SPECIES COMPOSITION,SPATIAL DISTRIBUTION AND BIOMASS OF SHRIMP COMMUNITY IN THE BIANDANTANG LAKE

The species composition,spatial distribution and biomass of shrimps in the Biandantang Lake,Hubei province,were in-vestigated by sampling with pop-net (10m2) in the Autumn of 2002. The total of 44 287 individuals belonging to 6 species,5 gen-era and 2 families,were collected from the 31 sampling sites. The dominant species were Macrobrachium nipponense, Caridinanilotic gracilipes and Neocaridina denticulate sinensis,which contributed 99. 3 %to the total. In terms of water depth,the lake wasclassified into 3 water-depth areas: shallow area ( 1. 5m). Based onthe type and coverof aquaticvegetation,the lake was categorized into 4 habitat types: Vallisnerria spiralis habitat, Ceratophyllumdemersum habitat, Myriophyllum spicatum habitat,and naked habitat. For dominant shrimps,significant difference in density wasnot observed among 3 water-depth areas (ANCOV,P >0. 05) ; whereas,it was found among 4 habitat types (ANCOV, P 2and 3. 97 g/m2,respectively,of which C.nilotic gracilipes contributed 64. 69 ind/m2and1. 53 g/m2, M. nipponense 8. 99 ind/m2and 2. 09 g/m2,and N. denticulate sinensis 8. 61 ind/m2and 0. 22 g/m2.