Reproduction in three species of rainbowfish (Melanotaeniidae) from rainforest streams in northern Queensland, Australia

Abstract – The reproductive biology of three species of rainbowfish (Melanotaeniidae) in northeastern Australian rainforest streams was investigated. Two species, Melanotaenia eachamensis and Cairnsichthys rhombosomoides are endemic to the area, whereas the third, M. splendida splendida, is more widespread. The species were all highly fecund, producing many hundreds of eggs between 1.10 and 1.24 mm in diameter. Melanotaenia eachamensis was the most fecund, produced the largest eggs of the three species, and consequently exhibited the greatest maternal investment (as measured by gonadosomatic index). The majority of reproductive effort occurred during the dry season, although reproductively active fish were present year-round for each of the species, but particularly so for M. s. splendida and C. rhombosomoides. No evidence for a role by temperature or photoperiod as environmental cues for reproduction was found, and it was suggested that gonad development was strongly tied to somatic growth. The concentration of reproduction to the dry season ensures that larvae are produced during a period of relatively stable and benign physical conditions. Comparison of temporal changes in gonadosomatic index values suggest that the spawning season of M. eachamensis , which occurs in high-elevation streams, is more restricted and commences about 1 month earlier than either other species. A similar phenology was observed for the M. s. splendida population found at high elevation and highlights the potential for spatial differences in stream productivity to influence life history. ^Note     

褐藻羊栖菜繁殖生物学特征和生活史流程的补充研究

以温州市洞头区人工养殖羊栖菜和野生羊栖菜为研究样本,详细描述了羊栖菜成熟孢子体有性生殖,假根与侧生枝无性生殖的繁殖生物学特征和生活史流程。详细记录了羊栖菜卵、精子和受精卵的减数分裂和有丝分裂过程,假根、茎(主茎和侧生茎)、叶(气囊)和生殖托(雌托和雄托)等4类器官生长、发育和分化过程,胚、幼孢子体和成熟孢子体形态结构特征。在此基础上对现有羊栖菜繁殖生物学特征及生活史流程进行了补充和修正,增加了羊栖菜侧生枝无性生殖和羊栖菜幼孢子体期有性生殖的相关内容,并重新绘制了羊栖菜生活史流程图。该研究结果将为开展羊栖菜养殖生态学研究,深层次解析羊栖菜生殖节律、种群繁衍与环境关系奠定基础。     

黄土高原健康生命研究

黄土高原,孕育了中华民族和延续五千年的灿烂文化。但随着历史车轮的向前辗转,黄土高原上出现了生态危机,并且越来越严重。本文运用生态伦理学的有关理论,根据黄土高原的基本特征和所面临的危机,提出了黄土高原健康生命的概念,以及建立黄土高原健康生命的目的,并尝试建立起黄土高原健康生命的指标体系。最后在此基础上探讨了维持黄土高原健康生命的途径。旨在通过此类研究唤起人们对黄土高原的重新认识,唤醒人类对黄土高原的尊重,我们要视黄土高原为一生命体,与之和谐相处,做到可持续发展。     

《图书情报工作》办刊理念探讨

基于相关统计资料,探讨了《图书情报工作》在功能定位、栏目设置、作者队伍、编辑质量、学术影响以及社会效益和经济效益等方面的办刊理念,并就该刊今后的发展方向提出了建议。     

Characteristics and dynamics analysis of Populus euphratica populations in the middle reaches of Tarim River

Populus euphratica Oliv. is widely distributed along the Tarim River. Maintaining stability of P. euphratica population is important to local development. This study explored the static life table, survivorship curves and four function curves (survival rate, cumulative mortality rate, mortality density, and hazard rate), and development index of P. euphratica population in the middle reaches of Tarim River. The results indicated that the age structure of P. euphratica population belonged to positive pyramidal type, which meant young age-class individuals occupied most populations. The number ofⅠ-Ⅱage classes accounted for 66.2% of whole population, and this indicated that there were abundant subsequent seedlings resources to support the growth of P. euphratica population in the middle reaches of Tarim River. The survivorship curve of P. euphratica belonged to the Deevey Ⅲ (concave-type) and the development index was 47.72%. Four function curves revealed that the individuals of P. euphratica sharply decreased at the initial stage and then leveled off at the late stage of survival curve. Time sequence prediction models predicted that the number of midlife individuals would increase in future 10, 20, 30 years, and P. euphratica population grew steadily as a result of rich saplings.     

不同温度下的豌豆蚜实验种群生命表研究

在6种温度(12、15、18、21、24℃和27℃)和相对湿度为80%的条件下,研究了温度对豌豆蚜发育和增殖的影响。组建了生命表,并统计出种群内禀增长率、净增殖率、世代平均周期、种群加倍时间和周限增长率等种群动态参数。结果表明,在试验温度范围内,豌豆蚜的发育历期随温度升高而缩短。种群的内禀增长率在24℃条件下最大(rm=0.281 0),相应的种群净增殖率(R0)、周限增长率(λ)、平均世代周期(T)和种群加倍时间(t)分别为17.030 9、1.324 5、10.089 3 d和2.466 7 d。     

不同温度下东方粘虫年龄-阶段两性实验种群生命表的构建

为明确不同温度对东方粘虫Mythimna separata(Walker)种群动态的影响,建立东方粘虫种群动态模型,利用年龄-阶段两性种群生命表得到了室内不同温度下东方粘虫种群的发育历期、存活率、繁殖力和种群生命表参数,并基于种群生命表参数预测了2个月内东方粘虫的种群动态。结果表明,东方粘虫各虫态的发育历期和产卵前期随温度的升高而显著缩短。24℃下,东方粘虫单雌平均产卵量为717.1粒,显著高于其它温度下;成虫寿命也显著高于其它温度下,且雄蛾寿命显著长于雌蛾,分别为15.3 d和13.0 d;卵孵化存活到成虫的概率、幼虫存活率和化蛹率均最高,分别为66.7%、68.9%和96.8%。内禀增长率随温度的升高而显著增加,平均世代周期则显著降低,18、21、24、27、30℃下分别为0.051、0.077、0.113、0.121、0.156 d-1和77.2、61.3、49.0、40.3、31.5 d;周限增长率也随温度的升高而增加,分别为1.05、1.08、1.12、1.13、1.17 d-1;净增殖率在24℃下为257.1,显著高于其它温度下,其它温度条件下无显著差异。表明东方粘虫在18~30℃范围内都能完成生长发育和生殖,24℃下种群存活率高、繁殖力大、世代周期较短,更适合种群增长。     

害草薇甘菊生防因子——安婀珍蝶的自然种群生命表研究

室外设立隔离网笼，在自然气候条件下，饲养、释放薇甘菊重要生防因子——安婀珍蝶，研究了安婀珍蝶野外释放后对广东地区环境的适应能力；利用庞雄飞作用因子组配的生命表方法，组建安婀珍蝶自然种群生命表，量化分析评价各因子对安婀珍蝶的影响。结果表明：释放安婀珍蝶两代的自然种群趋势指数分别为0．0872和0．0939，都非常低，安婀珍蝶野外增殖能力较差。第一代和第二代中“捕食与其他”的控制作用指数分别为190．0191和84．8973，均高于其他因子的控制作用，“捕食与其他”为影响安婀珍蝶生长发育的重要因子。综合上述结果认为，需通过大量饲养人工释放、补充幼虫数量的方法，逐步提高安婀珍蝶在野外建立自然种群的能力。     

应用实验种群生命表评价巴氏新小绥螨对西花蓟马的控制能力

以西花蓟马Frankliniella occidentalis(Pergande)(Thysanoptera,Thripidae)一龄若虫为猎物组建巴氏新小绥螨Neoseiulus barkeri(Hughes)(Acari:Phytoseiidae)实验种群生命表,获得净生殖力Ro=27.37,世代平均历期T=22.17天,内禀增长率rm=0.15,周限增长率λ=1.16,种群倍增所需时间t=4.64天等参数。将获得参数值与西花蓟马的相关参数值进行比较,巴氏新小绥螨瞬间增长率大于西花蓟马的瞬间增长率(0.14),雌成螨日取食7～12头西花蓟马一龄若虫,表明巴氏新小绥螨可以作为控制西花蓟马种群数量的有效天敌。