【作者】 张珏；

【导师】 廖永岩；

【作者基本信息】 广东海洋大学 ， 海洋生物， 2010， 硕士

【摘要】 本研究以锈斑蟳为研究对象,研究了溶解氧、温度、盐度、氨氮以及亚硝氮等环境因子对锈斑蟳存活及摄饵的影响。所得主要研究结果如下:溶解氧对锈斑蟳存活和摄饵的影响:在温度23℃~27℃、盐度30、pH值7.5~8.5的条件下,设置1mg/L、2mg/L、3mg/L、4mg/L、5mg/L、6mg/L共6个溶解氧梯度,进行溶解氧对锈斑蟳存活和摄食影响的研究。结果表明,溶解氧浓度1mg/L、2mg/L不适宜锈斑蟳生存,存活率极低,活力弱,几乎不摄食;在4mg/L~6mg/L溶解氧浓度条件下,锈斑蟳的摄饵率无显著差异(p>0.05),与1mg/L、2mg/L浓度组存在显著差异(p<0.05);在3mg/L溶解氧浓度下,锈斑蟳的摄食率与4mg/L~6mg/L溶解氧浓度组无显著差异(p>0.05),能够摄食,但摄食率低于4mg/L~6mg/L溶解氧浓度下锈斑蟳的摄食率。由此说明,1mg/L~2mg/L溶解氧浓度条件下,锈斑蟳的摄饵率极低,溶解氧浓度4mg/L~6mg/L是锈斑蟳摄食的适宜溶解氧,3mg/L与4mg/L以上浓度组都无明显差异,说明3mg/L溶解氧浓度是一个转折点,高于此浓度,锈斑蟳的摄食率高,低于此浓度,则摄饵率偏低,溶解氧浓度1mg/L、2mg/L为锈斑蟳摄食的不适宜溶解氧。温度对锈斑蟳存活和摄饵的影响:在盐度30、pH值7.8~8.5、溶解氧浓度6mg/L~6.3mg/L的条件下,设置5℃、10℃、15℃、20℃、25℃、30℃、35℃、40℃共8个温度梯度分别进行骤变试验和渐变试验。结果表明,在5℃、35℃~40℃的温度条件下,锈斑蟳死亡率高,存活时间短,摄饵率极低;而锈斑蟳在10℃~30℃时的存活率高,存活时间长,尤其在20℃~30℃条件下,锈斑蟳的摄饵率与其他梯度存在显著差异(p﹤0.05)。由此说明,10℃~30℃为锈斑蟳的可存活温度,锈斑蟳 20℃~30℃为其适宜温度,25℃为其最适温度。在温度22℃~28℃、pH值7.5~8.5、溶解氧浓度6mg/L~6.3mg/L的条件下,设置5、10、15、20、25、30、35、40、45、50和55个盐度梯度进行骤变试验和渐变试验。结果表明,在骤变试验中,20~40盐度组的存活时间长,与其他组差异显著(p<0.05)。20~35盐度下的蟹存活率高,没有显著差异(p>0.05),但与15一下盐度组、45以上盐度组的蟹存活率差异显著(p<0.05),与40盐度下存活率没有显著差异(p>0.05)。盐度20~35下,锈斑蟳的摄饵率较高,与40以上盐度组,15一下盐度组有显著的差异(p<0.05);40盐度与15以下盐度组和45以上盐度组的摄饵率也有显著差异(p<0.05);这说明,20~40为锈斑蟳摄饵的适宜盐度,25~35为摄饵的较适宜盐度。而15以下盐度组,45以上盐度组为不适摄饵盐度。通过对锈斑蟳体重变化得出,20以下盐度组、40以上盐度组、25~35盐度内的体重变化都不存在显著差异(p>0.05)。而25~35盐度内的体重变化较少,而且与20以下盐度组、40以上盐度组都存在显著差异(p<0.05)。说明:盐度对锈斑蟳体重的影响在25~35内是最少的。盐度对锈斑蟳存活和摄饵的影响:在盐度渐变条件下,对于成活率,15~40盐度组蟹存活率高,与50以上盐度组和10以下盐度组存在显著差异(p<0.05),与45盐度组蟹存活率差异不显著(p>0.05);对于存活时间,20~40蟹存活时间长,与50以上、10以下盐度组存在显著差异(p<0.05),与15盐度组和45盐度组蟹的存活时间差异不显著(p>0.05);对于摄饵率,25~35盐度条件下摄饵率高,与其他各组差异显著(p<0.05),20和40盐度次之,与其余各组也存在显著差异(p<0.05)。由此可见5~15、50~55为不摄饵盐度,20~45为可摄饵盐度,25~35为最佳摄饵盐度。氨氮对锈斑蟳存活和摄饵的影响:在温度23℃~28℃、盐度30、pH值7.5~8.5、溶解氧浓度6mg/L~6.3mg/L的条件下,设置了0mg/L、5mg/L、10mg/L、20mg/L、40mg/L、80mg/L和160mg/L共7个氨氮浓度梯度进行氨氮对锈斑蟳存活及摄饵影响的试验。试验结果表明:低浓度氨氮(0mg/L~40mg/L)条件下的锈斑蟳的摄饵率和存活率高、存活时间长,与高浓度氨氮(80mg/L~160mg/L)有显著的影响(p<0.05),综合分析发现,在氨氮浓度0mg/L~40mg/L,利于远锈斑蟳的摄饵和存活,80mg/L~160mg/L浓度时,锈斑蟳摄饵量降低,死亡率升高。亚硝酸盐氮对锈斑蟳存活和摄饵的影响:在温度22℃~27℃、盐度30、pH值7.5~8.5、溶解氧浓度6mg/L~6.3mg/L的条件下,设置0mg/L、10mg/L、20mg/L、40mg/L、80mg/L、160mg/L和320mg/L共7个亚硝酸盐氮浓度梯度进行亚硝酸盐氮对锈斑蟳存活及摄饵影响的试验。试验结果表明:不同亚硝酸盐氮浓度对锈斑蟳的摄饵和存活都有显著的影响,在0mg/L~40mg/L浓度时,锈斑蟳的摄饵率高,存活时间长,成活率为100%,当浓度达到80mg/L~160mg/L时,摄饵率低,死亡率高。更多还原

【Abstract】 In this study, the effects of dissolved oxygen, temperature, salinity, ammonia-N and nitrite on the survival and food intake of Charybdis feriatus are investigated, all the results are as following.Effects of dissolved oxygen on the survival and food intake of Charybdis feriatus: Under the conditions of temperature of 23℃~27℃, salinity of 30 and pH 7.5~8.5, we put the Charybdis feriatus into seawater with different dissolved oxygen(DO) concentrations(1mg/L~6mg/L), to identify the effect of the DO concentration in seawater on the survival and food intake. The results are as following: The DO cocentration of 1mg/L and 2 mg/L is not suitable for Charybdis feriatus as it shows a low chance of survival, weak vatality and low food intake rate. Under the DO concentration of 4mg/L~6mg/L, the survivorship has no significant difference (p>0.05), but the significant difference appears when the DO concentration is 1mg/L~2 mg/L (p<0.05). The food intake rate of the DO cocentration of 3mg/L is lower than that of the DO concentration of 4mg/L~6mg/L.However, there is not significant difference with between them (p>0.05). The results suggest that the DO cocentration of 3mg/L is a milestones. Above this concentration , the crab shows a higher survival rate and food intake rate, while below this concentration both rates begin to go down. Thus the optimal concentration of DO for the crab to survive and food intake should be higher than 3mg/L.Effects of temperature on the survival and food intake of Charybdis feriatus: Under the conditions of salinity of 30, pH 7.5~8.5 and DO of 6mg/L~6.3mg/L, we put the Charybdis feriatus into seawater with different temperature (5℃、10℃、15℃、20℃、25℃、30℃、35℃and 40℃), to identify the effect of quick and gradual temperature change on survival and food intake. The results are as following: Crabs show the highest mortality, shortest survival time and lowest food intake rate at the temperature of 5℃and below or at 35℃and above. Within the temperature of 10℃~30℃, crabs show higher survival rate and longer survival time. Especially within the temperature of 20℃~30℃, crabs show the highest food intake rate which has a significant difference with other group (p<0.05). The results suggest that crabs can survive within the temperature of 10℃~30℃. The temperature of 20℃~30℃is viable for the crabs, and the optimal temperature is 25℃.Effects of salinity on the survival and food intake of Charybdis feriatus: Under the conditions of temperature of 22℃~28℃, pH7.5-8.5 and DO of 6mg/L~6.3mg/L, we put the Charybdis feriatus into seawater with different sanility (5、10、15、20、25、30、35、40、45、50 and 55) , to identify the effect of quick and gradual salinity change on survival and food intake of the crabs. The results are as following:With a quick salinity change, the survival time of Charybdis feriatus is the longest at salinity levels 20~40 which has a significant difference with other group (p<0.05). With a quick salinity change, the survival rate of Charybdis feriatus is the highest at salinity levels 20~35 which has a significant difference with salinity levels 15 and below or 45 and above (p<0.05), while has no significant difference with salinity levels 40 (p>0.05). There is a significant difference between salinity levels 40 and above or 15 and below with salinity levels 20~35, that thelatter group has a higher food intake rate (p<0.05). There is a significant difference between salinity levels 45 above and 15 below with salinity levels 40 (p<0.05). The results suggest that salinity levels 20~40 is suitable for the crabs food intake. The crabs are fed best at salinity 25~35. The result about the change of weight suggests that: There is a significant difference between salinity levels 40 and above or 20 and below with salinity levels 25~35 which has a lower change of weight (p<0.05).With a gradual salinity change, the survival rate of Charybdis feriatus is the highest at salinity levels 25~40 which has a significant difference with salinity levels 10 and below or 50 and above (p<0.05), but has no significant difference with salinity levels 45 (p>0.05). The survival time of Charybdis feriatus is the highest at salinity levels 20~40 which has a significant difference with salinity levels 10 and below or 50 and above (p<0.05), but has no significant difference with salinity levels 15 and 45 (p>0.05). The crabs are fed best at salinity 25~35 which has a significant difference with other salinity levels. The results suggest that salinity levels 20~45 is suitable for the crabs food intake. The crab are fed best at salinity 25~35.Effects of ammonia-N on the survival and food intake of Charybdis feriatus: Under the conditions of temperature of 23℃~28℃, salinity of 30, pH 7.5~8.5 and dissolved oxygen of 6mg/L~6.3mg/L, we put the Charybdis feriatus into seawater with different concentration of ammonia-N (0mg/L、5mg/L、10mg/L、20mg/L、40mg/L、80mg/L and 160mg/L), to identify the effects of the ammonia-N concentration in seawater on the survival and food intake. The results are as following: Under low concentration group of ammonia-N (0mg/L~40mg/L), crabs show high food intake rate , survivorship and long survival time which has a significant difference with high concentration group of ammonia-N (80mg/L~160mg/L) (p<0.05). The result suggests that the optimal concentration of ammonia-N for the crab to survive and to have a positive food intake rate should be lower than 40mg/L. Crabs show lower food intake rate and higher mortality when the concentration group of ammonia-N exceed 80mg/L.Effects of nitrite-N on the survival and food intake of Charybdis feriatus: Under the conditions of temperature of 22℃~27℃, salinity of 30, pH7.5~8.5 and DO of 6mg/L~6.3mg/L, we put the Charybdis feriatus into seawater with different concentration of nitrite-N (0mg/L、10mg/L、20mg/L、40mg/L、80mg/L、160mg/L and 320mg/L), to identify the effect of the nitrite concentration in seawater on the survival and food intake rate. The results are as following: Different concentrations of nitrite have significant difference on the food intake rate and survivoship.The best condition for food intake and survival is at the concentration of nitrite 0mg/L~40mg/L. When exceeding the concentration of nitrite 80mg/L, crabs show lower food intake rate and higher mortality.更多还原