Dark sleeper

The dark sleeper, Odontobutis obscura, is a species of freshwater sleeper native to Japan and Korea. This species can reach up to in length. It is a commercially important species. This species is also called toadfish.

Diet

The dark sleeper diet mainly consists of zoobenthos: chironomids, small aquatic bugs and larvae, which are all found in the benthic zone of the water column. In experiments, they will also predate on Japanese eels, with most afflicted eels even attempting to escape out of the digestive system into the esophagus and gills. Some eels succeeded in exiting through the gills. Eels that were completely inside the stomach constantly circled in it, as if searching for an exit.