COMPARATIVE STUDIES ON HATCHING OF ROTIFER RESTING EGGS IN THE SEDIMENTS OF DIFFERENT BASINS IN LAKE JINGHU

Abstract

Sediment samples from the two basins of Lake Jinghu were incubated at 10℃,20℃ and 30℃ to induce hatching of rotifer resting eggs.The emergent rotifers were identified and counted.47 rotifer species were identified,which belongs to 19 genera,10 families.40 species of rotifers were hatched from the sediments of big basin,and 41 species from the small basin of the lake.34 species of rotifers came from those of the two basins.On an average,1.1±0.1 and 0.4±0.0 rotifers were hatched from per milliliter sediments of the big and the small basins,respectively.The rotifer species,which was hatched at one incubation pattern from the resting eggs in sediments of both the two basins of the lake and whose density was higher than 20ind./200mL,included Proalides tentaculates,Anuraeopsis fissa,Keratella cochlearis,Brachionus diversicornis,Filinia brachiata and B.calyciflorus.With the three former species belonging to both the two basins of the lake,their emergence was different.The rotifer genera with higher densities (0.05ind./200mL) including Brachionus,Proalides,Keratella and Anuraeopsis were hatched from sediments of the samll basins.Beside of those genera,Filinia,Cephalodella and Trichocerca were also hatched from those of the big basin.The densities of Brachionus,Proalides and Keratella hatched from sediments of the big basin with more trophic were higher than those of the small basin with less trophic.