Chinese alligator hatchlings in captivity are fragile and have a high mortality rate within first year.The body mass gain of reptile animals is closely related to their feeding behavior and gut microbiota.This study a...Chinese alligator hatchlings in captivity are fragile and have a high mortality rate within first year.The body mass gain of reptile animals is closely related to their feeding behavior and gut microbiota.This study analyzed the intrinsic factors influencing the allometric growth of Chinese alligator hatchlings based on their body mass gain,feeding behavior,and gut microbiota.This information would enhance the health management of Chinese alligator hatchlings.There was a significant correlation between the total distance moved,the average number of conspecifics nearby,and body mass gain.Chinese alligator hatchlings with a greater growth rate showed greater activity and more independent behavior during feeding than those with a lower growth rate.Moreover,after feeding started,some functions of the gut microbiota showed significant relationships with growth rate and feeding activity.Chinese alligator hatchlings with a greater growth rate showed greater levels of heme biosynthesis than those with a lower growth rate,and feeding activity was inhibited by long-chain fatty acid biosynthesis.These results elucidate the relationships between health,feeding behavior,and the gut microbiota of Chinese alligator hatchlings.Understanding the intrinsic factors of their health and feeding behavior can improve the health management of Chinese alligator hatchlings in captivity for conservation.展开更多
Background: Accurately assigning hatchlings to the eggs from which they hatched is a prerequisite to understanding how the composition and environment of eggs affect the growth and survival of nestlings. Correctly ass...Background: Accurately assigning hatchlings to the eggs from which they hatched is a prerequisite to understanding how the composition and environment of eggs affect the growth and survival of nestlings. Correctly assigning hatchlings to their eggs can be a challenging endeavor, however, because multiple eggs within the same clutch can hatch at essentially the same time. Egg and hatchling mass are highly correlated in most bird species, and thus assigning eggs to hatchlings using their relative mass(e.g., matching the heaviest hatchling to the heaviest candidate egg) could prove extremely useful.Methods: To assess its potential utility, I applied relative mass assignment(RMA) retrospectively to a dataset of 133 Common Grackle(Quiscalus quiscula) nests in which all egg-hatchling dyads were determined unequivocally.Results: I found that RMA correctly assigned approximately 90% of hatchlings to their eggs when 2-4 hatchlings were present between checks. The number of nests in which hatchlings could not be assigned to their egg, however, increased monotonically from 13 to 46 to 78% for nests containing 2, 3, and 4 hatchlings, respectively, due to the greater likelihood that the mass of hatchlings or their candidate eggs was identical.Conclusions: Although RMA correctly identified the vast majority of egg-hatchling dyads, researchers should use this method with caution, because it will always inflate positive egg-size effects and thus could potentially result in erroneously reporting significant effects.展开更多
Gekko japonicus is a multiple-clutched gecko,with females laying normally two and occasionally one rigid-shelled egg per clutch.No seasonal shifts in clutch mass and egg mass were found in this study,and both variable...Gekko japonicus is a multiple-clutched gecko,with females laying normally two and occasionally one rigid-shelled egg per clutch.No seasonal shifts in clutch mass and egg mass were found in this study,and both variables were positively correlated with maternal size (SVL).Eggs were incubated at five constant temperatures ranging from 24 to 32℃ to assess influence of incubation temperature on eggs and hatchlings.Incubation temperature significantly affected duration of incubation.The average duration of incubation at 24,26,28,30 and 32℃ was 81.4,62.5,52.6,44.7 and 39.5 d,respectively.Hatchlings from eggs incubated at 28℃ were slightly heavier in total dry mass than those from 24 and 26℃,and all other examined hatchling traits (SVL,TL,carcass,residual yolk,fat bodies,head size) did not differ among temperature treatments.Our data reveal that variation in incubation temperature over a wide range does not have important effects on body size and shape of G.japonicus hatchlings.展开更多
基金supported by the National Natural Science Foundation of China(Nos.32000355,32170525,32370561)Anhui Science and Technology Major Project(202003a06020028).
文摘Chinese alligator hatchlings in captivity are fragile and have a high mortality rate within first year.The body mass gain of reptile animals is closely related to their feeding behavior and gut microbiota.This study analyzed the intrinsic factors influencing the allometric growth of Chinese alligator hatchlings based on their body mass gain,feeding behavior,and gut microbiota.This information would enhance the health management of Chinese alligator hatchlings.There was a significant correlation between the total distance moved,the average number of conspecifics nearby,and body mass gain.Chinese alligator hatchlings with a greater growth rate showed greater activity and more independent behavior during feeding than those with a lower growth rate.Moreover,after feeding started,some functions of the gut microbiota showed significant relationships with growth rate and feeding activity.Chinese alligator hatchlings with a greater growth rate showed greater levels of heme biosynthesis than those with a lower growth rate,and feeding activity was inhibited by long-chain fatty acid biosynthesis.These results elucidate the relationships between health,feeding behavior,and the gut microbiota of Chinese alligator hatchlings.Understanding the intrinsic factors of their health and feeding behavior can improve the health management of Chinese alligator hatchlings in captivity for conservation.
基金Funding was provided by the University of Illinois,Program in Ecology,Evolution and Conservationthe American Ornithologists’Union Research Award.L.S.Johnson provided useful comments on an earlier version of the manuscriptsupported by an NSF International Fellowship OISE-1159178
文摘Background: Accurately assigning hatchlings to the eggs from which they hatched is a prerequisite to understanding how the composition and environment of eggs affect the growth and survival of nestlings. Correctly assigning hatchlings to their eggs can be a challenging endeavor, however, because multiple eggs within the same clutch can hatch at essentially the same time. Egg and hatchling mass are highly correlated in most bird species, and thus assigning eggs to hatchlings using their relative mass(e.g., matching the heaviest hatchling to the heaviest candidate egg) could prove extremely useful.Methods: To assess its potential utility, I applied relative mass assignment(RMA) retrospectively to a dataset of 133 Common Grackle(Quiscalus quiscula) nests in which all egg-hatchling dyads were determined unequivocally.Results: I found that RMA correctly assigned approximately 90% of hatchlings to their eggs when 2-4 hatchlings were present between checks. The number of nests in which hatchlings could not be assigned to their egg, however, increased monotonically from 13 to 46 to 78% for nests containing 2, 3, and 4 hatchlings, respectively, due to the greater likelihood that the mass of hatchlings or their candidate eggs was identical.Conclusions: Although RMA correctly identified the vast majority of egg-hatchling dyads, researchers should use this method with caution, because it will always inflate positive egg-size effects and thus could potentially result in erroneously reporting significant effects.
文摘Gekko japonicus is a multiple-clutched gecko,with females laying normally two and occasionally one rigid-shelled egg per clutch.No seasonal shifts in clutch mass and egg mass were found in this study,and both variables were positively correlated with maternal size (SVL).Eggs were incubated at five constant temperatures ranging from 24 to 32℃ to assess influence of incubation temperature on eggs and hatchlings.Incubation temperature significantly affected duration of incubation.The average duration of incubation at 24,26,28,30 and 32℃ was 81.4,62.5,52.6,44.7 and 39.5 d,respectively.Hatchlings from eggs incubated at 28℃ were slightly heavier in total dry mass than those from 24 and 26℃,and all other examined hatchling traits (SVL,TL,carcass,residual yolk,fat bodies,head size) did not differ among temperature treatments.Our data reveal that variation in incubation temperature over a wide range does not have important effects on body size and shape of G.japonicus hatchlings.
