Abstract：【Abstract】 In this paper,the niche breadth and niche overlap of four unionicolid mites species parasitic in Cristaria plicata from Poyang areas were studied.The result indicated that the population of Unionicola arcuata in Cristaria plicata had the highest and the abundance was 20.26±50.00,while the population of U.ypsilophora had the lowest and the abundance was 0.29±1.28.U.arcuata and U.ypsilophora mainly distributed in the external gill,and the abundance were 9.0317±20.153 and 0.2063±0.975 4,respectively.U.penicillatus mainly distributed in the internal gill and the abundance was 0.6885±6.764.U.agilex mainly distributed in the foot and the abundance was 0.615 1±0.443 9.The temporal niche breath of U.arcuata was maximum and the value was 0.240 7,while the breath of U.agilex was minimum and the value was 0.099 6.U.penicillatus had the highest overlap in temporal niche with U.arcuata,and the value was 5.221 2;while U.penicillatus had no overlap in temporal niche with U.agilex.The spatial niche breath of U.agilex was maximum and the value was 0.526 7,while the breath of U.ypsilophora was minimum and the value was 0.287 8.U.arcuata had the highest overlap in spatial niche with U.ypsilophora,and the value was 2.649 4;while U.ypsilophora had the lowest overlap in temporal niche with U.agilex,and the value was 1.910 0.U.arcuata was found to have the maximum breadth of temporal-spatial niche and the value was 0.103 8,while U.agilex was found to have the minimum breadth and the value was 0.052 8.The temporal-spatial overlap value was the highest(11.598 9) between U.penicillatus and U.arcuata,and the lowest(0) between U.penicillatus and U.agilex.The resource competition might be absorbed in time for four unionicolid mites species in Cristaria plicata.After the long-term co-evolution,U.arcuata was found more suitable to living in Cristaria plicata,whereas U.penicillatus might compete with U.arcata.
2012, Vol. 36 
