Mitamura Hiromichi, Mitsunaga Yasushi, Arai Nobuaki, Yamagishi Yukiko, Khachaphichat Metha, Viputhanumas Thavee
Graduate School of Informatics, Kyoto University, Kyoto, Japan.
Zoolog Sci. 2007 Jul;24(7):643-7. doi: 10.2108/zsj.24.643.
The vertical movements of one Mekong giant catfish Pangasianodon gigas were monitored for 3 days in August 2004 using a depth-temperature micro data logger. The logger was recovered using an innovative time-scheduled release system and located by searching for VHF radio signals. The logger was found approximately 2.2 km away from the release point and provided (n=705,128) depth and temperature data collected over a period of 98 hours following the release. The fish spent more than 99% of its time at less than 3 m below the surface. The maximum swimming depth was 5.6 m. No sharp thermocline was present during the experiment. Temperature did not have any detectable effect on the pattern of vertical movement of the fish. The dissolved oxygen concentration (DO) was stratified, with a concentration of >60% saturation in the first 3 m below the surface falling to 10% saturation at depths lower than 4 m. This specific DO stratification was found to limit the vertical movement of the catfish.
2004年8月，使用深度温度微型数据记录器对一条湄公河巨鲶进行了为期3天的垂直运动监测。该记录器通过创新的定时释放系统回收，并通过搜索甚高频无线电信号进行定位。记录器在距离释放点约2.2公里处被找到，并提供了（n=705,128）释放后98小时内收集的深度和温度数据。这条鱼在水面以下不到3米的深度度过了超过99%的时间。最大游动深度为5.6米。实验期间没有明显的温跃层。温度对鱼的垂直运动模式没有任何可检测到的影响。溶解氧浓度（DO）呈分层状态，水面以下前3米处的浓度>60%饱和度，在深度低于4米处降至10%饱和度。发现这种特定的溶解氧分层限制了鲶鱼的垂直运动。
