| The red swamp crayfish (procambarus clarkii) has become an important resource in the world’s freshwater shrimp farming because it is well appreciated by consumers for its delicious meat and nutritional value. In china and other foreign countries, crayfish have been a subject for many research reports. But the thorough study of the heavy metals effect on the growth and development of crayfish larvae and their surrounding environment and the relationship between heavy metal contents is still missing. In this thesis crayfish is used as a subject of research under laboratory studies to determine the Cd2+, Pb2+, Cu2+concentration on larval growth development and mortalities, analysis of the relationship between heavy metal ion concentration and its duration of action and within the enriched volume. Collection of crayfish samples from different regions as well as water and soil samples from the same region, determination of samples of Cd2+, Pb2+, Cu2+content in heavy metal pollution in lakes, rivers, rice fields, artificial ponds and other important water sources. Analysis of the relationship between ion concentration in crayfish body with water and soil ion concentration, to explore the main factors that affect crayfish in vivo accumulation of heavy metals, crayfish farming environment, water quality monitoring and pollution prevention and control to provide information. The main results showed that:1. In different Cd2+concentrations, no significant difference between juvenile crayfish growth parameters changes in the concentration (P>0.05) was found, but the growth of various morphological parameters of significant differences in concentration (P<0.05), the twice rapid growth period of the control group and the group of low concentration of juvenile crayfish, middle and high concentration group of juvenile crayfish were three and four times the rapid growth period, its rapid growth period are consistent with the molting time; mortality of juvenile crayfish tended to increase with increasing Cd2+concentrations, middle and high concentration group mortality were significantly higher than the individual of control group (P<0.05);juvenile crayfish enrichment of Cd2+increased with the increase of the concentration, juvenile crayfish high concentration group of Cd2+accumulation was significantly higher than the individual in control group (P<0.05).2. In different Pb2+concentrations, no significant difference between juvenile crayfish weight, body length, total length, carapace length and chela length growth parameters changes in the concentration (P>0.05), but juvenile crayfish abdomen length has a significant difference in the different concentration groups (P<0.05);growth rate of juvenile crayfish weight, body length, total length, carapace length, chela length and abdomen length showed the same trend, in concentration groups there were no significant differences (P>0.05);low concentration group, middle concentration group and high concentration group of juvenile crayfish mortalities were higher than that of control group (P<0.05), with the Pb2+concentration increase in the mortality of each concentration group showed rising trend, low concentration group, middle concentration group and high concentration group juvenile crayfish of Pb2+accumulation were significantly higher than the individual of control group (P<0.05).3. In different Cu2+concentrations, juvenile crayfish morphological parameters of growth of downward trend with increasing concentrations, the higher Cu2+concentration the stronger growth inhibition of juvenile crayfish; low concentration group, middle concentration group and high concentration group of juvenile crayfish mortalities were higher than that of control group (P<0.05);juvenile crayfish enrichment of Cu2+and Cu2+concentration has a positive correlation, low concentration group, middle concentration group and high concentration group juvenile crayfish of Cu2+accumulation were significantly higher than the individuals of control group (P<0.05).4. Significant differences of Cd2+, Pb2+, Cu2+soil contents of in the eight sampling intervals(P=0.000), rice region in Pei county, Xuzhou city and lack region in Pei county, Xuzhou city sampling the soil of Cd2+, Pb2+, Cu2+content were significantly higher than the other six regionals (P<0.05).5. Rice region in Pei county, Xuzhou city and lack region in Pei county, Xuzhou city water of Cd2+concentrations were highest, Cd2+concentrations were higher than river region in Dainan county, Taizhou city and river region in Jiangyan county, Taizhou city (P<0.05); no significant difference in the sampling interval of Pb2+content in waters (P>0.05); rice region in Pei county, Xuzhou city and river region in Dainan county,Taizhou city Cu2+concentrations in water with significant difference between artificial ponds region in Xinghua county,Taizhou city (P<0.05).6. Living in the four habitats crayfish body contents of Cd2+, Pb2+, Cu2+enrichment laws were as follows:Cd2+river> rice field>lake> artificial pond; Pb2+rice field>river> lake> artificial pond; Cu2+rice field> river> lake>artificial pond.7. Different tissues Cd2+accumulation were:hepatopancreas>abdominal muscle> shell> gills> foot muscle;different tissues as the law of Pb2+accumulation:shell> abdominal muscle> hepatopancreas> gills> foot muscle; different tissues as the law of Cu2+accumulation: abdominal muscle> hepatopancreas> gills> foot muscle> shell.That show hepatopancreas of Cd2+, Cu2+accumulation ability, shell higher accumulation of Pb2+, the lowest content of foot muscle.8. There was no significant difference between male and female individuals of different organizations of Cd2+, Pb2+, Cu2+content\(P>0.05).9. There were significant positive correlations between Cd2+and Pb2+content in soil and Cd2+and Pb2+content in water (P=0.000), but there was a no significant correlation between Cu2+content in soil and Cu2+content in water (P=0.560);there was a significant positive correlation between Cd2+and Pb2+content in soil and water and Cd2+and Pb2+content in whole crayfish individuals (P=0.000), but it was non-significant between Cu2+content in soil and water and Cu2+content in crayfish of the organizations.In summary:Cd2+, Pb2+, Cu2+have an impact on the growth and mortalities of crayfish of the Hormesis phenomenon, low heavy metals concentrations on juvenile crayfish growth has a promoting effect to a certain extent, the high concentrations of the resulting growth inhibition or even death. The ability of crayfish hepatopancreas, gills, foot muscle, abdominal muscle, shell organization to some extent, rich in Cd2+, Pb2+, Cu2+enrichment and heavy metal content in the habitat are closely related.All in all, the more heavy metals pollution in the environment, the more heavy metal concentrations in Crayfish. |
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