【作者】 王睿睿；

【导师】 关道明； 闫启仑；

【作者基本信息】 大连海事大学 ， 环境科学， 2009， 博士

【摘要】 端足类是海洋底栖生物的重要组成部分,是受人类活动影响,尤其对污染物质反应最敏感的底栖生物群落之一,对沉积物物理化学性质的耐受性较好,是沉积物毒性生物检测优选受试生物。河蜾赢蜚隶属于端足目钩虾亚目蜾赢蜚科蜾赢蜚属,做U型孔,栖息于潮间带软泥和泥沙底质,本文以其为实验生物,在实验室开展了多世代长期连续培养试验研究,并深入研究了f1和f2代的生活史、f1至f4代毒理敏感性及其变化规律,探讨了重金属对其毒性作用机制,主要研究内容与结果如下：1.通过生物学实验研究,掌握了河蜾赢蜚f1和f2代的生活史。研究了实验室培养条件下,河蜾赢蜚的生活周期、繁殖周期,确定了河蜾赢蜚的存活率、存活时间、性比、产幼体数量、繁殖数量、繁殖次数等。研究结果表明：河蜾赢蜚f1和f2代,雌性最长存活时间分别为190d、170d,雄性分别为100d、120d,雄性最长存活时间仅为雌性的一半左右；生活周期平均为64d、58d；幼体阶段性比分别为1：0.76、1：0.75(雌性：雄性)；雌性产幼体数量分别为13-28只幼体/雌体、11-27只幼体/雌体；雌性可连续繁殖5次；一生共产后代分别为64-149只幼体/雌体、81-127只幼体/雌体。2.通过加标镉的海水毒性实验,掌握了实验室恒温培养条件下河蜾赢蜚不同世代不同发育阶段的毒理敏感性变化规律。研究结果表明：河蜾赢蜚不同世代f1、f2、f3和f4代个体的毒理敏感性的变化规律为：f1到f2代个体的毒理敏感性逐渐增加,f2和f3代个体的毒理敏感性比较相近,而f4代个体的毒理敏感性又略有降低。f2和f3代个体适宜用于沉积物毒性检测中。河蜾赢蜚相同世代1、2和3周龄个体的毒理敏感性逐渐减弱,4周龄个体敏感性较3周龄要高,低于1和2周龄个体。结合生活史研究结果,建议在沉积物毒性检测中应选用2周龄个体。实验室培养个体的毒理敏感性与野生个体具有可比性。3.通过10 d加标镉沉积物毒性实验,研究了实验室恒温培养的f1、f2、f3和f4各世代2周龄个体及野生的2周龄个体的毒理敏感性。结果表明：河蜾赢蜚不同世代个体在加标沉积物中的半致死浓度分别为,291.673、261.857、215.792、306.459mg·kg-1,野生个体在加标沉积物中的半致死浓度为514.927 mg·kg-1；在加标沉积物中各世代毒理敏感性的变化规律与加标海水毒性实验中所得结果是一致的。野生的2周龄个体的毒理敏感性低于实验室培养个体。4.通过加标镉的海水毒性实验,研究了河蜾赢蜚生长、体内镉含量、抗氧化系统和脂质过氧化等在受镉胁迫时的变化规律。研究结果表明：随镉浓度升高,河蜾赢蜚死亡率增加,干重降低,存在较好的剂量-效应关系；河蜾赢蜚体内镉含量随海水中镉浓度的递增而增长；SOD活性随时间增加呈降低的趋势,随镉浓度增加呈增加-降低-增加的趋势；MDA含量随时间增加、随镉浓度增加呈抛物线型变化；MT含量随时间增加呈增加-降低-增加的趋势,随浓度增加而增加。干重和MT含量适宜作为毒性检测的终点指标。本文的实验结果表明河蜾赢蜚生活周期较短,易于实验室培养。实验室培养种群同野生一样,能准确反应沾污沉积物毒性。河蜾赢蜚是较理想的沉积物毒性检测的受试生物。本文研究成果将为该受试生物大量培养和广泛应用奠定科学基础,将极大地促进我国沉积物毒性生物检测工作向业务化方向迈进的进程。更多还原

【Abstract】 Amphipods are ecologically important members of benthic infaunal communities and are one of the most sensitive members among benthic communities to anthropogenic disturbance, especially to pollution. They are tolerant to varying sediment physicochemical characteristics and are ideal testing organisms for sediment toxicity test. Corophium acherusicum in this study is a corophiid amphipod species, builds a U-shaped tube in sediments ranging from coarse sand to silty clay in the intertidal zone. The multi-generation cultivation system of C. acherusicum has established under the constant temperature in the laboratory. The life history and the toxicity sensitivity C. acherusicum were studied in this paper. The main results are listed as follows:1. C.acherusicum was cultured in laboratory at 20℃. The life-cycle and reproduction-cycle tests of the first and second generation C.acherusicum were carried out in order to determine survival, sex ratio, number of juveniles per female, the total number of offspring, reproduction frequency. The results showed that the longest survival time of the first generation female was 190d, the second generation was 170d; the longest survival time of the first generation male was 100d, the second generation 120d; the longest survival time of male was only about half of the female; the life cycle of the first and second generation were respectively 64d,58d; the sex ratio of the first and second generation juveniles were respectively 1:0.76,1:0.75 (females:males); number of juveniles per female were respectively 13-28 juveniles/female,11-27 juveniles/female; C.acherusicum reproduction at least 5 times; the first and second generation C.acherusicum produced offspring 64-149 juveniles/female,81-127 juveniles/female respectively.2. The cadmium-spiking water-only toxicity tests were carried out in order to determine the toxic sensitivity change rule of different generations and each phase in its whole life of C. acherusicum. The toxic sensitivity of C. acherusicum from f1、f2、f3、f4 generation were:f1 generation juveniles were less sensitive than f2 generation;f2 generation juveniles were near sensitive than f3 generation and more sensitive than f4 generation. f2 generation and f3 generation are amenable to the toxicity test. The results showed that the toxic sensitivity of C.acherusicum gradually weakened from one-week juveniles、two-week juveniles to three-week juveniles. Four-week juveniles were more sensitive than three-week juveniles, less than one-week and two-week juveniles. Considering life history research results, this study suggests that two-week juveniles are amenable to the toxicity test. Toxicity sensitivity of lab cultured C.acherusicum was comparable to those of field collected C.acherusicum in toxicity test.3. The 10-d sediment toxicity test has been developed with cadmium-spiked sediment using two-week juveniles of lab cultured f1, f2, f3, f4 generation and field collected of C.acherusicum. The LC50 values of f1, f2, f3, f4 generation C.acherusicum were 291.673、261.857、215.792、306.459 mg·kg-1 respectively. The LC50 values of field collected of C.acherusicum was 514.927 mg·kg-1.The toxic sensitivity change rule of different generations in spiked sediment test was coincident with the rule of C.acherusicum in spiked water test. C.acherusicum cultured in lab was more sensitive than that of collected in field.4. The effects of cadmium on the growth, antioxidant defense system and lipid peroxidation in C.acherusicum were investigated with cadmium-spiked poor water toxicity test. Dry weight and survival of C.acherusicum decreased in accordance with the increase of metal ions concentrations. The contents of cadmium in C.acherusicum were elevated with the increasing concentration of cadmium and the prolonged time. The SOD activities were decreased with the prolonged time. The SOD activities were increased at a low concentration of cadmium, the activity was decreased at intermediate concentration of cadmium, while the activity was increased at high concentration. The MDA activity showed a parabola trend with the increasing concentration of cadmium and the prolonged time. The MT content were increased at preliminary of exposure test, the content was decreased at intermediate of exposure test, while the content was increased at late of exposure test. The dry weigh and MT activity are more suitable to be the end point for toxicity test.Results from a variety of experiments in this study indicate that C.acherusicum has a relatively short life-cycle and is easy to be cultured in laboratory. In addition, C.acherusicum cultured in lab is sensitive to the toxicity of sediment as well as that of field collected. In conclusion, C.acherusicum is an ideal testing organism for sediment toxicity test. The results of this study indicate that more and more C.acherusicum will be cultured in lab and used in the sediment toxicity test later.更多还原