Sex Discrimination in Gerris remigis: Role of a Surface Wave Signal

Even when blinded with masks, adult male water striders (Gerris remigis) accurately ascertain the sex of other adult water striders in the laboratory. Freely moving females that were artificially made to play back computer-generated male surface wave and body-contact signals of about 90 waves per second were treated as males by the masked males and as females when no such playbacks were made. Thus, the males can use presence or absence of the male signal as the sole means for sex discrimination.     

Creation of a free European bison population in the Northwestern region of Russia

A free population of European bisons has been created in the Vologda oblast. The habitat area is 1300 ha. One male and two females were acquired in 1991. The population size in 2008 was 22 bisons—three males, six females, five head of young stock up to 2 years old, and eight head older than 2 years.     

普通大蓟马子代性比对同种成虫气味的响应

为了探究同种成虫的气味对普通大蓟马(Megalurothrips usitatus)交配期间性比调节的影响,设置对照（无气味）、已交配雌虫、未交配雌虫和已交配雄虫等4种气味源,分别处理单对刚羽化成虫24 h,然后用幼嫩豇豆(Vigna unguiculata)豆荚单头饲养被测雌虫,观测每日所产子代的性别和数量,计算子代性比。结果表明:已交配雌虫气味处理的子代雌虫数（22.80头）最少,跟其他处理差异显著。同对照的子代性比（0.31）相比,已交配雌虫和未交配雌虫的气味分别导致子代性比显著提高和降低,子代性比分别为0.48和0.22,而已交配雄虫气味对子代性比无显著影响。4个处理中,仅已交配雌虫气味处理的雌虫在产卵最后1天的日性比达到1.00,即雌虫体内的精子已消耗殆尽。成虫气味源对雌虫产卵天数没有明显影响。实验结果说明,普通大蓟马在交配期间能依靠嗅觉判别周边雌虫的交配状况,然后通过调控雌虫的获精数量,实现对子代性比的自调节。     

The Ecological Significance of Sexual Dimorphism in Size in the Lizard Anolis conspersus

Adult males of Anolis conspersus capture prey of significantly larger size and occupy perches of significantly greater diameter and height than do adult females; similarly, these three dimensions of the niche are significantly larger for adult females than for juveniles. Adult males on the average eat a smaller number of prey, and the range in size of prey is larger. The relationship between the average length of the prey and that of the predator is linear when the predator size is above 36 millimeters, but becomes asymptotic when it is below that value. Subadult males as long as adult females eat significantly larger food than do the latter, but only in the larger lizards is this correlated with a relatively larger head. Anolis conspersus selects prey from a wide range of taxa and shows no obvious intraspecific specialization not connected to differences in microhabitat and prey size. The efficiency of this system for solitary species is pointed out.     

年龄和性别对圈养马麝非交配季节行为持续时间的效应(英文)

    采用焦点取样和连续记录方法,对甘肃兴隆山麝场的圈养马麝(Moschus sifanicus)进行行为观察和记录.行为取样涉及30头雌性马麝(25头成体雌麝,5头亚成体雌麝)和24头雄性马麝(17头成体雄麝,7头亚成体雄麝).记录静卧、站立凝视、运动、摄食、反刍、蹭尾、粪尿标记、环境探究、尾阴探究、亲和、打斗及自我指向行为等12个行为类的发生持续时间,分析年龄和性别对圈齐马麝非交配季节行为持续时间的效应.结果表明,在非交配季节,由于雌麝的哺乳育幼及雌麝和幼麝间的社会行为,雌麝比雄麝展现较少的卧息(P<0.01)和较多的亲和行为(P<0.05);由于雌麝在非交配季节的育幼需求及伴随的警觉性增加,成体雌麝比亚成体雌麝的摄食时间极显著减少(P<0.01),警觉行为显著增多(P<0.05);相比亚成体雄麝,成体雄麝的蹭尾行为持续时间极显著地增多,打斗行为和尾阴嗅闻行为的持续时间也显著较多(P<0.05).行为比较结果表明,圈养马麝各年龄性别组的行为持续时间存在差异,成年雌麝在哺乳期摄食时间相对较少,其育幼投资策略可能是提高摄食效率和警觉行为表达强度.     

Aggression in adult mice: modification by neonatal injections of gonadal hormones

Incidence of spontaneous aggression in adult male mice given a single injection of estradiol benzoate (0.4 milligram) when they were 3 days old was less than that of controls injected with oil. Aggressiveness was increased among adult females injected with either estradiol or testosterone propionate (1 milligram) at the same age. The increased aggressiveness noted among females given androgen was further documented during subsequent mating tests, when these females often attacked, wounded, and, in one case, killed naive males.     

Plasma testosterone levels in the male rhesus: influences of sexual and social stimuli

Four adult male rhesus monkeys were provided access individually to a group of receptive females. Each male assumed dominance and engaged in frequent copulations. Plasma testosterone levels increased two- to threefold during this period. Next, each male was subjected to sudden and decisive defeat by a large all-male group, and plasma testosterone fell following this experience. Two males were later reintroduced to the females, and plasma testosterone rose rapidly to the previous elevated levels.     

亮腹釉小蜂不同发育阶段的形态及寄生行为

【目的】研究柑橘木虱Diaphorina citri优势寄生蜂亮腹釉小蜂Tamarixia radiata的个体发育形态学及寄生行为,为柑橘黄龙病的生物防控提供理论和技术指导。【方法】在温度为(26±1)℃、相对湿度为60%~80%的试验条件下,观察亮腹釉小蜂寄生行为及个体发育形态,并测量形态学指标。【结果】亮腹釉小蜂寄生柑橘木虱3~5龄若虫产卵;亮腹釉小蜂整个发育历程分为卵、幼虫、蛹、成虫4个阶段;室内条件下其世代发育历期约为13.40 d;雌虫个体明显大于雄虫;雄虫触角刚毛发达,几乎覆盖整个触角基节,而雌虫触角刚毛很短,触角基节清晰可见;雌虫腹部背面黄色区域明显大于雄虫。【结论】亮腹釉小蜂为柑橘木虱体外寄生蜂,雌、雄成虫形态有显著差异。     

Esterase 6 and reproduction in Drosophila melanogaster

A nonspecific carboxylesterase (esterase 6) of Drosophila melanogaster shows greater activity in adult males than in females and is highly concentrated in the anterior ejaculatory duct of the reproductive tract of the male. Esterase 6 is depleted in males by copulation and is transferred to females early during copulation as a component of the seminal fluid. That esterase 6 may be involved in a system controlling the timing of remating is suggested by differences in the activity of this enzyme in a strain of Drosophila selected for a decrease in time to remating and by differences in the timing of remating in females initially inseminated by males lacking or having active esterase 6.     

Androgens prevent normally occurring cell death in a sexually dimorphic spinal nucleus

The spinal nucleus of the bulbocavernosus (SNB) contains many more motoneurons in adult male rats than in females. Androgens establish this sex difference during a critical perinatal period, which coincides with normally occurring cell death in the SNB region. Sex differences in SNB motoneuron number arise primarily because motoneuron loss is greater in females than in males during the early postnatal period. Perinatal androgen treatment in females attenuates cell death in the SNB region, reducing motoneuron loss to levels typical of males. The results suggest that steroid hormones determine sex differences in neuron number by regulating normally occurring cell death and that the timing of this cell death may therefore define critical periods for steroid effects on neuron number.     

不同发育阶段中华绒螯蟹摄食行为及其对饵料选择性的研究

本研究通过养殖实验和摄食过程摄像技术,首先研究了中华绒螯蟹（以下简称河蟹）幼蟹、早期成蟹,亚成体和成体的摄食行为差异,评价了不同发育阶段和不同性别河蟹的摄食行为、摄食响应时间和摄食率差异,然后进一步比较了不同发育阶段河蟹对冰鲜鱼、配合饲料、玉米和螺蛳的摄食选择性。结果表明：（1）河蟹的摄食行为可分为探索、定位、试探和摄食这4个阶段,其中探索和摄食耗时较长。（2）就探索阶段的耗时和摄食响应时间而言,幼蟹和早期成蟹的雌体显著短于雄体,而亚成体和成体阶段雄体显著短于雌体。（3）就摄食而言,各发育阶段雌体的摄食耗时均高于雄体。（4）就摄食率而言,河蟹摄食率随着发育阶段的增加呈现显著下降趋势,而雌雄蟹间无显著差异。（5）就不同饵料的摄食选择性结果而言,不同发育阶段的河蟹对不同饵料的首次摄食频率从高到低顺序均是冰鲜鱼>配合饲料>玉米>螺蛳。（6）雌、雄成蟹对冰鲜鱼和配合饲料的摄食响应时间均无显著差异,但均显著低于对玉米和螺蛳。综上,不同发育阶段和不同性别河蟹的摄食行为存在显著差异,亚成体阶段是雌、雄河蟹摄食行为发生转变的重要发育阶段,成蟹优先摄食冰鲜鱼与配合饲料。     

白背飞虱交配和产卵行为研究

生殖行为是个体生物学的重要研究内容,本文对白背飞虱的交配、产卵等生殖行为进行了研究。结果表明:白背飞虱雌虫羽化昼夜节律高峰期在12∶00~14∶00,雄虫羽化高峰期比雌虫早,在10∶00~12∶00,交配昼夜节律高峰期在凌晨0∶00~2∶00和中午12∶00~14∶00,产卵昼夜节律高峰在12∶00~16∶00,雌雄成虫均可交配2次以上,雌虫多次交配后产卵量显著多于单次交配的雌虫,未经交配的雌虫也能产卵,但产卵量显著少于交配过的雌虫且所产卵不能孵化,表明白背飞虱不具有孤雌生殖现象。     

Behavioral patterns of captive alpine musk deer: sex-specific behavior comparisons

The aim of this study was to document the behavior of captive alpine musk deer and to determine if daily behavior patterns varied between females and males. From August 2002 to January 2003, focal sampling was used to observe 32 adult captive alpine musk deer (13 female and 19 male) at Xinglongshan Musk Deer Farm (XMDF), Xinglongshan National Nature Reserve, Gansu Province. Results indicated similar behavior patterns for males and females, with only two out of 12 recorded behaviors showing significant sex differences. In comparison to females, males rested for a longer duration and exhibited tail pasting more frequently. This study also provided the first recording of tail pasting by female musk deer.     

烟蚜茧蜂触角的超微结构与冷藏对触角的影响

【目的】明确烟蚜茧蜂（Aphidius gifuensis）触角和触角感觉器的外部形态及低温冷藏对其触角的影响,为烟蚜茧蜂的有效利用提供依据。【方法】采用扫描电镜观察正常羽化的烟蚜茧蜂雌、雄蜂触角的超微结构,比较雌、雄蜂触角感觉器的差异。将处于老熟幼虫期的烟蚜茧蜂在4℃低温下分别冷藏7、14、21和28 d,冷藏后用乙醇对样品进行脱水处理,并在扫描电镜下观察低温冷藏对烟蚜茧蜂触角外部形态及触角感觉器的影响。【结果】烟蚜茧蜂雌、雄成蜂触角外部形态相似,均属于丝状触角。雄蜂触角平均长度略长于雌蜂,雌蜂触角多为17节,雄蜂触角多为19节。成蜂触角上共有6种类型的感觉器：毛形感觉器、刺形感觉器、板形感觉器、Böhm氏鬃毛、腔锥形乳突状感觉器和锥形感觉器。毛形感觉器I主要分布在触角鞭节上,是触角上分布最广、数量最多的感觉器。板形感器主要分部在鞭节上,雄蜂从第1鞭节开始出现,雌蜂从第2鞭节开始出现。腔锥形乳突状感觉器II只存在于雄蜂触角上。雌、雄蜂感觉器的数量存在差异,雌蜂的刺形感觉器I数量多于雄蜂,雄蜂的刺形感觉器II和板形感觉器的数量则多于雌蜂。低温处理14、21、28 d后,板形感觉器、腔锥形乳突状感觉器均表现畸形,且触角最后两节分节不明显,有愈合成一节的趋势。冷藏28 d后,54%雄性触角不能正常分节,由正常情况下的19节而愈合为18节;69%的雌性触角不能正常分节,由正常情况下的17节而愈合为16节。【结论】烟蚜茧蜂触角属于丝状触角,共有6种类型感觉器。雄蜂触角长于雌蜂,感觉器的分布特点相似。低温冷藏对烟蚜茧蜂某些触角感觉器形态及触角末两节分节有显著影响。为减少冷藏对烟蚜茧蜂的伤害,应尽量避免在蛹期以前的虫态低温保存蜂种,且应缩短冷藏时间。     

Co-γ辐射对烟青虫飞翔和繁殖生物学的影响

 为了解杂交稻不育系抽穗不畅问题，以隐性长穗颈温敏核不育水稻长选3S为材料，采用田间调查和人工温度处理方法研究了温度对隐性长穗颈基因（eui）表达的影响。结果表明，长选3S穗颈伸出剑叶叶鞘的长度与始花前9～20 d自然条件下的日均温度呈负相关，其中以始花前12～17 d(花粉母细胞形成至减数分裂期)日均温度负相关性最显著。在eui基因表达对温度最敏感的时期进行4种人工温度处理，22℃、24℃、26℃和28℃。28℃条件下eui基因表达受阻；22～26℃条件下eui基因表达，且穗颈伸出剑叶叶鞘的长度随温度降低而增长。     

所罗门群岛海域长鳍金枪鱼繁殖生物学初步研究

根据2012年9-12月所罗门群岛海域采集的307尾长鳍金枪鱼样本,分析其性别比、性腺成熟度和性腺指数等繁殖生物学参数。结果表明：繁殖群体总性别比和性成熟个体性别比均不符合1：1（P〈0．05）,雄性个体比例大于雌性,性别比在产卵期间出现一定波动,但普遍小于1：1。性别比与个体大小密切相关,雄性比例随叉长增长而降低。性成熟度分析表明,产卵期间性成熟个体比例达到70％以上,其中存在大量的产卵后群体,未成熟比例较低。雌性不同性成熟度大小差异明显（P〈0．05）,但雄性并不明显（P〉0．05）。相同性成熟度雄性个体平均叉长均大于雌性,但并没有体现出一致的变化。雌、雄个体初次性成熟叉长分别为84．88cm和85．61cm。性腺指数（Gsi）在各性成熟度和叉长组间存在显著差异（P〈0．05）,雌性GSI大于1．2几乎全部为成熟个体,尤其GSI大于2普遍为即将产卵（V期）和产卵后（Ⅵ期）群体;雄性个体GSI普遍小于2,各叉长组雌性GSI普遍高于雄性,这表明雌性性腺发育较快。而调查期间9月GSI均值明显高于其他3月（P〈0．05）,综合分析认为该海域长鳍金枪鱼9—10月达到产卵高峰期。     

花曲柳窄吉丁潜在飞行能力初步研究

为了评估花曲柳窄吉丁的飞行潜能,利用昆虫飞行磨系统测定雌雄花曲柳窄吉丁成虫在不同光照时间、交配状态、取食状态和日龄条件下的飞行能力。结果表明:雌虫24 h内最远飞行距离5 500 m,雄虫最远飞行距离1 397 m,雌雄成虫 间飞行距离差异显著;雌虫在24 h光照时间下飞行距离比L/D(昼/夜)=16 h/8 h光照周期下更远;交配雌虫与未交配雌虫在飞行距离上有显著差异,交配后雌虫飞行距离更远,而交配对雄虫飞行能力无显著影响;经取食并休息的雌虫飞行距离显著大于不取食不休息的雌虫;不同日龄未取食的花曲柳窄吉丁雌虫飞行能力存在一定差异,1日龄飞行能力最弱,13日龄最强,从1~2日龄开始飞行距离增加,2~4日龄飞行距离随日龄增加而减少,而在4日龄后飞行距离又随着日龄的增加而增加。说明花曲柳窄吉丁具有较长距离飞行的潜能,这可为该虫的传播扩散和风险评估提供一定依据。      

Prenatal alcohol exposure alters adult expression of sexually dimorphic behavior in the rat

Saccharin preference and performance in a Lashley III maze were found to be altered in adult male and female rats that had been exposed to alcohol during gestation. Specifically, the sexual dimorphism normally observed in both behaviors was absent in fetal alcohol-exposed animals. The lack of sexual dimorphism appeared to result from a masculinization of the exposed females and a feminization of the exposed males.     

Comparative Study of Malathion Toxicity and General Esterases in Larvae and Adults from a Field Population of Oxya chinensis (Thunberg)(Orthoptera:Acridoidea)

The susceptibility of Oxya chinensis to malathion was compared in larvae and adults from a field population, collected from Jinyuan outskirt, Shanxi Province. The results showed that Oxya chinensis was more susceptible to malathion in the adult stage than in the larval stage. The LD50 values for malathion susceptibility of Oxya chinensis were 4.94 and 2.44 mg g-1 body weight in the larvae and adults respectively. The results indicated that the larvae were 2.02-fold less susceptible to malathion than the adults. The general esterases and the kinetics were characterized and compared between the two life stages and between females and males. Larval preparations of Oxya chinensis were more active than adult preparations in females and males. The larvae showed 1.18-, 1.49-, and 1.17-fold higher specific activities than the adults in females with α -NA, α -NB and β -NA respectively. In males, the ratios were 1.34-, 1.70-, and 1.06-fold. Female preparations were more active than those of males in the adults. The reverse results were observed in the larvae where male preparations were more active than female preparations. Kinetic studies showed that Km values of general esterases hydrolyzing α -NA, α -NB, and β -NA in the adult stage were 1.36-, 1.32- and 1.39-fold respectively, higher than those in the larval stage in females. In males, the ratios were 1.24-, 2.14-, and 1.20-fold. The esterase from male insects had a higher affinity (lower Km value) to the substrate than those from females. The results also showed that the Vmax values of general esterase hydrolyzing α -NA, α -NB, and β -NA in the two stages were similar. From the results of bioassays and biochemical analyses, it has been inferred that a higher level of resistance to malathion in larvae than in adults would appear to result from differences in the expression of resistance mechanisms in these two life stages. Enhanced esterase activities appeared to play a major role in resistance to malathion in both larvae and adults. From the analysis of inhibition in vitro, the esterases in the two life stages were B-type,and carboxylesterases were predominant enzymes in the composition of the esterases in the two stages.     

Female mate choice in a neotropical frog

Female Physalaemus pustulosus choose their mates and are more likely to choose larger males. There is a significant negative correlation between the size of the male and the fundamental frequency of one of the components of its advertisement call. Playback experiments demonstrate that females are capable of choosing larger males by distinguishing among differences in spectral components of the advertisement call.