Do fish/whales burp?

Question

Since I read here on Yahoo Answers that some fish actually drink water I have been haunted by this question. Do they burp?

Answer 1

Burping is a reflex reaction of the food pipe (oesophagus) and occurs only if 1 of 2 instances are satisfied:
1. When the food pipe is overloaded with excess food (that is why it is good to bite what you can chew and swallow only what your food pipe can take).
2. When excess acidity forms and gases needs to be released (the gases from the stomach are expelled via food pipe) which comes out as a burp.

This is also true for fishes and whales, as they also have the food pipe (connecting their mouth and stomach/crop). When excessive acidity is formed, they have to burp. However, the burping will be too subtle to be noticed blatantly.

Answer 2

Fish don't burp because they don't actually take oxygen into their stomachs, which you need in order to burp. The oxygen they breathe is filtered through their gills instead, so it never has the opportunity to go elsewhere.

As for whales, they inhale through their blowholes, which aren't connected to their stomachs. I suppose it is possible for whales to swallow air through their mouths when they surface, but I don't think that it would result in burping. They would probably pass gas instead.