Effect of Dissolved Oxygen, Temperature, Salinity, Ammonia-n and Nitrite-n on the Survivoal and Food Intake of CHARYBDIS FERIATUS
|School||Guangdong Ocean University|
|Keywords||Xiuban Charybdis Dissolved oxygen Temperature Salinity Ammonia Nitrite nitrogen Survival Photo bait|
In this study, as the research object Xiuban Charybdis, dissolved oxygen, temperature, salinity, ammonia and nitrite environmental factors on the survival of rust Charybdis photo bait. The resulting main findings are as follows: dissolved oxygen on the Charybdis of rust survival impact and proactive bait: 1 mg / L, temperature 23 ℃ ~ 27 ℃, salinity 30, pH values ??of 7.5 to 8.5 under the conditions set 2mg / L, 3 mg / L, 4mg / L, 5mg / L, 6mg / L 6 dissolved oxygen gradient, survival and feeding of dissolved oxygen on the rust Charybdis. The results showed that the dissolved oxygen concentration of 1mg / L, 2mg / L inappropriate Xiuban crab survival, the survival rate is very low, weak vitality, almost no feeding; 4mg / L ~ 6mg / L concentration of dissolved oxygen conditions, the camera Xiuban Charybdis bait There was no significant difference (p-gt; 0.05), with 1mg / L, 2mg / L concentration groups exist significantly with difference (p-lt; 0.05); 3mg / L of dissolved oxygen concentration, rust Charybdis of feeding rate and 4mg / L ~~ 6mg / L of dissolved oxygen concentration was no significant difference (p gt; 0.05), capable of feeding, but feeding rate is lower than the rust the Charybdis of feeding rate 4mg / L ~ 6mg / L of dissolved oxygen concentration. It showed that the 1 mg / L to 2mg / L concentration of dissolved oxygen conditions, low Xiuban the Charybdis camera bait rate, dissolved oxygen concentration of 4 mg / L ~ 6mg / L Xiuban crab feeding the appropriate dissolved oxygen, 3mg / L and 4mg / L concentration group was no significant difference 3mg / L of dissolved oxygen concentration is a turning point in the higher concentration, rust Charybdis feeding rate, below this concentration, the low rate of photo bait, dissolved oxygen concentration of 1mg / L, 2mg / L as inappropriate Xiuban the Charybdis feeding the dissolved oxygen. Temperature of rust crab survival and photo of the impact of the bait: salinity 30, pH values ??of 7.8 to 8.5, dissolved oxygen concentration of 6mg / L to 6.3 mg / L under the conditions, set 5 ° C, 10 ° C, 15 ° C, 20 ° C, 25 ℃, 30 ℃, 35 ℃, 40 ℃ 8 temperature gradient of the sudden changes in the test and gradient test. The results show that, under 5 ℃, 35 ℃ ~ 40 ℃ temperature conditions, the rust Charybdis high mortality and short survival time camera very low rate of bait; Xiuban crab survival rate at 10 ℃ ~ 30 ℃, the survival time long, especially under the conditions of 20 ℃ ~ 30 ℃, rust Charybdis camera the bait rate with other gradient exists a significant difference (p <0.05). It showed, 10 ℃ ~ 30 ℃ Xiuban crab can survive temperatures Xiuban Charybdis 20 ℃ ~ 30 ℃ for optimum temperature, 25 ℃ for its optimum temperature. Temperature of 22 ° C to 28 ° C, pH value of 7.5 to 8.5, dissolved oxygen concentration of 6mg / L to 6.3 mg / L under the conditions set 5,10,15,20,25,30,35,40,45,50 55 sudden change in salinity gradient test and gradient test. The results show that the sudden changes in the test, 20 to 40 salinity group long survival time difference with the other groups was significantly (p LT; 0.05). High survival rate of crab salinity of 20 to 35, there was no significant difference (p gt; 0.05), but with 15 bit salinity group salinity group 45 or more crab survival difference was significant (p lt; 0.05), and 40 salinity survival was no significant difference (p gt; 0.05). Salinity of 20 to 35, the photo of the rust crab bait rate higher salinity group with more than 40 and 15 bit salinity group significant differences (p lt; 0.05); 40 salinity salinity and 15 group and 45 the above salinity camera Bait Ratio also significant differences (p lt; 0.05); This shows that 20 to 40 Xiuban the Charybdis photo bait suitable salinity, from 25 to 35 for the camera bait is more appropriate salinity. The salinity group below 15, 45 or more salinity group photo bait salinity. 20 or less by the weight change of the rust Charybdis derived salinity group, salinity group, more than 40 within the salinity of 25 to 35 weight change does not exist a significant difference (p>; 0.05). Less weight change within 25 ~ 35 salinity, the salinity group with 20 or less, more than 40-salinity group there are significant differences (p LT; 0.05). Description: Salinity rust Charybdis weight is a minimum of 25 to 35. The impact of salinity on the survival of rust Charybdis photo bait: salinity gradient conditions for the survival rate of crab survival rate of 15 to 40 salinity group, a significant difference between groups with 50 or more salinity and the presence of 10 salinity group ( p lt; 0.05), with 45 salinity Group crab survival differences not significant (p gt; 0.05); survival time of 20 to 40 crabs survive for a long time, more than 50, less than 10 salinity group there are significant differences (p lt; 0.05), with 15 the salinity groups and 45 salinity group crab survival time difference is not significant (p gt; 0.05); bait uptake rate Photo Bait Ratio, 25 to 35 salinity conditions, with the other groups significant difference (p lt; 0.05), followed by 20 and 40 salinity, and the rest of the groups there are also significant differences (p lt; 0.05). Thus 5 to 15,50 to 55 is not taken the bait salinity, 20 to 45, 25 to 35 for photographic bait salinity the best photographic bait salinity. Ammonia on rust crab survival and photo bait: the temperature of 23 ° C to 28 ° C, salinity 30, pH values ??of 7.5 to 8.5, dissolved oxygen concentration of 6mg / L to 6.3 mg / L conditions set 0mg / L, 5 mg / L, 10 mg / L, 20mg / L, 40 mg / L, 80 mg / L and 160mg / L, a total of seven ammonia concentration gradient of ammonia on the rust crab survival and photographic bait impact test. The test results show that: the Charybdis the camera the bait rate and survival rate of rust under the condition of low concentration of ammonia nitrogen (0mg / L ~ 40mg / L), survived a long time, with a high concentration of ammonia nitrogen (80mg / L ~ 160mg / L) was significantly impact (p lt; 0.05), a comprehensive analysis found conducive far Xiuban Charybdis camera bait and survival ammonia concentration 0mg / L to 40 mg / L, the concentration of 80 mg / L to 160mg / L, rust the Charybdis photo baits reduced mortality. Survival and proactive bait the nitrite nitrogen rust Charybdis: at a temperature of 22 ° C to 27 ℃, salinity 30, pH values ??of 7.5 to 8.5, the concentration of dissolved oxygen 6mg / L ~~ 6.3 mg / L under the conditions, set 0mg / L, 10mg / L, 20mg / L, 40mg / L, 80mg / L, 160mg / L and 320mg / L of 7 nitrite nitrogen concentration gradient the nitrite nitrogen rust Charybdis survival and photo bait impact test. The test results show that: the camera bait and survival of rust Charybdis of nitrite nitrogen concentration has a significant impact 0mg / L ~ 40mg / L concentration, rust Charybdis camera the bait high rate, longer survival time, the survival rate was 100%, when the concentration of 80mg / L ~ 160mg / L, taken the bait low and high mortality.