Research on co-evolutionary behavior between large meso-pelagic squids and sperm whale

对于中远洋大乌贼，我们研制了专门的水下摄像机和照明系统，在不干扰深海环境的情况下，观察它们的自然行为。2011年，我们与NHK合作，首次在小笠原群岛的潜水器上成功观察并记录了巨型乌贼的活体。另一方面，我们开发了多记录仪系统和非常紧凑的水下摄像机，并多次将记录仪和摄像机安装在抹香鲸身上。记录器和相机图像为我们提供了详细的三维潜水痕迹，由此推断出抹香鲸对猎物鱿鱼的外壳和狩猎行为。此外，我们还观察了底栖清道夫的聚集过程，澄清了底栖清道夫群落的化学引诱物和时间演替。

Concerning to the mesopelagic large squids, we developed special underwater video camera and lighting system and utilized to observe their natural behavior without disturbing deep-sea environment. In 2011, we successfully observed and recorded live giant squid from submersible off Ogasawara Islands with cooperation of NHK for the first time. On the other hand, we developed multi-logger system and extraordinarily compact underwater camera and attached the logger and camera several times to sperm whales. The logger and camera images gave us a detailed diving trace in 3 dimensions by which casing and hunting behaviour of sperm whales to the prey squid were deduced. In addition, we observed a process of gathering benthic scavengers and clarified chemical attractant and temporal succession of benthic scavenger communities.