Viper underwater...?

[Ruggero M.]

Thank you all for confirming my suspicions about these photos.

However, I think it's very unlikely that they feed underwater...even Natrix consume their prey on land.

It would be interesting to see/hear of more cases related to this!

I think Natrix species do consume occasionally their prey under water, and this footage can confirm my opinion: https://www.youtube.com/watch?v=p3ftqgYCA_k
I've seen N.tessellata in the wild lurking for small fishes in rather deep water, but I could not remember the actual capture of fishes: anyway it's probable, in my opinion, that they could have swallowed small preys even during diving.
This does not mean that our pictures are not fake ones: the postures of the snake are very suspicious, and the environment seems a small acquarium with white artificial gravel indeed...

[Ilian Velikov]

I'm willing to bet that every heathland in Europe can have summer temperatures above the physiological optimum of berus. This is not the most thermophilic species.

You're right. So thermoregulation makes sense here too.

Ruggero, thanks for this footage. Another interesting one. All Natrix I've seen (mostly tessellata) with prey went out of the water to consume it. Like the one below.
Maybe it's not a physiological problem for them but rather a matter of prey size = the bigger the prey the more likely it is to struggle free from the snake's grip hence if it's fish (like with tessellata) it's better to be out of water. It looks like it's not a problem to consume small prey that is firmly secured underwater.

So that makes me think - Is there any anatomical difference between Natrix and Vipera that would allow Natrix to consume prey underwater? At least I can't think of any...
So maybe it's not impossible for vipers to consume prey underwater (of course those photos are still fake, that's established).

[Niklas Ban]

Other speciem like cornsnakes, Pythons and also bitis rhinoceros have no problems to eat their prey under water, why Vipera should?
V. berus likes moores as habitat, so it would be very eficient for them to go under water to eat some frogs or tadpoles..