In present paper the genus Rhithrogena Eaton from Chinese mainland, including a new species to science (Rhithrogena lutea, sp. nov.), 2 new record species from China (R. bajkovae Sowa, R. lepnevae Brodsky) and 3 known...In present paper the genus Rhithrogena Eaton from Chinese mainland, including a new species to science (Rhithrogena lutea, sp. nov.), 2 new record species from China (R. bajkovae Sowa, R. lepnevae Brodsky) and 3 known species [R. wuyinensis (Gui et al.) (comb. nov.), R. trispina Zhou et Zheng, R. orientalis You (= R. sangangensis You, new synonym)] are revised besed on the imaginal specimens. A key to 7 species imagos is provided. All materials in this study are deposited in Nanjing Normal University.展开更多
Three new species of the genus Caenis (Ephemeroptera, Caenidae), Caenis aspera sp nov , Caenis bicornis sp nov and Caenis lubrica sp nov , are described from Hong Kong, China. All type specimens...Three new species of the genus Caenis (Ephemeroptera, Caenidae), Caenis aspera sp nov , Caenis bicornis sp nov and Caenis lubrica sp nov , are described from Hong Kong, China. All type specimens are deposited in the Insect Collection of Department of Entomology, South China Agricultural University, China.展开更多
Five species of the genus Caenis from Chinese mainland are reviewed. Among them, C. parviforcipis (Zhou et al.) (nov. comb.) is transferred from the genus Brachycercus The larvae of the C. sinensis Gui et al. are desc...Five species of the genus Caenis from Chinese mainland are reviewed. Among them, C. parviforcipis (Zhou et al.) (nov. comb.) is transferred from the genus Brachycercus The larvae of the C. sinensis Gui et al. are described for the first time. The previously reported C. nigroforceps Zhou et al. is recognized as a new synonym of the Caenis rivulorum Eaton, and the report of C. nigropunctata Klapálek from China is confirmed. Both imagos and larvae of a new species C. melanoleuca, sp. nov. are described and illustrated in detail.展开更多
From June 2003 to June 2004, an investigation on the life cycle, production and trophic basis of dominant species of macrozoobenthos community in a second-order river of the Hanjiang River basin, Hubei, China was card...From June 2003 to June 2004, an investigation on the life cycle, production and trophic basis of dominant species of macrozoobenthos community in a second-order river of the Hanjiang River basin, Hubei, China was carded out. The results showed that the dominant species Leptophlebia sp. and Ephemera sp. appeared to develop two generations per year, and there was a small overlap in the two generations of both species. The pupation of Leptophlebia sp. mainly occurred in autumn and winter, while pupation of Ephemera sp. mainly took place in summer and winter. The standing stocks of the Leptophlebia sp. population and Ephemera sp. population had two peaks in a year. The cohort production and cohort P/B ratio of the Leptophlebia sp. population estimated by size frequency method were 19.018 1 g/m^2.a and 5.7 respectively, while its annual production and P/B ratio were 38.036 2 g/m^2.a and 11.4. The cohort production and cohort P/B ratio of the Ephemera sp. population were 38.015 9 g/m^2.a and 5.9, while its annual production and P/B ratio were 76.031 8 g/m^2.a and 11.8.展开更多
Mayflies constitute a major part of macroinvertebrate biomass and production in Iotic ecosystems, and play an important role in material cycle and energy flow. There are more than 250 species of mayflies in rivers and...Mayflies constitute a major part of macroinvertebrate biomass and production in Iotic ecosystems, and play an important role in material cycle and energy flow. There are more than 250 species of mayflies in rivers and streams of China. In order to learn their ecological functions, an investigation on life cycle, production and trophic basis of dominant species of mayflies in a second-order branch of Hanjiang River basin, Hubei, China was carried out during June 2003 to June 2004. The results showed that the dominant mayfly species Epeorus sp. and Caenis sp. developed two generations per year; in term of Epeorus sp., pupation mainly occurred in spring and then from late summer to early autumn, while Caenis sp. pupated in spring and autumn. The abundance and biomass of the Epeorus sp. population peaked twice （1 226 ind/m^2, 3.142 5g/m^2） in April and June. Caenis sp. also had two peaks （307ind/m^2, 1.590 g/m^2）, but in February and June. Cohort production and cohort P/B ratio of Epeorus sp. were 161.009 g/m2 wet weight and 7.7, respectively, and annual production and P/B ratio were 267.46g/m^2.a wet weight and 15.4, respectively; cohort production and P/B ratio of Caenis sp. were 26.7995g/m^2 wet weight and 4.7, its annual production and P/B ratio were 53.60 g/m2.a wet weight and 9.4, respectively. For Epeorus sp., the proportions contributing to secondary production of the main food types were： amorphous detritus, 33.46%; fungi, 10.83%; vascular plant detritus, 1.80%; diatoms, 53.90%; for Caenis sp., the proportions were 70.79%, 6.90%, 3.52% and 18.77%, respectively.展开更多
The objectives of this research were to record the changes in composition of the community of ephemeroptera in Plalar-Gremeng river, examine the causes of these changes and discover their significance in the life of t...The objectives of this research were to record the changes in composition of the community of ephemeroptera in Plalar-Gremeng river, examine the causes of these changes and discover their significance in the life of the rivers. The ephemeropteran community and abundance of the feeding group （detritivore, gatherer and scrapper） were compared with the nutrient and water quality of each sampling site. It is established that, under site conditions, nutrient status can be regarded as the chief internal factors. The method was field survey for sampling the substrate at five sites： （I） Up-stream of Plalar river; （2） The site before the Plalar cave; （3） The total dark zone of Plalar-Gremeng caves; （4） The site after Gremeng cave and （5） The down-stream of Gremeng to Beton river. Substrate sampling used Surber benthic sampler and the sample was containing and labeling. Environmental parameters were measured water temperature, carbon dioxide, velocity, pH, C-organic, sediment total-phosphorus and nitrogen and Ca content. The data was analyzed by description. The results showed that the abundance of ephemeroptera was highest at site-4 and the lowest at site-3. Ephemeropthera play a highly important role in preserving nutrient status.展开更多
基金National Natural Sciences Foundation of China (30300037)
文摘In present paper the genus Rhithrogena Eaton from Chinese mainland, including a new species to science (Rhithrogena lutea, sp. nov.), 2 new record species from China (R. bajkovae Sowa, R. lepnevae Brodsky) and 3 known species [R. wuyinensis (Gui et al.) (comb. nov.), R. trispina Zhou et Zheng, R. orientalis You (= R. sangangensis You, new synonym)] are revised besed on the imaginal specimens. A key to 7 species imagos is provided. All materials in this study are deposited in Nanjing Normal University.
文摘Three new species of the genus Caenis (Ephemeroptera, Caenidae), Caenis aspera sp nov , Caenis bicornis sp nov and Caenis lubrica sp nov , are described from Hong Kong, China. All type specimens are deposited in the Insect Collection of Department of Entomology, South China Agricultural University, China.
文摘Five species of the genus Caenis from Chinese mainland are reviewed. Among them, C. parviforcipis (Zhou et al.) (nov. comb.) is transferred from the genus Brachycercus The larvae of the C. sinensis Gui et al. are described for the first time. The previously reported C. nigroforceps Zhou et al. is recognized as a new synonym of the Caenis rivulorum Eaton, and the report of C. nigropunctata Klapálek from China is confirmed. Both imagos and larvae of a new species C. melanoleuca, sp. nov. are described and illustrated in detail.
文摘From June 2003 to June 2004, an investigation on the life cycle, production and trophic basis of dominant species of macrozoobenthos community in a second-order river of the Hanjiang River basin, Hubei, China was carded out. The results showed that the dominant species Leptophlebia sp. and Ephemera sp. appeared to develop two generations per year, and there was a small overlap in the two generations of both species. The pupation of Leptophlebia sp. mainly occurred in autumn and winter, while pupation of Ephemera sp. mainly took place in summer and winter. The standing stocks of the Leptophlebia sp. population and Ephemera sp. population had two peaks in a year. The cohort production and cohort P/B ratio of the Leptophlebia sp. population estimated by size frequency method were 19.018 1 g/m^2.a and 5.7 respectively, while its annual production and P/B ratio were 38.036 2 g/m^2.a and 11.4. The cohort production and cohort P/B ratio of the Ephemera sp. population were 38.015 9 g/m^2.a and 5.9, while its annual production and P/B ratio were 76.031 8 g/m^2.a and 11.8.
文摘Mayflies constitute a major part of macroinvertebrate biomass and production in Iotic ecosystems, and play an important role in material cycle and energy flow. There are more than 250 species of mayflies in rivers and streams of China. In order to learn their ecological functions, an investigation on life cycle, production and trophic basis of dominant species of mayflies in a second-order branch of Hanjiang River basin, Hubei, China was carried out during June 2003 to June 2004. The results showed that the dominant mayfly species Epeorus sp. and Caenis sp. developed two generations per year; in term of Epeorus sp., pupation mainly occurred in spring and then from late summer to early autumn, while Caenis sp. pupated in spring and autumn. The abundance and biomass of the Epeorus sp. population peaked twice （1 226 ind/m^2, 3.142 5g/m^2） in April and June. Caenis sp. also had two peaks （307ind/m^2, 1.590 g/m^2）, but in February and June. Cohort production and cohort P/B ratio of Epeorus sp. were 161.009 g/m2 wet weight and 7.7, respectively, and annual production and P/B ratio were 267.46g/m^2.a wet weight and 15.4, respectively; cohort production and P/B ratio of Caenis sp. were 26.7995g/m^2 wet weight and 4.7, its annual production and P/B ratio were 53.60 g/m2.a wet weight and 9.4, respectively. For Epeorus sp., the proportions contributing to secondary production of the main food types were： amorphous detritus, 33.46%; fungi, 10.83%; vascular plant detritus, 1.80%; diatoms, 53.90%; for Caenis sp., the proportions were 70.79%, 6.90%, 3.52% and 18.77%, respectively.
文摘The objectives of this research were to record the changes in composition of the community of ephemeroptera in Plalar-Gremeng river, examine the causes of these changes and discover their significance in the life of the rivers. The ephemeropteran community and abundance of the feeding group （detritivore, gatherer and scrapper） were compared with the nutrient and water quality of each sampling site. It is established that, under site conditions, nutrient status can be regarded as the chief internal factors. The method was field survey for sampling the substrate at five sites： （I） Up-stream of Plalar river; （2） The site before the Plalar cave; （3） The total dark zone of Plalar-Gremeng caves; （4） The site after Gremeng cave and （5） The down-stream of Gremeng to Beton river. Substrate sampling used Surber benthic sampler and the sample was containing and labeling. Environmental parameters were measured water temperature, carbon dioxide, velocity, pH, C-organic, sediment total-phosphorus and nitrogen and Ca content. The data was analyzed by description. The results showed that the abundance of ephemeroptera was highest at site-4 and the lowest at site-3. Ephemeropthera play a highly important role in preserving nutrient status.
