Fish Buffet: Dietary Observations in the Oman Saw-Scaled Viper (Echis omanensis), with a Review of Fish-Eating Vipers.

Diet is an important ecological variable that has contributed significantly to the evolution of snakes, yet the diets of many species are still poorly known. Here, we report for the first time observations of the arid-adapted Echis omanensis feeding on fish. On two occasions we observed adults of this species preying on Garra barreimiae in drying pools in the United Arab Emirates. In one case, a snake was seen ingesting a fish in Wadi Shawka, Ras Al Khaimah, and in another, an individual was observed actively searching for and capturing fish in Wadi Wurrayah, Fujairah. These records provide direct evidence that E. omanensis can opportunistically exploit fish as prey in ephemeral freshwater habitats. To place these observations in context, we reviewed primary and non-primary sources to identify 14 fish-eating species in the Viperidae family. This review alludes to fish as rare, seasonal or region-specific prey among vipers. More broadly, these findings underscore the value of natural history observations for documenting unusual prey in snakes.