Using a standard cytochrome c oxidase I sequence,DNA barcoding has been shown to be effective to distinguish known species and to discover cryptic species. Here we assessed the efficiency of DNA barcoding for the amph...Using a standard cytochrome c oxidase I sequence,DNA barcoding has been shown to be effective to distinguish known species and to discover cryptic species. Here we assessed the efficiency of DNA barcoding for the amphipod genus Gammarus from China. The maximum intraspecific divergence for widespread species,Gammarus lacustris,was 3.5%,and mean interspecific divergence reached 21.9%. We presented a conservative benchmark for determining provisional species using maximum intraspecific divergence of Gammarus lacustris. Thirty-one species possessed distinct barcode clusters. Two species were comprised of highly divergent clades with strong neighbor-joining bootstrap values,and likely indicated the presence of cryptic species. Although DNA barcoding is effective,future identification of species of Gammarus should incorporate DNA barcoding and morphological detection.展开更多
The aim of presented study was to determine the behavioural response of precopulatory pairs of Gammarus tigrinus exposed to the 17α-ethinylestradiol （EE2）. It was hypothesized that 17α-ethinylestradiol would incre...The aim of presented study was to determine the behavioural response of precopulatory pairs of Gammarus tigrinus exposed to the 17α-ethinylestradiol （EE2）. It was hypothesized that 17α-ethinylestradiol would increase the time needed for a male to re-capture a female. Hypothesis was tested in a laboratory with 20 precopula pairs exposed to different treatment conditions. Paired animals were exposed to two different compound concentrations of 50 ng·L-1 and 500 ng·L-1. The control and solvent control was artificial sea water and artificial sea water with ethanol （the diluent for EE2）. The couples were tested several times under different experimental treatments. The obtained results indicate that EE2 affects the precopulatory mate guarding behaviour of Gammarus tigrinus. EE2 in concentration of 50 ng·L-1 and 500 ng·L-1 prolonged the time needed for re-pairing. However, relative to the controls only EE2 in concentration of 500 ng·L-1 significantly prolonged the time needed for male-female re-coupling. In summary, EE2 affects the reproductive behaviour of Gammarus tigrinus.展开更多
Gammarids are important members of a stream’s macrozoobenthos biocoenosis and food web. Moreover, they proved to be very sensitive towards different types of pollution. GamToxTM is a new in situ ecotoxicity test, bas...Gammarids are important members of a stream’s macrozoobenthos biocoenosis and food web. Moreover, they proved to be very sensitive towards different types of pollution. GamToxTM is a new in situ ecotoxicity test, based on survival and feeding behavior of caged gammarids for active monitoring of small streams in agricultural areas. GamToxTM has been applied in two streams with specific pollution problems in the catchment of Lake Constance. Ten organisms were exposed in 5 replicates in flow through test tubes containing one conditioned alder leaf, placed in baskets which were attached in the stream bottom and on the banks. Each week, the number of living animals was counted, the percentage of leaf skeletized estimated in semi-quantitative classes and a new elder leaf provided. Dead organisms were removed. Simultaneously, chemical analyses of pesticides and nutrients (N-compounds, P) were performed on cumulative water samples over one week. Moreover, macrozoobenthos was collected and determined according to the IBCH method, and the SPEAR index calculated. GamToxTM proved to be very sensitive to detect pesticides, copper as well as nutrients, both during acute pollution pulses and chronic exposures of up to 6 weeks. Survival turned out to be a more sensitive and less variable parameter than feeding. GamToxTM is easy to perform and directly provides a measure of ecotoxicological effects of toxicant/nutrient mixtures, which cannot be predicted by biological indices based on macrozoobenthos data such as IBCH and SPEAR-index. This study was co-financed by the InterReg IV project “?kotoxikologischer Index im Bodenseeraum”, no. 227 (2011-2013) supported by the EFRE.展开更多
基金supported by the National Natural Sciences Foundation of China (NSFC-30499341/30770268/30870473)Beijing Financial Budget Index (2008-NO.0178)the Beijing Natural Science Foundation (5082013)
文摘Using a standard cytochrome c oxidase I sequence,DNA barcoding has been shown to be effective to distinguish known species and to discover cryptic species. Here we assessed the efficiency of DNA barcoding for the amphipod genus Gammarus from China. The maximum intraspecific divergence for widespread species,Gammarus lacustris,was 3.5%,and mean interspecific divergence reached 21.9%. We presented a conservative benchmark for determining provisional species using maximum intraspecific divergence of Gammarus lacustris. Thirty-one species possessed distinct barcode clusters. Two species were comprised of highly divergent clades with strong neighbor-joining bootstrap values,and likely indicated the presence of cryptic species. Although DNA barcoding is effective,future identification of species of Gammarus should incorporate DNA barcoding and morphological detection.
文摘The aim of presented study was to determine the behavioural response of precopulatory pairs of Gammarus tigrinus exposed to the 17α-ethinylestradiol （EE2）. It was hypothesized that 17α-ethinylestradiol would increase the time needed for a male to re-capture a female. Hypothesis was tested in a laboratory with 20 precopula pairs exposed to different treatment conditions. Paired animals were exposed to two different compound concentrations of 50 ng·L-1 and 500 ng·L-1. The control and solvent control was artificial sea water and artificial sea water with ethanol （the diluent for EE2）. The couples were tested several times under different experimental treatments. The obtained results indicate that EE2 affects the precopulatory mate guarding behaviour of Gammarus tigrinus. EE2 in concentration of 50 ng·L-1 and 500 ng·L-1 prolonged the time needed for re-pairing. However, relative to the controls only EE2 in concentration of 500 ng·L-1 significantly prolonged the time needed for male-female re-coupling. In summary, EE2 affects the reproductive behaviour of Gammarus tigrinus.
文摘Gammarids are important members of a stream’s macrozoobenthos biocoenosis and food web. Moreover, they proved to be very sensitive towards different types of pollution. GamToxTM is a new in situ ecotoxicity test, based on survival and feeding behavior of caged gammarids for active monitoring of small streams in agricultural areas. GamToxTM has been applied in two streams with specific pollution problems in the catchment of Lake Constance. Ten organisms were exposed in 5 replicates in flow through test tubes containing one conditioned alder leaf, placed in baskets which were attached in the stream bottom and on the banks. Each week, the number of living animals was counted, the percentage of leaf skeletized estimated in semi-quantitative classes and a new elder leaf provided. Dead organisms were removed. Simultaneously, chemical analyses of pesticides and nutrients (N-compounds, P) were performed on cumulative water samples over one week. Moreover, macrozoobenthos was collected and determined according to the IBCH method, and the SPEAR index calculated. GamToxTM proved to be very sensitive to detect pesticides, copper as well as nutrients, both during acute pollution pulses and chronic exposures of up to 6 weeks. Survival turned out to be a more sensitive and less variable parameter than feeding. GamToxTM is easy to perform and directly provides a measure of ecotoxicological effects of toxicant/nutrient mixtures, which cannot be predicted by biological indices based on macrozoobenthos data such as IBCH and SPEAR-index. This study was co-financed by the InterReg IV project “?kotoxikologischer Index im Bodenseeraum”, no. 227 (2011-2013) supported by the EFRE.
