Using X-ray video, scientists have discovered that baby Japanese eels slither backwards out of the stomachs of predatory dark sleeper fish after being swallowed, and slip away through the gill slits to freedom.

>Once swallowed into the digestive tract of the predator, A. japonica gradually reduced its activity and ceased all movements (i.e., death) within 211.9 seconds on average. There was a correlation between the duration of activity within the digestive tract and the weight of A. japonica (generalized linear mixed model: df = 1, χ2 = 5.21, p < 0.05). Additionally, there was a significant effect of the body weight of A. japonica on their escape probability (generalized linear mixed model: df = 1, χ2 = 4.26, p < 0.05). Therefore, it is probably essential for eels to develop muscle strength and locomotory performance to quickly escape from an anaerobic and highly acidic environment as well as tolerate such a lethal environment. Further experiments involving prey–predator interactions with various sizes of A. japonica, while measuring their locomotory performance and tolerance to severe environments, are necessary to identify the specific factors that enable successful escape.

That is supercool. The Japanese Eel is such a big animal. Babies, but still.

The image of the process of escaping that was included in the study, was very good. Here:

[https://www.cell.com/cms/10.1016/j.cub.2024.07.023/asset/e32686ca-7cbd-40bf-8c8a-f97b239939a2/main.assets/gr1.jpg](https://www.cell.com/cms/10.1016/j.cub.2024.07.023/asset/e32686ca-7cbd-40bf-8c8a-f97b239939a2/main.assets/gr1.jpg)