丽纹攀蜥精巢染色体和减数分裂研究

本文用精巢细胞制片法,在国内首次报道了丽纹攀蜥(Japalura splendida)的精巢染色体组型和减数分裂过程,其精巢染色体n=17,含6个大型染色体和儿个微小染色体。除微小染色体呈点状外,大型染色体均为中间着丝粒染色体。同时我们观察了丽纹攀蜥减数分裂各个时期,并对各时期的特征进行了描述。     

中国八种麻蜥(蜥蜴科,麻蜥属)形态学研究

对8种麻蜥外部形态进行主成分分析,可分为4个种组:1)丽斑麻蜥Eremias argus与山地麻蜥Eremiasbrenchleyi;2)快步麻蜥Eremias velox与虫纹麻蜥Eremias vermiculata;3)密点麻蜥Eremias multiocellata、荒漠麻蜥Eremias przewalskii与敏麻蜥Eremias arguta;4)网纹麻蜥Eremias grammica.研究表明丽斑麻蜥前额鳞数不稳定;密点麻蜥莎车亚种Eremias multiocelfata yarkandensis可能为独立物种;荒漠麻蜥物种有效性值得怀疑.     

红腹锦鸡和丽纹龙蜥视网膜的组织学观察

为了进一步探讨动物视网膜结构与机能的关系,利用光镜和扫描电镜比较观察了红腹锦鸡(Chrysolophus pictus)、丽纹龙蜥(Jspalura splendida)视网膜的结构。结果表明,红腹锦鸡、丽纹龙蜥的视网膜均由四层细胞构成,在光镜下均可分为十层结构。红腹锦鸡视网膜平均厚225·2μm,视细胞与节细胞数比约为2:1;丽纹龙蜥视网膜平均厚156.2μm,视细胞与节细胞数比为1:1。红腹锦鸡、丽纹龙蜥视网膜视细胞的平均密度分别为(124828±24404)个/mm2和(33165±7034)个/mm2。显示了红腹锦鸡和丽纹龙蜥均具有昼行性动物视网膜的结构特征。     

丽纹攀蜥头体大小的两性异形和繁殖期的生长

测定了丽纹攀蜥的体长、头长、头宽、头高、尾长和体重等形态指标,以及通过44天的生长后体长、头长、头宽和头高的增长。表明成年两性个体体长无显著的两性异形,局部形态特征皆与体长呈正相关。协方差分析表明,雄性的头长、头宽、头高和尾长显著大于雌性个体,繁殖期雌性个体的体重显著大于雄性个体。丽纹攀蜥繁殖期雄性体长的增长显著大于雌性体长的增长,雌雄两性头长、头宽和头高的增长无显著的差异。     

两种麻蜥卵和孵出幼体的特征

研究了山地麻蜥和丽斑麻蜥实验条件下的卵及孵出幼体的特征.山地麻蜥产卵雌体的体长大于丽斑麻蜥,窝卵重小于丽斑麻蜥,但平均卵重和相对窝卵重与丽斑麻蜥相似.两种蜥蜴均通过增加卵长径和卵短径来增加卵重,但卵的外形不同,山地麻蜥卵较长.两种蜥蜴卵孵化过程中均吸水增重.相似孵化条件(波动温度、-12 kPa)下,山地麻蜥的孵化期明显比丽斑麻蜥长.山地麻蜥幼体的尾、头部大于丽斑麻蜥,但体重和SVL相似.     

巴塘攀蜥的再描述（图版封3）

1824年德国人Theodore von Vogt报道四川巴塘有云南攀蜥和草绿攀蜥,后来我国学者否定了巴塘有云南攀蜥,认为有草绿攀蜥,但这种草绿攀蜥极有可能是巴塘攀蜥。2001年李操等根据浸制标本报道了新种巴塘攀蜥（Japalura batangensis）由于其没有看到生活标本,所以在形态特征的描述上就有不足之处。2004年我们到四川甘孜州考察两栖爬行动物,8月在巴塘县竹巴笼乡采到6只巴塘攀蜥,经几个月的室内养殖观察和特征鉴定,特此再作形态和行为的补充描述。     

四川几种攀蜥的行为和繁殖观察

198 7～ 2 0 0 3年通过野外采集或室内饲养 ,对四川西部的几种攀蜥的栖息环境、活动规律、变色现象、摄食和繁殖等进行了观察。发现汶川攀蜥卵在孵化过程中有逐渐长大、增重的现象。     

巴塘攀蜥的再描述

1824年德国人Theodore von Vogt报道四川巴塘有云南攀蜥和草绿攀蜥,后来我国学者否定了巴塘有云南攀蜥,认为有草绿攀蜥,但这种草绿攀蜥极有可能是巴塘攀蜥。2001年李操等根据浸制标本报道了新种巴塘攀蜥(Japalura batangensis)由于其没有看到生活标本,所以在形态特征的描述上就有不足之处。2004年我们到四川甘孜州考察两栖爬行动物,8月在巴塘县竹巴笼乡采到6只巴塘攀蜥,经几个月的室内养殖观察和特征鉴定,特此再作形态和行为的补充描述。巴塘县竹巴笼乡归洼村,地处横断山脉北段,金沙江东岸的峡谷地带,东高西低,山峦起伏,山势陡峭,土层瘠薄…     

四川几种攀蜥的行为和繁殖观察(图版Ⅸ,下)

1987～2003年通过野外采集或室内饲养，对四川西部的几种攀蜥的栖息环境、活动规律、变色现象、摄食和繁殖等进行了观察。发现汶川攀蜥卵在孵化过程中有逐渐长大、增重的现象。     

丽纹攀蜥粗线期染色体核型及微小染色体的分析

本文以精巢、四肢骨和脊椎骨为材料,利用直接制片法制备了丽纹攀蜥（Japalura splendida）染色体标本,首次对其精巢减数分裂粗线期染色体,特别是微小染色体的长度进行了测量,描述了染色体特征,并进行了核型分析.同时与二倍体细胞染色体的核型进行了比较,发现11对微小染色体类型中包括8对中着丝粒染色体、2对端着丝粒染色体和1对点状染色体.     

First observation on the mating behaviour of the marbled ray, <Emphasis Type="Italic">Taeniurops meyeni,</Emphasis> in the tropical Eastern Pacific

Elasmobranch reproductive behaviour remains understudied, particularly for batoids (rays). Most of the information available originates from opportunistic observations of mating scars in the wild and/or from individuals held in captivity. Here we describe the first complete mating sequence of the marbled ray (Taeniurops meyeni) in the wild. The event was filmed at Isla del Coco National Park in Costa Rica, in the Tropical Eastern Pacific. The complete sequence lasted approximately 3 hrs and is defined by the following behaviours: (1) close following or chasing: a group of males swim in a close formation chasing an individual female; (2) pre-copulatory biting: oral grasping of the female’s posterior pectoral fin by the males, with anterior bending of one clasper and rotation of the pelvic region towards the female’s cloaca; (3) copulation/ insertion of the male’s clasper followed by ‘ventral to ventral’ position and energetic thrusting of the male’s pelvic region; (4) post-copulatory behaviour: the male removes its clasper from the female’s cloaca while releasing her posterior pectoral fin and (5) separation: the male sets the female free and separates himself from the group. The mating behaviour described here shares some similarities with the few other studies of batoids in the wild and highlights the need to further understand their mating system to guide conservation plans for this vulnerable species.     

Aquatic eggs are fertilised by multiple males not engaged in amplexus in a stream-breeding frog

In anuran amphibians, multiple males amplexing a single female to fertilise her eggs has been found for less than 25 species, whereas matings without amplexus are known for less than five species. Here we provide a new example of simultaneous polyandry with multiple males not engaged in amplexus, in Feirana taihangnicus, a stream-dwelling, explosive breeder endemic to central China. Laboratory experiments showed that when one female was kept with one male in a vessel with elevated, flat stones, the female stood on her head with her swollen cloaca against the undersurface of the stone substrate to lay eggs (clutch size ranged from 371 to 533, n = 7 females). Then, 10–102 min after oviposition began, the male stood on his head and released sperm over the eggs distributed as a single layer on the stone surfaces. It took about 3 h for the female to finish oviposition and for the male to finish fertilisation. On average, 96% of eggs were fertilised. In natural oviposition habitats, stream sections with slow flowing, we observed that 1 up to 15 males (8.7 ± 6.6, n = 6 cases), none in amplexus, participated in fertilising the eggs deposited by a single female. Evolutionary implications of this unusual reproductive strategy remain to be explored.     

Ecology and reproductive patterns of the agamid lizard Japalura swinhonis on an east Asian island, with comments on the small clutch sizes of island lizards

I describe the habitat use, diet, and the male and female reproductive cycles of Japalura swinhonis, an oviparous agamid lizard inhabiting Orchid Island, a tropical island off the southeastern coast of Taiwan. Ninety percent of lizards (n=126) were observed on tree trunks or at the forest edge. The diet of J. swinhonis on Orchid Island consisted mostly of hymenopterans (53.33%) and orthopterans (16.67%). The mean snout-vent length (SVL) of adult males was 74.58 (n=89) and that of females was 69.31 (n=37) mm. Females exhibited a long vitellogenic period from November to February, with parturition occurring from March to October. The onset of vitellogenesis did not correlate with the mass of the female fat bodies. Females produced two to five eggs per clutch, and clutch size was not correlated with SVL. Two clutches were recorded during a single year in some individuals. Clutch size in J. swinhonis was compared with that in other Japalura species. Clutch sizes of Japalura species are larger in mainland China than on insular Taiwan. Clutch size is also mainly affected by environmental constraints, and smaller clutch sizes are probably affected by predators on Orchid Island.     

Precopulatory mate guarding and mating behaviour in the rotifer Epiphanes senta (Monogononta: Rotifera)

Epiphanes senta is a littoral rotifer species that occurs in temporary waters and displays a mating behaviour which has not, to my knowledge, so far been described for monogonont rotifers. Monogonont rotifers show distinctive periods within their life cycle during which mictic females appear. Mictic females produce haploid eggs that develop into males or into diapausing eggs if fertilized. The females of E. senta are mostly stationary on the substrate while males are more active swimmers. If they encounter eggs with female embryos of their own species, they attend them and mate with the hatching female. Experiments showed that males are able to discriminate between male, female and diapausing eggs. They exhibit a strong preference for female eggs that are only a few hours away from hatching compared with eggs in early developmental stages. Further experiments did not show any significant differences in male attendance of mictic and amictic eggs. It is hypothesized that males judge the age of a female egg by sensing a chemical that is produced by the growing embryo and diffuses through the egg shell. The male mating behaviour is similar to precopulatory mate guarding known from arthropods but it lacks the monopolization of the female by the male.     

Learning enhances female control over reproductive investment in the Japanese quail

The adaptive significance of learning is supported by studies showing its positive effects on mating behaviour, but they rarely go beyond fertilization success. Here we studied how learning contributes to qualitative reproductive investment, by testing the hypothesis that mating in the context that predicts male appearance has positive effects on female reproductive investment compared with unsignalled mating. Using Japanese quail (Coturnix japonica), we found that effects of mating in the context predicting mating opportunity depend on female body condition and receptivity, while the outcome of unexpected mating depends on male behaviour. In particular, among females mated with the familiar male in the context predicting that he will appear, female condition positively affected the number of fertilized eggs and egg mass and more receptive females tended to produce more sons. Additionally, conditioned females laid heavier eggs for daughters than for sons. In contrast, in females that were mated unexpectedly and with a novel male, the number of fertilized eggs was highly dependent on male behaviour and was negatively related to maternal body condition. Egg mass was not related to body condition, and there were no indications of sex allocation. This is, to our knowledge, the first study demonstrating how female body condition and behaviour interact with the context of mating in shaping maternal reproductive investment.     

绿豆象气味结合蛋白基因的克隆及表达分析

【目的】对绿豆象Callosobruchus chinensis气味结合蛋白(odorant binding proteins, OBPs)基因进行克隆、鉴定和组织表达分析,为研究OBPs在绿豆象嗅觉感受过程中的功能奠定基础。【方法】基于绿豆象触角转录组数据,通过RT-PCR克隆绿豆象6个OBP基因并进行生物信息学分析;通过qRT-PCR分析OBP基因在绿豆象雌雄成虫头(不含触角)、触角、腹、足和翅各组织中的表达情况。【结果】获得了6个绿豆象OBP基因的开放阅读框,命名为CchiOBP1-CchiOBP6(GenBank登录号: MN832700-MN832703, MN901841-MN901842);CchiOBP5为一段C端不完整的Minus-C OBP,其余均属于完整的Classical OBPs,预测6个CchiOBPs均含有信号肽。系统发育分析表明CchiOBP1, CchiOBP2和CchiOBP5与叶甲科(Chrysomelidae)昆虫OBPs的亲缘关系较近,CchiOBP3, CchiOBP4和CchiOBP6与天牛科(Cerambycidae)昆虫OBPs的亲缘关系较近。qRT-PCR结果表明,6个CchiOBPs基因在绿豆象成虫的触角、头(不含触角)、腹、翅和足部均有不同的表达量,CchiOBP1-4和CchiOBP6在雌雄成虫触角中均呈现高表达,且极显著高于在其他组织中的。CchiOBP5在雌成虫触角和头部(不含触角)中呈现高表达,但在雄成虫中表现为在足部的表达量显著高于在其他组织中的,在触角中的表达量最低。【结论】确定了绿豆象6个CchiOBPs基因的核苷酸和氨基酸序列组成,其中有5个CchiOBPs基因在绿豆象雌雄成虫触角中高表达,推测其在绿豆象嗅觉识别寄主植物过程中发挥重要作用。     

Scatter-spawning of the catfish,Silurus asotus

Reproductive behaviour of the catfish,Silurus asotus was studied in temporary waters around paddy fields. Spawning occurred nocturnally during the first week from the initiation of irrigation. In reproductive activities, a male first energetically pursued a female with its head near to the female’s belly (chasing) and then began to cling to the female’s body from the side, bending its tail or head (clinging). Finally the male enfolded the female’s body, with its anus near to the female’s (enfolding). In some cases, 2–4 males pursued a single female and two males enfolded a female at the same time. Although no aggressive behaviour was evident between males, it was always the largest male that could most frequently approach and enfold the female. The mating pair moved a long distance in a ditch, paddy field and/or creek, performing reproductive activities. It is thought that the spawning site and period of spawning of the fish enable the larvae to avoid the danger of predation and to efficiently feed, firstly on plankton and later on larvae of other fishes which become abundant during the irrigation period. Although some eggs and larvae may die due to the drying out or high water temperatures of such unstable temporary waters, scattering eggs may reduce the incidence of the annihilation of the young.     

多疣狭口蛙昆明种群雌雄配对行为及形态适应选择

测量和比较采自昆明东北郊的24对抱对多疣狭口蛙(Kaloulaverrucosa)标本,同时野外观察其繁殖行为。配对雌雄蛙的体长、体重和头宽3个形态特征的Pearson相关系数大于0·5;择体长和体重作回归分析,结果表明,雌雄蛙体长选择和雌雄蛙体重配对都呈良好的线性关系。雌蛙选择雄蛙体长为自身体长的(81·8±5·7)%、体重为自身体重的(53·1±10·7)%的个体为最适配偶。雌蛙选择体长较长而体重较轻的雄蛙作为配偶,这样有利于形成较好的空间(雄性胸腹部皮肤腺长度,雌雄抱对时泄殖孔位置等)配对关系。多疣狭口蛙属于雌性选择模式,即雄蛙鸣叫,雌蛙受吸引,主动接近雄蛙,如果雄蛙条件适合则形成配对。     

Type of intruder and reproductive phase influence male territorial defence in wild-caught Siamese fighting fish

This study investigated how parental care increases with offspring age by examining the level of male aggressiveness toward potential intruders during egg guarding in a natural population of Siamese fighting fish (Betta splendens Regan). The degree of aggressiveness was measured at two reproductive phases in response to three types of intruders: male, female and females that have laid eggs. The nest-holding males became more aggressive after their eggs hatched than after the eggs were laid. Nest-holding males displayed gill cover erection, biting, tail beating and attacking at the highest rate towards male intruders, intermediate towards female intruders and the least aggressive towards females, which have laid eggs.