Snakes are famous for being able to get their jaws around just about anything, from eggs to birds and even centipedes. However, one snake in France bit off much more than it could chew, and that might be just the beginning of the story.

Two extraordinary images captured by herpetologist Nicolas Fuento show a viperine snake (Natrix maura) with a species of fish called a ruffe (Gymnocephalus cernua) wedged in its throat. The encounter happened at the Lac de Carcès in southeast France. 

While you might think the snake was just unlucky in choosing the wrong fish dinner, the reality is a little more complicated. Viperine snakes typically feed on small fish species. This ruffe is a species native to large parts of Europe and Asia, including France. However, it is invasive, spread by human-made canals or escaping from bait buckets used by anglers. The team believe that this was a failed predation attempt by the snake on an invasive species.

The snake attempted to expel the fish from its esophagus for several minutes until Fuento removed it. The fish had died, but the snake appeared to be fine and moved away into the undergrowth. The dorsal spines from the fish had lodged in the upper part of the wall of the esophagus.

The two co-authors wrote in the study, “Although in several cases snakes can survive injuries caused by fish spines, we cannot confirm that in this case the snake would have survived without our aid.”

The researchers suggest that instances of fish-eating snakes preying on invasive fish species are becoming more widespread, and it's known that they can result in the death of the snake. Fish-eating species being killed by their prey accounts for 26 percent of snake mortality, but invasive species present a newer, real threat to the survival of native fish-eating snake species. 

The study is published in Herpetology Notes.