金沙江一期工程对保护区圆口铜鱼早期资源补充的影响

2008、2010－2013年在金沙江下游水富／宜宾断面进行了鱼类早期资源调查,研究金沙江一期工程对长江上游珍稀特有鱼类国家级自然保护区圆口铜鱼早期资源补充的影响。共采获圆口铜鱼卵苗6190粒（尾）,其中鱼卵74粒、鱼苗6116尾;2013年向家坝水电站蓄水后在水富／宜宾断面未采集到圆口铜鱼卵、苗。各年圆口铜鱼卵苗江汛期和最大日径流量分别为：2008年6月12日－7月2日、3．79×107粒（尾）,2010年6月22日－7月10日、3．47×107粒（尾）;2011年6月23日－7月4日、9．58×107粒（尾）;2012年6月24日－7月13日、1．22×107粒（尾）。圆口铜鱼卵苗江汛与金沙江下游的水文流量持续增长相关,卵苗日径流量高峰值与洪峰过程较一致,最大日径流量基本先于最大水文流量前出现。圆口铜鱼繁殖盛期在6月中旬－7月上旬较短时间内（2～3周）。2008年向家坝水电站截流前长江上游珍稀特有鱼类国家级自然保护区的圆口铜鱼早期资源补充量为2．12亿粒（尾）;2010－2012年导流施工期间早期资源补充量分别为1．65亿、1．61亿、0．82亿粒（尾）,呈下降趋势;2013年无早期资源补充。溪洛渡、向家坝2个梯级大坝一定程度上阻隔了圆口铜鱼卵苗向下游漂流的途径。要合理制定水电梯级调度方案,促进或引起圆口铜鱼自然繁殖过程,并降低圆口铜鱼卵苗在库区的死亡率;加强圆口铜鱼现有栖息地保护,严格控制或禁止在产卵场捕捞亲鱼;开展圆口铜鱼在梯级大坝上下游间群体交流连通性的可能性研究和圆口铜鱼全人工繁殖技术研究。     

Seagrass habitat reduces vulnerability of red sea bream <Emphasis Type="Italic">Pagrus major</Emphasis> juveniles to piscivorous fish predator

ABSTRACT:   Predation experiments were conducted in mesocosms to test the hypothesis that habitat complexity affects vulnerability of red sea bream Pagrus major juveniles to piscivorous fish predators. Juvenile behavior was video-recorded for 6 h in two structurally different habitats: vegetated with sea grass Zostera marina , and unvegetated 0.5-t tanks. Association behavior with seagrass was observed in the vegetated tank throughout the trials. Predation experiments were conducted with 30 red sea bream juveniles (29.9 mm body length) exposed to two individuals of the piscivorous fish predator Chinese sea bass Lateolabrax sp. (261.6 mm), for 6 h in 1.0-t tanks. Predation rate (no. of fish predated on per predator per h) was significantly lower in the vegetated tank (0.02/predator per h) than in the unvegetated tank (0.27/predator per h). Present experiments indicate that habitat complexity reduces vulnerability of juvenile red sea bream to predation by piscivorous fish by serving as physical and/or visual barriers and limiting the predator's ability to pursue and capture prey. Seagrass beds in the shallow coastal waters around Japan are suggested to be an important nursery for red sea bream since they provide the juveniles with habitat complexity as well as serve as a feeding ground.     

Predicting recruitment density dependence and intrinsic growth rate for all fishes worldwide using a data‐integrated life‐history model

Fisheries scientists use biological models to determine sustainable fishing rates and forecast future dynamics. These models require both life‐history parameters (mortality, maturity, growth) and stock‐recruit parameters (juvenile production). However, there has been little research to simultaneously predict life‐history and stock‐recruit parameters. I develop the first data‐integrated life‐history model, which extends a simple model of evolutionary dynamics to field measurements of life‐history parameters as well as historical records of spawning output and subsequent recruitment. This evolutionary model predicts recruitment productivity (steepness) and variability (variance and autocorrelation in recruitment deviations) as well as mortality, maturity, growth, and size, and uses these to predict intrinsic growth rate (r) for all described fishes. The model confirms previous analysis showing little correlation between steepness and either natural mortality or asymptotic maximum size (). However, it does reveal taxonomic patterns, where family Sebastidae has lower steepness () and Salmonidae has elevated steepness () relative to the prediction for bony fishes (class Actinopterygii, ). Similarly, genus Sebastes has growth rate (0.09) approaching that of several shark families (Lamniformes: 0.02; Carcharhiniformes: 0.02). A cross‐validation experiment confirms that the model is accurate, explains a substantial portion of variance (32%–67%), but generates standard errors that are somewhat too small. Predictive intervals are tighter for species than for higher‐level organizations (e.g. families), and predictions (including intervals) are available for all fishes worldwide in R package FishLife. I conclude by outlining how multivariate predictions of life‐history and stock‐recruit parameters could be useful for stock assessment, decision theory, ensemble modelling and strategic management.     

Life cycle of <Emphasis Type="Italic">Dilophus okamurae</Emphasis> (Phaeophyceae) and its associated invertebrate fauna in Onagawa Bay,Japan

ABSTRACT:   The life cycle of Dilophus okamurae and the associated benthic invertebrate fauna were studied monthly or bimonthly from June 1998 to September 1999 at a depth of 4–7 m in Onagawa Bay along the Pacific coast of north-eastern Honshu, Japan (38°28'N, 149°29'E). Dry biomass ranged from 230 g/m² in June to 10 g/m² in October. Sporophytes with tetrasporangia appeared during July to September 1998. Gametophytes with oogonia or antheridia were observed for the first time in May 1999 during observation. The absence of mature sporophytes in 1999 suggests that the life cycle is completed over two years. The sympatric gastropods Lirularia iridescens , Homalopoma sangrarense, Conotalopia minima and Cantharidus callichroa synchronized with seasonal changes in biomass of this algae. In contrast, Barleeia angustata and B. trifasciata fluctuated independently. The juvenile sea urchin Strongylocentrotus nudus appeared in the algal population starting in October at 0.7 mm mean test diameter at high density, and disappeared after March.     

Completion of the Pacific bluefin tuna Thunnus orientalis (Temminck et Schlegel) life cycle

Tuna aquaculture is currently dependent on the wild capture of juveniles for production. The development of hatchery technology for bluefin and other tunas would be a major step forward in improving sustainability of their aquaculture. The present study overviews the technology in the life cycle completion of the Pacific bluefin tuna (PBT) Thunnus orientalis (Temminck et Schlegel) under aquaculture conditions in Kinki University, and the problems to be solved for the establishment of tuna hatchery technology. On 23 June 2002, broodstock of PBT that were artificially hatched and reared spontaneously spawned in captivity. The resulting eggs hatched and were subsequently reared to the juvenile stage. The spawning fish were the result of a research project started in 1987 to rear wild‐caught juvenile PBT that were several months old. Fertilized eggs were obtained from these fish in 1995 and 1996. Resulting juveniles (the artificially hatched first generation) were reared to maturity and spawned in 2002. Over the summer of 2002, 1.63 million eggs from these fish were used for a mass rearing experiment, and 17 307 juveniles were produced and transferred to an open sea net cage. Of these artificially hatched second‐generation PBT, 1100 grew to approximately 95 cm total length and 14 kg body weight in 22 months. This procedure means the completion of PBT life cycle under aquaculture conditions, which was first attained among large tuna species. The problems awaiting solution in PBT hatchery production are their unpredictable spawning in captivity, to improve survival during the first 10 days post hatch, to reduce cannibalism in larval and juvenile stages, and to solve collision problem causing high mortality during the juvenile stage.     

长石莼（缘管浒苔）生活史的初步研究

摘要: 通过实验室培养观察,发现缘管浒苔的生活史包括单性生殖、无性生殖和有性生殖三种方式。单株培养时,发现有些配子体通过放散两鞭毛的配子完成单性生殖;有些孢子体通过放散两鞭毛或四鞭毛的中性游孢子进行无性生殖。同时,有性生殖则由配子体和孢子体相互交替完成;多株培养时,雌雄异体的配子体成熟后,分别放散两鞭毛的雌雄配子,雌雄配子接合成合子,合子进一步发育成孢子体,孢子体成熟后放散四鞭毛的游孢子,游孢子运动一段时间后固着,随后发育成配子体。缘管浒苔的生活史是单倍的配子体与二倍的孢子体相互交替的同形世代交替。在缘管浒苔的生活史中,无性生殖和单性生殖占有优势。因为不论是在无性生殖过程中的游孢子还是单性生殖过程中的配子,一经附着即可生长,无须经过有性生殖雌雄配子的接合过程,这就缩短了繁殖周期,加之配子囊和孢子囊放散配子和孢子的数量很大,在海况条件适宜的情况下,使缘管浒苔大量繁殖,从而可能成为“绿潮”的成因之一。     

贴近生活——大学生思想政治教育管理的紧迫呼唤

“贴近生活”已成为大学思想政治教育管理的迫切要求。要使大学生思想政治教育管理真正“贴近生活”,必须将教育管理的主体置于生活之中,在生活中寻找契机,使思想政治教育管理的目标贴近生活,实现现实化;使教育管理的方法融入生活,实现多样化．使教育管理的内容源于生活,实现具体化。将思想政治教育管理寓于日常生活中,发挥日常生活情境的教育功能,不断提高思想政治教育管理的针对性、实效性和吸引力、感染力。     

抗梅岭霉素和阿维菌素二斑叶螨种群生命力和繁殖力的研究

采用营养液培养的棉苗饲养二斑叶螨Tetranychus urticae Koch,用梅岭霉素、阿维菌素对其逐代进行抗性选育,至第9代,测定了两个抗性种群的抗性水平、生命力和繁殖力。结果表明:梅岭霉素抗性种群的抗性达7.9倍,其雌成螨寿命、产卵量、卵的孵化率和后代若螨成活率分别比对照增加54.08%、39.93%、6.57%和-15.44%。阿维菌素抗性种群的抗性达5.8倍,其雌成螨寿命、产卵量、卵的孵化率和后代若螨成活率分别比对照增加15.88%、10.87%、5.86%和-9.32%。由此发现梅岭霉素和阿维菌素对二斑叶螨的生长发育和繁殖有一定有利作用,抗性风险性较大,应引起重视。     

赤眼蜂实验种群生命表的编制与应用

利用以寄生变黑卵或仔代成蜂数量作为繁殖力估计等方法,编制了3种赤眼蜂在5种不同寄主卵上繁殖的实验种群生命表。分析比较表明,生命表参数能较好地反映“蜂-卵”组合的适合程度和寄生效能。初步认为,赤眼蜂实验种群生命表的编制,可以作为室内评估“蜂种与目标害虫”和“蜂种与中间寄主”的组合适合度和寄生效能的重要方法。其作用类似于农药的室内毒力测定。可供“育蜂治虫”实践参考。     

折带黄毒蛾生物学特性及综合防治

折带黄毒蛾在佳木斯地区1年1代,老熟幼虫在枯枝落叶及土缝中越冬。通过对折叠黄毒蛾生活习性和发生规律进行调查,分析其生物学特性,提出综合防治方法,为全面掌握折带黄毒夜蛾的发生规律与防治方法,为园林植保的可持续发展提供可靠的理论依据与技术支持。