| In the intensive cultivation of procambarus clarkii,the fingerlings is very critical,and the quality of fingerlings is determined by the cultivation process of procambarus clarkii.Different ecological factors have important effects on the growth and breeding of procambarus clarkii,such as temperature,light,water level and culture density,so this paper intends to take procambarus clarkii with body weight of 18g as the research object.Firstly,through the comparison of indoor culture conditions(different temperatures,different water levels and shelters),the optimal indoor culture ecological conditions of procambarus clarkii are determined to achieve high survival.The objective of survival rate is to study the effects of different densities on the growth and non-specific immunity of procambarus clarkii.Finally,when procambarus clarkii reached the peak of sexual maturity at the end of September,light period and intensity were selected to study the effects of light on the growth and breeding of procambarus clarkii under indoor conditions by means of orthogonal experiments to determine the breeding of procambarus clarkii.This paper put forward optimum ecological factors of indoor culture,reasonable methods of rearing and management of parent procambarus clarkii in indoor culture to provide scientific reference for large scale breeding of procambarus clarkii.The experimental results are as follows:1.Effects of Indoor Culture Conditions on the Growth and Survival of Procambarus ClarkiiAfter 35 days of culture,the growth and development of procambarus clarkii were accelerated with the increase of culture temperature.The growth rate and specific growth rate of procambarus clarkii reached the peak when the culture temperature was 25℃ and the survival rate decreased significantly when the temperature was raised to 28℃.The effect of comprehensive temperature on the growth and survival rate of procambarus clarkii was discussed.The optimum water temperature is 25℃.In other culture conditions,the water levels were 10cm,15cm and 20cm respectively.After 35 days of culture,the growth rate and specific growth rate of procambarus clarkii were not significantly affected by different water levels(P>0.05),and the survival rate of procambarus clarkii in the 15cm water level group was the highest among the three groups(P<0.05).The optimum water level is 15cm.In other culturing conditions,the shelters were "brick+integrated plastic cup","brick+integrated plastic cup+water weed(water hyacinth,water peanut)" and no shelter.After 35 days of cultivation,the order of weight gain,specific growth rate and survival rate of procambarus clarkii was "brick+integrated plastic cup" group>"brick+integrated plastic cup+water weed(water hyacinth,water flower)".The weight gain rate and specific growth rate of the shaded group were significantly higher than those of the control group(P<0.05).The survival rate of the brick+integrated plastic cup group was significantly higher than that of the control group.The survival rate of the other group was not significantly different from that of the control group(P>0.05).It is concluded that the most suitable shelter is "brick+integrated plastic cup".2.Effects of Density on Growth and Survival and Nonspecific Immunity of Procambarus ClarkiiThe effects of culture density of 10,15,20 and 25 procambarus clarkiis per square meter(expressed by D1,D2,D3 and D4 respectively)on the growth and survival of procambarus clarkii were studied.The results showed that the growth rate of body length,D1 group>D2 group>D3 group>D4 group,and significantly higher than that in D4 group(p<0.05).There was no significant difference among the former three groups;the weight gain rate and specific growth rate in D1 group>D2 group>D3 group>D4 group,and the growth rate in D1 group was significantly higher than that in D2 and D3 group,and that in D2 and D3 group was significantly higher than that in D4 group(p<0.05);the survival rate in D1 group and D3 group was not significantly different(p>0.05),and the survival rate in D1 group>D3 group was significantly higher than that in D4 group.The survival rate,D1 group>D2 group>D3 group>D4 group,and the former three groups were significantly larger than group D4(p<0.05),but there was no significant difference between group D2 and group D3(p>0.05).The activities of lysozyme and acid phosphatase in serum and hepatopancreas of procambarus clarkii proclaiming crustacean,D1 group>D2 group>D3 group>D4 group,and the activities of LZM and ACP in Di group were significantly higher than those in D2 and D3 group,D2 and D3 group were significantly higher than those in D4 group(p<0.05);the activities of alkaline phosphatase in serum and hepatopancreas were higher in Di and D2 group than those in D3 group,and D3 group was significantly larger than that in D4 group(p<0.05).The activity of catalase in D1 group was significantly higher than that in other three groups(p<0.05).There was no significant difference in the activity of catalase in hepatopancreas among the four groups(p>0.05).There was no significant difference in the activity of malondialdehyde in serum and hepatopancreas among the four groups(p>0.05).In conclusion,with the increase of culture density,the body length increment,body weight increment and survival rate of procambarus clarkii decreased significantly,and the immunity and disease resistance ability of procambarus clarkii decreased gradually.The optimum culture density was 20 per square meter.3.Effects of Light Period and Light Intensity on the Growth and Gonad Development of Female Procambarus ClarkiiAquaculture water temperature was 25℃,culture density was 20 per square meter,water level was 15cm,brick and integrated plastic cup were used as shelter.The experiment adopted two-factor and four-level cross-grouping without repetition.The light period A(8L:16D,12L:12D,16L:8D,20L:4D)and light intensity B(501x,2501x,5001x,10001x)were divided into 16 experimental groups.The effect of procambarus clarkii growth and gonad development.The survival rate of procambarus clarkii was significantly affected by light period and intensity(p<0.05).At the level of light period A3(16L:8D)and light intensity B2(250Lx),the maximum value was reached,and the light period had a significant effect on the growth rate of procambarus clarkii(P<0.05),the maximum value was reached at the light period A3(16L:8D),but the effect of light intensity on the weight gain rate was not significant(p>0.05);the effect of light period and light intensity on the hepatopancreas index was not significant(p>0.05).The most important factor affecting the growth of female procambarus clarkii is the light period,and next came the light intensity.The effects of light period and intensity on ovarian index of procambarus clarkii were significant(p<0.05).The order of survival rate of female procambarus clarkii in different light periods is obtained,A3>A2>A4>Ai.The order of survival rate of female procambarus clarkii in different light intensities was B3>B4>B1>B2.The gonad index of procambarus clarkii reached the maximum at the levels of light period A3(16L:8D)and light intensity B3(500Lx).According to the optimum level,the factors were A3 and B3.The most important factor affecting the gonad development of female procambarus clarkii is the light period,and next came the light intensity.After 50 days of culture period,eggs-bearing shrimp appeared in light period A3(16L:8D)and A4(20L:4D),which indicated that prolonging light period properly could accelerate the eggs-holding of procambarus clarkia.Considering the effects of above light periods and intensity on the growth and gonad development of procambarus clarkii,the optimum light intensity was 16L:8D and 250～500Lx. |
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