Revealing mistake: Right at the beginning of the film when the crew walk down the tunnel from the shuttle to the space station, one on the left of screen bumps into the massive metal airlock door. It wobbles.
Revealing mistake: When they land on Mars, pay attention to the 3 vents in the front of their helmets - at certain angles you can see there's no screens or obstructions - just 3 holes straight through and you can see their skin.
Chosen answer: They aren't given a name. They act like plants, except instead of absorbing carbon dioxide and expelling it as oxygen, they eat plants and release oxygen from their bodies. It's probably more effective than using plants since they weren't expecting to be able to breathe on the surface.
Knever