Normandie Univ, UNICAEN, Univ Rennes, CNRS, Caen, France.
Institute of Systems Neuroscience & Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan.
Dev Psychobiol. 2019 Nov;61(7):1014-1021. doi: 10.1002/dev.21868. Epub 2019 Jun 6.
Embryos perceive environmental stimuli, thanks to their almost mature sensory systems. In cuttlefish, the embryonic development of Sepia officinalis and Sepia pharaonis is similar but the egg capsule transparency is different. S. officinalis' eggs are black (ink), which provide protection from predators. Conversely, those of S. pharaonis are translucent. The aim of this study was to test the visual and chemosensory perception abilities of these two cuttlefish embryos by observation of the ventilation rate (VR) before and after stimulation. Our results show that S. pharaonis responds to light at stage 22 and S. officinalis at stage 24. Conversely, S. pharaonis responds to predator odor at stage 23 and S. officinalis at stage 22. Both species are able to respond to these stimuli before hatching but do not have the same developmental schedule. Neither are the responses of the two cuttlefish exactly the same. In S. officinalis, VR increases after stimulations. In S. pharaonis, VR increases after light stimulation and decreases following the odor stimulation after stage 25. This result could reveal an ability to recognize stimuli at stage 25. The decrease could be identified as freezing-like behavior which would be more adaptive than an increase, since the embryos are visible.
胚胎通过其几乎成熟的感觉系统来感知环境刺激。在乌贼中，鱿鱼和墨鱼的胚胎发育相似，但卵囊的透明度不同。鱿鱼的卵是黑色的（墨汁），可以提供保护免受捕食者的侵害。相比之下，墨鱼的卵是半透明的。本研究旨在通过观察刺激前后的通气率（VR）来测试这两种乌贼胚胎的视觉和化学感觉感知能力。我们的结果表明，墨鱼在第 22 阶段对光有反应，鱿鱼在第 24 阶段有反应。相反，墨鱼在第 23 阶段对捕食者的气味有反应，鱿鱼在第 22 阶段有反应。这两个物种在孵化前都能够对这些刺激做出反应，但发育时间表不同。这两种乌贼的反应也不完全相同。在鱿鱼中，刺激后 VR 增加。在墨鱼中，刺激后 VR 增加，第 25 阶段后气味刺激后 VR 减少。这一结果可能揭示了在第 25 阶段识别刺激的能力。减少可能被识别为类似于冻结的行为，这比增加更具适应性，因为胚胎是可见的。
