental genes which are differentially expressed between sexually and vegetatively reproducing individuals. Quantitative assays of the expression of those diagnostic genes could be applied to field samples to gain information on the reproductive status of the sample. Here I outline a general strategy for identifying and testing the usefulness of homeobox genes as candidates for regulatory genes whose expression patterns are indicative of a sexual or vegetative developmental phase.     

朱文小说的性意识与反叛姿态

朱文是“新生代”作家的重要代表人物之一。远离主流社会、传统伦理的性意识与低俗生活的叙事立场，显示了作家对传统的反叛姿态和现实的战斗精神。