We conducted experiments in an artificial stream tank with wild juvenile Chinese sturgeon Acipenser sinensis captured in the Yangtze Estuary to test the null hypothesis that their feeding efficiency on Barcheek goby R...We conducted experiments in an artificial stream tank with wild juvenile Chinese sturgeon Acipenser sinensis captured in the Yangtze Estuary to test the null hypothesis that their feeding efficiency on Barcheek goby Rhinogobius giurinus was not affected by sand vs. smooth glass substrate. Gobies are among the most common prey eaten by wild juvenile A. sinensis in the estuary. Test results found neither substrate type significantly affected feeding efficiency by juveniles. Previous research found a strong innate habitat preference of A. sinensis for sand substrate. The present results indicate that the preference for sand is not related to efficiently capturing R. giurinus on sand, but is an adaptation predisposing juvenile A. sinensis to seek sandy substrate where R. giurinus and other benthic forage are the most abundant in the Yangtze Estuary.展开更多
To understand the effects of sand grain size on habitat selection, we conducted a field study on the steppe toad-headed lizard in Hunshandake Desert northern China. Methods of mark-recapture and transect survey were u...To understand the effects of sand grain size on habitat selection, we conducted a field study on the steppe toad-headed lizard in Hunshandake Desert northern China. Methods of mark-recapture and transect survey were used to investigate the density of steppe toad-headed lizards and the environmental variables. The comparison on lizard densities among the habitats with different environmental factors revealed that： 1） population density of the steppe toad-headed lizard differed significantly among the habitats with different sand grain size indexes（SGSIs, representing roughness of sand substrate）： the highest lizard density was found in the group with an SGSI of 〉 0.30, whereas the lowest density was found in the group with an SGSI of 0–0.15; and 2） vegetation cover, soil moisture, invertebrate diversity index, and abundance had no significant effects on the lizard density. These results implied that the sand grain size was the most important determinant of habitat selection for steppe toad-headed lizards in Hunshandake Desert. Steppe toad-headed lizards could avoid structural habitats that have negative effects on their maximal sprinting capabilities. Considering the changing sand grain size in the development phase of sand dunes, the sand lizard could be used as an indicator of the process of desertification.展开更多
文摘We conducted experiments in an artificial stream tank with wild juvenile Chinese sturgeon Acipenser sinensis captured in the Yangtze Estuary to test the null hypothesis that their feeding efficiency on Barcheek goby Rhinogobius giurinus was not affected by sand vs. smooth glass substrate. Gobies are among the most common prey eaten by wild juvenile A. sinensis in the estuary. Test results found neither substrate type significantly affected feeding efficiency by juveniles. Previous research found a strong innate habitat preference of A. sinensis for sand substrate. The present results indicate that the preference for sand is not related to efficiently capturing R. giurinus on sand, but is an adaptation predisposing juvenile A. sinensis to seek sandy substrate where R. giurinus and other benthic forage are the most abundant in the Yangtze Estuary.
基金financial support of the Key Basic Science and Technology Project of the Ministry of Science and Technology, China (2013FY110300)the National Natural Science Foundation of China (No. 31572260)the Knowledge Innovation Project of the Chinese Academy of Sciences (KSCX2-EW-J-2)
文摘To understand the effects of sand grain size on habitat selection, we conducted a field study on the steppe toad-headed lizard in Hunshandake Desert northern China. Methods of mark-recapture and transect survey were used to investigate the density of steppe toad-headed lizards and the environmental variables. The comparison on lizard densities among the habitats with different environmental factors revealed that： 1） population density of the steppe toad-headed lizard differed significantly among the habitats with different sand grain size indexes（SGSIs, representing roughness of sand substrate）： the highest lizard density was found in the group with an SGSI of 〉 0.30, whereas the lowest density was found in the group with an SGSI of 0–0.15; and 2） vegetation cover, soil moisture, invertebrate diversity index, and abundance had no significant effects on the lizard density. These results implied that the sand grain size was the most important determinant of habitat selection for steppe toad-headed lizards in Hunshandake Desert. Steppe toad-headed lizards could avoid structural habitats that have negative effects on their maximal sprinting capabilities. Considering the changing sand grain size in the development phase of sand dunes, the sand lizard could be used as an indicator of the process of desertification.
