淡水螺表型改变对食物量和食物类型变化的响应研究

发布时间：2024-01-23 16:36

　　生态保护和维持生物多样性越来越受到公众的关注。水生态系统是生态保护和维持生态多样性的重要领域。由于经济社会发展,污染物排放增加,造成水生态系统失衡,危及水生态系统平衡和生物多样性。生态保护和维持生物多样性是全球生态保护研究面临的紧迫问题。定量研究某一生态系统中特定物种的种内竞争表型改变和环境变化条件下物种生存繁衍是维持生态系统中的生物多样性的重要领域;相关的科学研究对水生态系统的修复与保护维持生物多样性具有重要的意义。本文研究对象是一种以鳃呼吸的淡水螺,隶属于平吻螺科,广泛分布于美国东南部。淡水螺作为水生态系统中初级消费者之一,对于生态食物网的能量传递以及水生态系统稳定有着至关重要的作用。特别是在水体富营养化中,有害藻类爆发会导致底栖生物的食物以及栖息地改变,改变其生活史以及表型变化,从而影响其生存;改变淡水螺食物网结构,对于其生物种群以及整个水生态系统稳定性都将造成影响。淡水螺食物供给水平是淡水螺种内竞争表型改变、体型变化的重要因素,特别是在高密度种群中。食物的变化不仅会使淡水螺种内竞争表型和体型改变,也会改变某些营养元素在淡水螺不同器官中的吸收和流动,从而影响淡水螺物种的生存和繁衍...

【文章页数】：64 页

【学位级别】：硕士

【文章目录】：
摘要
abstract
Chapter1.Introduction
    1.1 Interspecific competition and intraspecific competition of aquatic system
        1.1.1 natural competition introduction
        1.1.2 intraspecific competition dominant
    1.2 Freshwater snail competition
        1.2.1 consequence of freshwater snails’competition
        1.2.2 interspecific competition and intraspecific competition research cases of freshwater snails
        1.2.3 freshwater snails’competition mechanism from nutrient assimilation analysis
        1.2.4 Knowledge gap between previous studies and my research
    1.3 Isotope analysis and gastrointestinal tract content for species
        1.3.1 isotope analysis development and apply
        1.3.2 process and difficulties of isotope analysis in biotic samples
        1.3.3 gastrointestinal tract content apply
    1.4 Research significance and objectives
        1.4.1 significance for aquatic ecosystem
        1.4.2 objective of the field study
        1.4.3 objective of the lab control feeding
        1.4.4 objective of the isotope analysis
Chapter2.Methods
    2.1 Study area
    2.2 Study species
    2.3 Field study of freshwater snails with gradient density change
    2.4 Lab cultured experiment
    2.5 Stable isotope carbon and nitrogen process
        2.5.1 overall idea of stable isotope analysis
        2.5.2 pretreatment and key steps of stable isotope analysis
        2.5.3 models and calculation for stable isotope analysis
Chapter3.Result
    3.1 Field experiment
        3.1.1 abiotic parameters of the creek
        3.1.2 phenotype alterations and AFDM response to gradient freshwater snails’density change
        3.1.3 final individuals in14 experiment units(immigration)
        3.1.4 guts content in field freshwater snails’samples
    3.2 Lab culture phenotype result
        3.2.1 phenotype change in50 sampling days consequence
        3.2.2 correlations of length and weight in three groups
    3.3 Isotope analysis for carbon and nitrogen of freshwater snails’samples
        3.3.1 stable isotope nitrogen and carbon in freshwater snails’gonads and muscle
        3.3.2 transmitting rate(assimilation rate)of the body parts with different treatment..
Chapter4.Discussion
    4.1 Field result discussion
        4.1.1 phenotype change with increasing density
        4.1.2 AFDM(food quantity)response to increasing density
        4.1.3 conclusion to prove the hypothesis
        4.1.4 optimal freshwater snails’population density
        4.1.5 shortcoming for the field study
    4.2 Lab food control feed study
        4.2.1 our chosen food type and actual freshwater snails’guts food content
        4.2.2 nitrogen and carbon assimilation difference
        4.2.3 freshwater snails’life strategy response to food type change
        4.2.4 phenotype change to carbon and nitrogen turnover rate of the muscle parts
    4.3 Reliability of lab experiment analysis in our study
        4.3.1 isotope analysis errors
        4.3.2 gastrointestinal tract content errors
    4.4 Future study research
        4.4.1 perfection about my study
        4.4.2 my study involved with water pollution studies
Chapter5.Conclusion
Reference
Acknowledgement



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