Diet of two invading gobiid species (Proterorhinus semilunaris and Neogobius melanostomus) during the breeding and hatching season: No field evidence of extensive predation on fish eggs and fry     

《Limnologica》2014

One of the potential impacts of invasive gobies on native fish fauna is predation on eggs and fry. Therefore, the diet composition of two invading gobiid species, the tubenose goby Proterorhinus semilunaris and round goby Neogobius melanostomus, was examined in the Dyje river system (Danube basin, Central Europe) during the 2011 reproductive season to ascertain the extent of gobiid predation on heterospecific and conspecific eggs and juveniles. Consumption of fish eggs and juveniles by invading gobies was very low. The diets of both species consisted largely of benthic macroinvertebrates, and particularly insect larvae. These results indicate that invading gobies in the Dyje river system are likely to impact native fish fauna more through competitive effects than through direct predation on eggs and juveniles.  相似文献   

Seasonal changes in vertical distribution of zooplankton in an oligotrophic, subarctic lake (Lake Takvatn, Norway)     

Raul Primicerio   《Limnologica》2000,30(4):301-310

Zooplankton vertical distribution was studied in Lake Takvatn (69°07′ N) by discrete sampling of the water column during the open water season. Attention was focused on predation risk and competition to understand when, where and to what degree a given species should aggregate along the water column. Temperature profiles and phytoplankton abundance and composition were recorded to assess degree of heterogeneity and food availability in the pelagic zone. Vertical segregation was evident during thermal stratification. Rotifers partitioned the water column, with species less susceptible to predation (e.g. Conochilus unicornis) in the epilimnion, where they overlapped with the predators Asplanchna priodonta and Polyphemus pediculus, and species more vulnerable to these predators (e.g. Keratella cochlearis) in the hypolimnion. Cladocerans remained in the epilimnion, in a year when predation by fish was limited. The copepodites of Eudiaptomus graciloides and Cyclops scutifer maintained different depths staying respectively near surface and in the meta-hypolimnion. A broader distribution with increasing density was evident among rotifers and C. scutifer nauplii. Density-dependent habitat selection behaviour is considered as a mechanism explaining the observed distribution of predators and competing prey and promoting species coexistence.  相似文献   

Diel Vertical Migration of the Marine Cladoceran Podon Leuckarti: Variations with Reproductive Stage     

Hiroaki Saito  Hiroshi Hattori 《Journal of Oceanography》2000,56(2):153-160

Diel vertical migration (DVM) of the marine cladoceran Podon leuckarti was investigated with reference to their reproductive stages and size. Males and females, except for gamogenic females with an advanced resting egg (GA), aggregated at the near-bottom layer or at the surface during the day and dispersed into the water column at night. Both the near-bottom aggregation and the surface aggregation during daytime are suggested to be behavior that reduces the predation risk from visual predators. However, GA aggregated in the near-bottom layer during daytime and avoided the surface layer. The near-bottom aggregation might be more effective behavior for GAs to reduce risk of visual predation than the surface aggregation because of the conspicuous resting egg they carried. These results show that carrying an advanced resting egg influenced the DVM of P. leuckarti.  相似文献   

花鲈仔稚幼鱼的形态特征及其生态习性的研究   总被引：3，自引：0，他引：3  

竺俊全  李明云  邵全利  贾定武 《海洋科学》2000,24(12):38-42

对人工育苗条件下花鲈仔、稚、幼鱼发育过程中的形态特征变化及生态习性进行了观察,结果表明,孵后７～９日龄,卵黄囊消失;３６日龄左右,奇鳍膜开始分化;５６日龄左右,开始出现鳞片;８５日龄左右,鳞片覆盖全身。随着形态特征的变化,与之相适应的习性也发生了变化。  相似文献   

花尾胡椒鲷早期发育阶段的摄食与生长特性   总被引：18，自引：3，他引：15  

张雅芝  谢仰杰  张文生 《台湾海峡》2000,19(1):27-35

１９９８年４～６月份在集美大学水产学院海水育苗试验场对人工培育的花尾胡椒鲷早期发育阶段的摄食和生长特性进行分析。结果表明,在水温为２５℃时,仔鱼约经６０～７０h 左右开口摄食,开口饵料为经１２０目筛网过滤的褶皱臂尾轮虫,以后随着鱼体的生长,依次投喂卤虫无节幼体和桡足类。对３７２尾仔、幼鱼解剖观察结果,摄食率达９７．０％,摄食量占体重的６．４％～２３．４％,日摄食量占休重的２４．８％～８３．７％,摄取  相似文献   

渔港卸鱼码头合理泊位利用率研究   总被引：2，自引：0，他引：2  

桂劲松  李胜德 《海洋工程》2000,18(3):51-56

本文用计算机模拟方法计算出渔港缺卸鱼码头合理泊位利用率,可供渔港规划时参考。  相似文献   

Consumption of important pelagic fish and squid by predatory fish in the northeastern USA shelf ecosystem with some fishery comparisons   总被引：2，自引：1，他引：1  

Overholtz  W. J.; Link  J. S.; Suslowicz  L. E. 《ICES Journal of Marine Science》2000,57(4):1147-1159

  相似文献   

Feasibility of otolith markings in large juvenile turbot, Scophthalmus maximus, using immersion in alizarin-red S solutions   总被引：2，自引：0，他引：2  

Lagardere  F.; Thibaudeau  K.; Anras  M. L. Begout 《ICES Journal of Marine Science》2000,57(4):1175-1181

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沙蚕的营养分析与功能研究   总被引：13，自引：0，他引：13  

滕瑜  王印庚  王彩理 《海洋科学进展》2004,22(2):215-218

对2种双齿围沙蚕和国产鱼粉进行了营养组成分析。结果表明,2种双齿围沙蚕在营养构成上差别不大,只是在脂肪和灰分以及钙、铁上有差别;与国产鱼粉相比,在所测定的各种营养指标上,2种双齿围沙蚕的营养性超过国产鱼粉：其中呈味氨基酸超过高达5％左右,各种微量元素也相差较大。沙蚕的营养性、诱食性以及适口性均超过国产鱼粉。  相似文献   

新疆博斯腾湖浮游甲壳动物群落结构   总被引：3，自引：2，他引：1  

王松波  薛庆举  高光  汤祥明  陈源高  龚志军 《湖泊科学》2011,23(6):926-933

2010年6-11月和2011年1月,对博斯腾湖的浮游甲壳动物群落进行了调查,并分析了环境因子对其群落结构的影响.结果表明,不管是在种类数量,还是在密度和生物量上,浮游甲壳动物都主要由枝角类组成,且优势物种存在明显的季节变化.在夏季,浮游甲壳动物主要由大型的僧帽潘和短尾秀体溞组成;在秋冬季,随着大型种类现存量的减少,小...  相似文献