Department of Hydrobiology and Protection of Ecosystems, University of Life Sciences in Lublin, Dobrzańskiego 37, 20-262, Lublin, Poland.
Department of Hydrobiology and Protection of Ecosystems, University of Life Sciences in Lublin, Dobrzańskiego 37, 20-262, Lublin, Poland.
Sci Total Environ. 2019 Dec 10;695:133913. doi: 10.1016/j.scitotenv.2019.133913. Epub 2019 Aug 14.
The majority of reports on the toxic effect of cyanobacterial metabolites on the freshwater invertebrates is based on determination of two endpoints: mortality or immobilization. However, detection of sub-lethal effects requires more sensitive indicators The aim of the present study was to evaluate the applicability of digital-video analysis for determination of early behavioral and physiological responses in the assessment of effects caused by the cyanobacterial neurotoxin, anatoxin-a (ANTX) at a broad range of its concentration (0.5-50 μg/mL). Swimming speed (SS), heart rate (HR), oxygen consumption (OC), thoracic limb activity (TLA) and abdominal claw movement (ACM) of Daphnia magna were evaluated. Swimming speed and abdominal claw movements were determined by digital analysis of video clips by Tracker® software; OC by Oxygraph Plus System® while HR, TLA and ACM by digital frame-by-frame analysis of video clips of microscopic view with the use of a media player software. The experimental study showed a concentration- and time-dependent decrease of SS, HR, OC, TLA and ACM. SS was inhibited as early as after 10 s of the exposure of Daphnia magna to ANTX, and the other physiological responses after 2 h. Further inhibition of these parameters was also noted after 24 h of the exposure. On the other hand, stimulation of ACM was noted at the lower (0.5 and 2.5 μg/mL) ANTX concentrations after both 2 h and 24 h of exposure. The results indicated that some behavioral and physiological biomarkers measured by video analysis may be a valuable tool for an early determination of toxic effects induced by cyanobacterial metabolites in zooplankters.
死亡率或固定率。然而，亚致死效应的检测需要更敏感的指标。本研究的目的是评估数字视频分析在评估蓝藻神经毒素anatoxin-a（ANTX）在广泛浓度范围内（0.5-50μg/mL）引起的效应时，对早期行为和生理反应的适用性。评估了大型溞的游泳速度（SS）、心率（HR）、耗氧量（OC）、胸肢活动（TLA）和腹部爪运动（ACM）。游泳速度和腹部爪运动通过 Tracker®软件对视频片段的数字分析来确定；OC 通过 Oxygraph Plus System®确定，而 HR、TLA 和 ACM 通过使用媒体播放器软件对微观视频片段的数字逐帧分析来确定。实验研究表明，SS、HR、OC、TLA 和 ACM 的浓度和时间依赖性下降。大型溞暴露于 ANTX 10 秒后 SS 就被抑制，而其他生理反应则在 2 小时后发生。暴露 24 小时后，这些参数的进一步抑制也被注意到。另一方面，在暴露 2 小时和 24 小时后，较低浓度（0.5 和 2.5μg/mL）的 ANTX 会刺激 ACM。结果表明，通过视频分析测量的一些行为和生理生物标志物可能是早期确定蓝藻代谢物对浮游动物毒性作用的有价值工具。
