If You Had A Twin, But Didn't Realise...
Family Life7 mins ago
No best answer has yet been selected by coonsknob9. Once a best answer has been selected, it will be shown here.
For more on marking an answer as the "Best Answer", please visit our FAQ.My guess is probably not as we land-bound creatures tend to yawn as an act of ridding our bodies of excessive carbon dioxide. The common thought is that as grow tired or bored, we draw less oxygen into our bloodstream by not breathing so deeply. As we conversely exhale less, so CO2 builds up which will eventually be poisonous so the body responds by forcabily causing a large intake of air through the largest opening (i.e in most people, the mouth).
Fish breathe through their gills so keep watching them and see if they get bigger occasionally and then we'll know!!
hth
M