三突伊氏蛛雌蛛不同交配史对雄蛛交配行为的影响

近年来越来越多研究表明,雄性产生精子(精液)也需付出代价。在多次交配的动物中,雄性为获得最大生殖潜力,必须依据配偶的质量策略性地调整每次交配的生殖投入。雄性策略性的生殖投入主要体现在两个方面,一是精子竞争(sperm competition),二是柯立芝效应(Coolidge effect)。目前精子竞争研究主要集中于昆虫类群,而柯立芝效应研究集中于高等脊椎动物,同时验证结果也时常与假说不一致。以多次交配的三突伊氏蛛为材料,以雄蛛交配行为为指标,在蜘蛛类群中探讨和验证雄性精子竞争强度假说和柯立芝效应。设定3个交配组合:2只雄蛛依次与1只雌蛛各交配1次(A组)、2只雄蛛依次与2只雌蛛各交配1次(B组)和1只雄蛛与1只雌蛛交配2次(C组),分析比较3个交配组合的三突伊氏蛛第1次交配和第2次交配在交配潜伏期、交配持续时间和交配回合数方面的差异,比较三突伊氏蛛雌蛛不同交配史对雄蛛交配行为的影响,以此验证雄性精子竞争强度假说和柯立芝效应。研究结果表明A和B组的三突伊氏蛛第2次交配的交配潜伏期和交配持续时间显著长于第1次交配。同时,C组的三突伊氏蛛第1次交配的交配潜伏期和交配持续时间与第2次交配都没有显著差异。同时,A、B和C组的三突伊氏蛛第1次交配的交配回合数与第2次交配都没有显著差异。研究结果支持精子竞争强度假说,而不支持柯立芝效应。     

同种雄性竞争对手的存在对星豹蛛雄蛛求偶和交配行为的影响

越来越多的研究发现,雄性产生精子(精液)也需付出代价。雄性除了依据配偶质量和竞争对手的竞争强度适应性调整生殖投入外,雄性在求偶和交配行为上也相应产生适应性反应,求偶和交配行为具有可塑性。目前雄性求偶和交配行为可塑性研究主要集中于雌性多次交配的类群中,在雌性单次交配的类群中研究甚少。以雌蛛一生只交配一次而雄蛛可多次交配的星豹蛛为研究对象,比较:(1)前一雄性拖丝上信息物质对后续雄蛛求偶和交配行为的影响,(2)雌雄不同性比对雄蛛求偶和交配行为的影响。研究结果表明,星豹蛛前一雄蛛拖丝上的信息物质对后续雄蛛求偶潜伏期、求偶持续时间和交配持续时间都没有显著影响,但前一雄蛛拖丝上的信息物质对后续雄蛛求偶强度有显著抑制作用。同时,性比对星豹蛛雄蛛求偶和交配行为都没有显著影响。可见,星豹蛛雄蛛对同种雄性拖丝上的化学信息可产生求偶行为的适应性调整,而对性比不产生适应性反应。     

星豹蛛求偶和交配行为

以星豹蛛(Pardosa astrigera)为研究对象,在室内对其求偶和交配行为进行了描述。雄蛛"俯卧撑"式动作(push-up)在求偶中具重要作用。交配初期,两侧触肢交替插入;随交配进行,单侧触肢连续插入3~5次后才换另一侧触肢插入,触肢每插入一次,基血囊膨大多次。完整交配一次雄蛛触肢器平均插入次数为29·625。交配前求偶时间、交配持续时间和有效交配时间分别平均为6min、32min25s和11min11s。星豹蛛雄蛛可进行多次交配,而雌蛛一般为单次交配。雌蛛交配状态(是否已经交配)影响其同类相食行为,已交配雌蛛对雄蛛同类相食率显著高于未交配雌蛛对雄蛛同类相食率。     

龙平莱蛛(蜘蛛目,泰莱蛛科)的求偶和交配行为

泰莱蛛科属于简单生殖器类蜘蛛,为洞穴蜘蛛的主要类群.本实验首次在实验室条件下对泰莱蛛科蜘蛛龙平莱蛛Pinelema bailongensis的求偶和交配行为进行描述:雄蛛可与多个雌蛛交配,雌蛛一般为单次交配.一次完整的交配进行2～8次交尾,交尾时间为0.27～5.03 min.求偶行为主要涉及探足、腹震和拍足等动作.     

“观众效应”对动物配偶选择的影响研究进展

动物借助于通讯信号传递信息,信息发送者、接收者和旁观者共同组成动物通讯的信息网络环境。旁观者能够“窃取”并利用未直接发送给它们的信号,其存在影响信息发送者和接收者的通讯行为,这种现象被称为“观众效应”。动物的配偶选择和交配过程多发生于由同种动物所组成的信息网络中。越来越多的证据表明,“观众效应”可影响动物个体的择偶偏好和交配决策,进而影响物种的进化。本文主要从“观众效应”的性别差异、影响因素、功能解释等方面综述了其对动物配偶选择的影响,为揭示“观众效应”对配偶选择的影响及其在物种进化过程中的作用提供了新的思路。     

蒙古花蟹蛛生物学特性及对棉铃虫幼虫捕食作用的初步研究

蒙古花蟹蛛在乌鲁木齐和玛纳斯一年发生一代,以初龄幼蛛越冬,3月底4月初出蛰,8月中旬始见成蛛雌雄比约1∶0.87。交配大都在白天,可多次交配。抗逆性极强,三龄幼蛛耐饥、渴可达80天。在棉田其发生(?)与棉铃虫明显相关,r=0.7969。捕食棉铃虫幼虫的功能反应属Holling Ⅱ型,其捕食率随自身密度的增大而(?)小,m=0.5949。     

雌星豹蛛性信息素的行为学证据

采用星豹蛛(Pardosa astrigera)成熟雄蛛求偶时潜伏时间、静止时间、身体震动和第一墩步足伸展次数等行为参数,利用行为学方法测定了不同性别、日龄和生殖状态的星豹蛛雌蛛释放的拖丝对雄蛛求偶行为的影响。结果表明,雄蛛第一对步足伸展和身体震动等典型求偶行为是进行星豹蛛性信息素生物测定的可靠评价指标。星豹蛛雄蛛能通过拖丝上的性信息素辨别星豹蛛的性别、日龄和生殖状态。雄蛛在成熟3周未交配雌蛛拖丝处理过滤纸上潜伏时间和静止时间都相应最短,在交配未产卵雌蛛、雌亚成蛛和成熟雄蛛拖丝上时间中等,在卵孵化雌蛛拖丝处理滤纸上潜伏时间和静止时间都相应最长。成熟3周未交配雌蛛和交配未产卵雌蛛释放的拖丝都能引起雄蛛第一对步足伸展和身体震动等典型求偶行为,雄蛛对成熟3周未交配雌蛛拖丝典型求偶行为的频率都相应高于交配未产卵雌蛛。卵孵化雌蛛释放的拖丝虽也能引起雄蛛第一对步足伸展行为,但其伸展频率显著降低;而其它拖丝都不能引起雄蛛典型求偶行为。     

布氏田鼠的择偶行为

在实验室通过布氏田鼠对配偶与陌生异性鼠,已交配「刚刚和别的雌（雄）鼠进行交配」和未效配异性鼠,熟悉和陌生异性鼠三种情况下配偶选择的实验研究。结果表明;雌性布氏田鼠对与配偶的造反地要多于陌生雄鼠;虽然对陌生和熟悉雄鼠选择差异不显著,但对陌生鼠的选择强度要高于熟悉雄鼠;同时对已交配和未交配雄鼠的选择地显著差异。     

北京幽灵蛛的繁殖行为

室内用数码摄像机记录北京幽灵蛛(Pholcus beijingensis)的求偶、交配、产卵和孵卵行为,并分析了行为动作系列。拨丝和慢跳在求偶中起着重要的作用。北京幽灵蛛有多次交配的习性,雌蛛第一次交配的持续时间显著长于第二次交配,PPMs动作(pedipalp movements)在交配阶段贯穿始终,铲状的引导器在PPMs动作里会移出雌蛛生殖腔内的竞争者的精液和雌蛛分泌物,反映的是最后一个交配雄蛛的精子优先模式。雌蛛有护卵行为,产卵后用螯肢咬住卵袋直至其孵化。     

视觉能触发沟渠豹蛛雄蛛对雌蛛的求偶行为

以沟渠豹蛛Pardosa laura成熟雄蛛的求偶延迟时间和触肢伸展次数作为参数,观察研究了雄蛛通过视觉与处女雌蛛拖丝单独和共同诱导情况下的求偶反应,发现视觉是触发雄蛛求偶行为的主要信号,而雌蛛的拖丝则不能单独激发雄蛛的求偶行为,表明雄蛛能够通过视觉接受雌蛛的信号。在此基础上,又测定了雄蛛通过视觉接受亚成体雌蛛、处女雌蛛和交配未产卵雌蛛信号时的求偶反应,发现雄蛛对处女雌蛛和交配未产卵雌蛛的求偶动作次数显著多于亚成体雌蛛,表明雄蛛能够通过视觉区分雌蛛是否成熟,但是仅依靠视觉无法判断雌蛛是否已经交配。本实验表明视觉在沟渠豹蛛雄蛛对雌蛛识别过程中起着非常重要的作用,再次证实狼蛛的视觉比较发达。     

Copulation type affects parturition in the guppy

In some animals, females are often compelled to mate with less desirable males due to the males' alternative mating tactics. Male guppies, Poecilia reticulata, exhibit courtship displays and cooperatively copulate with females. However, they also exhibit sneaking behaviors and coercively copulate with females. To examine the consequences of these two mating patterns, we investigated the influence of copulation type, i.e., cooperative or coercive, on parturition and brood size of females. A single female was allowed to freely contact and copulate with a single male only once. Males that cooperatively copulated with females had larger orange spot areas (an important criterion of female mate choice) than males that copulated coercively. Most females that were coerced into copulation did not give birth to offspring within 100 days after mating. The probability of parturition was high when females copulated cooperatively, and when their mates exhibited frequent postcopulatory jerking behavior. However, the results suggest that copulation type did not affect brood size. Brood size was positively influenced by both female body size and male orange spot area. These results suggest that parturient success is low when females are coerced into mating by less desirable males, whereas brood size is independent of copulation type.     

Male Performance and Body Size Affect Female Re-Mating Occurrence in the Orb-Web Spider Leucauge mariana (Araneae, Tetragnathidae)

Females can affect male probabilities of paternity success through behavioural, morphological and/or physiological processes occurring during or after copulation. These processes under female-control include the acceptance or rejection of mating attempts by subsequent males. Leucauge mariana is an orb weaving spider that shows male mate guarding of penultimate females, male–male competition on female webs and copulatory plugs, suggesting a polyandric mating system. The aim of the present study was to ascertain whether male behaviour during courtship and copulation in L. mariana relate with female re-mating decisions. Forty-three virgin females were exposed to up to three males until they mated. In 24 cases, the copulatory plug was absent after mating and females were exposed the next day to up to three other males. Eighteen females accepted a second mating. Relatively larger females were more receptive to second matings and were more likely to copulate if the second male was smaller. Longer duration of female tapping and abdominal bobbing during courtship, and first copulations with less short insertions and more flubs, were associated with increased female acceptance to second matings. The results indicate cryptic female choice on male courtship and copulatory performance and suggest female-control over the determination of male mating success in this spider species.     

Identification of Brain Sites Controlling Female Receptivity in Mosaics of DROSOPHILA MELANOGASTER

We have identified cells in the brain of Drosophila melanogaster that are required to be of female genotype for receptivity to copulation with males. To do this, we determined experimental conditions in which female flies virtually always copulate, then measured the minimum amount of male courtship that is required to stimulate females to indicate their receptivity to copulation. We then observed gynandromorphs with female genitalia to determine whether the sex mosaics elicited at least the minimum amount of courtship and, if so, whether they copulated. By analyzing these gynandromorphs, in which the genotype of external and internal tissues could be ascertained, we were able to identify a group of cells in the dorsal anterior brain that, when bilaterally female, is necessary and sufficient for receptivity to copulation. This group of cells is anatomically distinct from those that are required to be of male genotype for the performance of courtship behaviors.     

Males mate guard in absentia through extended effects of postcopulatory courtship in the parasitoid wasp Spalangia endius (Hymenoptera: Pteromalidae)

The proximal mechanisms leading to monandry have been little studied in most insect orders, including Hymenoptera. In the parasitoid wasp Spalangia endius, mated females are less attractive (less often mounted) than virgins and are unreceptive (unlikely to allow copulation). Which aspects of mating are responsible was tested by observing male responses toward females whose mating had been interrupted at various stages. All females were allowed to receive precopulatory courtship and to open their genital aperture to copulate. Then some were interrupted before copulation, some after copulation but before postcopulatory courtship, and some were allowed to complete postcopulatory courtship. Females that had copulated were not less attractive than females that had not. In contrast, females that had received postcopulatory courtship were clearly both less attractive and less receptive. Thus, postcopulatory courtship functions as extended mate guarding, by making the female less attractive and less receptive to subsequent males even after the original male is no longer present. The effect of postcopulatory courtship on female attractiveness was persistent but imperfect: when males were presented sequentially to mated females, most but not all males retreated without mounting, and a female could repulse more than twenty males in succession.     

Males' visits to females' webs and female mating receptivity in the spider,Agelena limbata (Araneae: Agelenidae)

Field observation on the reproductive behaviour in the funnelweb spider,Agelena limbata, was conducted. Copulation occurred primarily during the day. Some females copulated with different mates more than once. Females did not copulate immediately after their final moult and exhibited unpredictable mating receptivity patterns. Most males remained in females' webs for less than 1 day and copulated within the day of the visit. Males did not adopt a mating tactic of staying with a juvenile female until she moulted and matured, searching instead for adult female potential mates.     

Mating Resets Male Cricket Aggression

An animal’s motivational state can significantly impact its behavior. We examined the effects of mating on the aggression of male Acheta domesticus crickets. Pairs of males were allowed to establish dominance and subordinance and were then physically separated. Subordinate males were then allowed to either copulate with a female or to have chemo-tactile contact with, but to not copulate with, a female. Less than 15 min after separation, all male pairs engaged in a second agonistic encounter. Subordinate males that copulated with females were significantly more aggressive toward their dominant partners than un-mated subordinate males. Many mated subordinates became dominant. Allowing a subordinate male to contact, but not copulate with, a female had a similar effect, suggesting that chemo-tactile cues from the female are sufficient to elicit this change in aggression.     

Male Competition over Access to Females in a Spider with Last-Male Sperm Precedence

Agonistic behaviour between male cellar spiders (Pholcus phalangioides) was investigated to test whether (1) size difference determines which male achieves access to the female, (2) males are able to monopolize access to the female until egg laying and whether (3) female resource value increases before egg laying because of last‐male sperm precedence. We further investigated whether (4) there is variation in time and energy spent on courtship and copulation depending on the degree of sperm competition, i.e. with or without rival present. In three experimental settings we introduced two males of either different or similar sizes, or a single male to a female. The mating units were constantly video‐observed until the females produced their first egg sac. Experience, ownership and female resource value in terms of body size was controlled. Our results show that larger males achieve almost exclusive access to females. Size symmetrical settings resulted in increased fighting activity and duration but dominance did not influence mating success. If copulations were disturbed by the rival male, copulations were terminated earlier in symmetrical settings compared with asymmetrical settings. In 94.8% of trials only one copulation took place, suggesting that the copulating male successfully monopolized access to the female. Males confronted with a rival copulated longer but courted significantly shorter than lone males. Although the last male to copulate sires 88% of the offspring in P. phalangioides, neither fighting nor courtship activity increased before the female laid a batch of eggs. This suggests that males have no indication of the timing of oviposition.     

EVIDENCE FOR WIDESPREAD COURTSHIP DURING COPULATION IN 131 SPECIES OF INSECTS AND SPIDERS,AND IMPLICATIONS FOR CRYPTIC FEMALE CHOICE

Male courtship behavior is generally thought to function prior to copulation, as an inducement to the female to allow the male to copulate with her; this study indicates however, that male courtship during and following copulation (“copulatory courtship”) is common in insects and spiders (81% of 131 species in 102 genera and 49 families, mostly Coleoptera, Hemiptera, Diptera, and Araneioidea). Copulatory courtship is apparently evolutionarily labile, as expected if it is under sexual selection; intrageneric variation occurred in all 17 genera in which more than one species was observed. In 81% of 94 species with copulatory courtship, the male abandoned the female soon after copulation ended; thus, copulatory courtship appears not to function generally to induce acceptance of further copulatory attempts. The most likely explanation for copulatory courtship is that it represents attempts by males to influence cryptic female choice. This suggests that an aspect of sexual selection by female choice not considered by Darwin may be more important than previously appreciated and that the common practice in evolutionary studies of measuring male reproductive success by counting numbers of copulations may sometimes be misleading because of cryptic female choice during and after copulation.     

Nuptial gift in the spider Pisaura mirabilis maintained by sexual selection

The nuptial prey gift in the spider Pisaura mirabilis has been suggested to function as a male protection against sexual cannibalismduring courtship and mating. This hypothesis together withtwo alternatives—male mating effort and paternal investment hypotheses—were tested in a laboratory experiment withsexually inexperienced males and females. One group of malesoffered no gift to the female while three groups of males offeredsmall, medium, or large sized gifts, respectively. No malewas cannibalized among 82 trials. Aggression was observed onlyin encounters where a gift was presented. Males without a gift courted females, and 40% of these males managed to copulate,compared to 90% of males offering a gift. The copulation durationwas positively correlated with gift size. In general, the femaleterminated the copulation and ran away with the gift. The proportionof eggs fertilized increased with copulation time. Presenceor size of the nuptial gift did not affect female fecundityor spiderling size significantly. The results refute the hypothesesof sexual cannibalism and paternal investment. The nuptialgift represents a male mating effort; it entices the femaleto copulate, facilitates coupling during copulation, and byprolonging copulation it may increase the amount of sperm transferred.I conclude that the nuptial prey gift in Pisaura mirabilisis maintained by sexual selection.     

Ultrasonic courtship songs of male Asian corn borer moths assist copulation attempts by making the females motionless

Males of the Asian corn borer moth Ostrinia furnacalis (Guenée) produce an ultrasonic courtship song of extremely low‐intensity during copulation attempts. The song has been shown to significantly increase the mating success of the male; however, the mode of action of the sound in courtship remains to be resolved. Behavioural experiments using pairs with deafened females or muted males show that, without the aid of the sound, 63% of males eventually succeed in mating after several copulation attempts, whereas the remainder (37%) make repeated attempts in vain until interrupted by the escape of the female. Because few (2%) males fail to copulate when females hear the courtship song, it is evident that the song has an effect on females, promoting the success of copulation attempts. In support of this view, males produce louder songs if the first copulation attempt fails, suggesting that the males increase their sound levels to achieve successful copulation. It is suggested that the ultrasonic songs of the male render the females motionless, which is the same response as that to ultrasonic bat calls. Because even slight movements by the female can interfere with the attempt of the male to copulate, it is likely that, by making her motionless, the success rate of a single copulation attempt is increased greatly.