In nature, Apostichopus japonicus exhibits a behavioral characteristic of emerging at night and sheltering during the day. Hence, it was commonly believed that longer and darker light conditions are better for a popul...In nature, Apostichopus japonicus exhibits a behavioral characteristic of emerging at night and sheltering during the day. Hence, it was commonly believed that longer and darker light conditions are better for a population of A. japonicus. In aquaculture situations therefore, animals have commonly been cultured without lighting, especially during juvenile-hatching culture. However, how the length of darkness each day affects .4.japonicus and what the mechanism is of behavioral response of A. japonicus to different photoperiods remain unclear, and are specifically addressed in this study. We applied nine photoperiod treatments （light：dark （LD） cycles at 0：24, 3：21, 6：18, 9：15, 12：12, 15：9, 18：6, 21：3, and 24：0 under 500Ix） to 60 individuals （29.73±0.23 g） per treatment （with 3 replicates）. The enviroramental conditions were set as： water temperature = 16.9±0.3℃, dissolved oxygen〉6.0 rag/L, ammonia〈0.3 mg/L, pH=7.8-8.2, and salinity=30-32. Under experimental conditions of continuous darkness as well as continuous light, cyclic nocturnal activity patterns of A. japonicus （viz. the animals emerged and fed at night and sheltered during the day） were observed. However, they spent more and less time, respectively, moving and feeding under continuous darkness and continuous light, than those under a natural light cycle. Under photoperiods with 6-12 h of light, the animals showed one sheltering behavior transition and two emerging behavior transitions. These behavior transitions appeared to be governed by some internal physiological factors and induced by daily light variation. The behavior of the animals was significantly affected by different photoperiods, and the distribution rate （DR） of the animals emerging at ＂daytime＂ increased with lengthening ＂light time＂ （except for the LD 3：21 cycle）. We also found that there was no significant difference in mean DR per day under LD cycles of 6：18, 9：15, 15：9, and 12：12. Mean DRs per day were significan展开更多
Distance traveled and home range size describe how animals move in space.The seasonal variations of these parameters are important to comprehensively understand animal ecology and its connection with reproductive beha...Distance traveled and home range size describe how animals move in space.The seasonal variations of these parameters are important to comprehensively understand animal ecology and its connection with reproductive behavior and energy costs.Researchers usually estimate the distance traveled as the sum of the straight-line displacements between sampled positions,but this approach is sensitive to the sampling frequency and does not account for the tortuosity of the animal’s movements.By means of the continuous-time movement modeling which takes into account autocorrelation and tortuosity of movement data,we estimated the distance traveled and monthly home range size of 28 wild boar Sus scrofa and modeled their inter-sexual seasonal variability.Males traveled longer distances and used larger home ranges than females,particularly during the rut in autumn-winter,consistently with the different biological cycles of males and females.Males enlarged their home ranges during the rut but traveled constant average distances along the year,whereas females traveled shorter distances in correspondence with the peak of food resources and birth periods but exhibited constant home range size across seasons.The differences between the seasonal variation patterns of distance traveled and home range size,observed in both sexes,revealed the complex relationship between these two aspects of spatial behavior and the great opportunity of including both distance traveled and home range size in behavioral ecology investigations.We provided a detailed analysis of wild boar spatial behavior and its relationships with the reproductive cycles of males and females,promoting a deeper comprehension of their behavioral ecology.展开更多
基金Supported by the National Natural Science Foundation of China (Nos. 30871931, 30771661)the National Key Technology Research and Development Program of China (Nos. 2006BAD09A01)the National Special Research Fund for Non-Profit Sector (No. 200905020)
文摘In nature, Apostichopus japonicus exhibits a behavioral characteristic of emerging at night and sheltering during the day. Hence, it was commonly believed that longer and darker light conditions are better for a population of A. japonicus. In aquaculture situations therefore, animals have commonly been cultured without lighting, especially during juvenile-hatching culture. However, how the length of darkness each day affects .4.japonicus and what the mechanism is of behavioral response of A. japonicus to different photoperiods remain unclear, and are specifically addressed in this study. We applied nine photoperiod treatments （light：dark （LD） cycles at 0：24, 3：21, 6：18, 9：15, 12：12, 15：9, 18：6, 21：3, and 24：0 under 500Ix） to 60 individuals （29.73±0.23 g） per treatment （with 3 replicates）. The enviroramental conditions were set as： water temperature = 16.9±0.3℃, dissolved oxygen〉6.0 rag/L, ammonia〈0.3 mg/L, pH=7.8-8.2, and salinity=30-32. Under experimental conditions of continuous darkness as well as continuous light, cyclic nocturnal activity patterns of A. japonicus （viz. the animals emerged and fed at night and sheltered during the day） were observed. However, they spent more and less time, respectively, moving and feeding under continuous darkness and continuous light, than those under a natural light cycle. Under photoperiods with 6-12 h of light, the animals showed one sheltering behavior transition and two emerging behavior transitions. These behavior transitions appeared to be governed by some internal physiological factors and induced by daily light variation. The behavior of the animals was significantly affected by different photoperiods, and the distribution rate （DR） of the animals emerging at ＂daytime＂ increased with lengthening ＂light time＂ （except for the LD 3：21 cycle）. We also found that there was no significant difference in mean DR per day under LD cycles of 6：18, 9：15, 15：9, and 12：12. Mean DRs per day were significan
文摘Distance traveled and home range size describe how animals move in space.The seasonal variations of these parameters are important to comprehensively understand animal ecology and its connection with reproductive behavior and energy costs.Researchers usually estimate the distance traveled as the sum of the straight-line displacements between sampled positions,but this approach is sensitive to the sampling frequency and does not account for the tortuosity of the animal’s movements.By means of the continuous-time movement modeling which takes into account autocorrelation and tortuosity of movement data,we estimated the distance traveled and monthly home range size of 28 wild boar Sus scrofa and modeled their inter-sexual seasonal variability.Males traveled longer distances and used larger home ranges than females,particularly during the rut in autumn-winter,consistently with the different biological cycles of males and females.Males enlarged their home ranges during the rut but traveled constant average distances along the year,whereas females traveled shorter distances in correspondence with the peak of food resources and birth periods but exhibited constant home range size across seasons.The differences between the seasonal variation patterns of distance traveled and home range size,observed in both sexes,revealed the complex relationship between these two aspects of spatial behavior and the great opportunity of including both distance traveled and home range size in behavioral ecology investigations.We provided a detailed analysis of wild boar spatial behavior and its relationships with the reproductive cycles of males and females,promoting a deeper comprehension of their behavioral ecology.
