star wars - How does the Space Slug (Exogorth) breathe in the vacuum of space?

Whilst answering this question, an interesting question came to mind.

In the chase through the Hoth asteroid field in The Empire Strikes Back, the Millennium Falcon takes refuge in a cave, which turns out to be the belly of a Space Slug (Wookieepedia tells me that this creature's proper name is an Exogorth).

I never really thought about it before, but how does this creature breathe? Wookieepedia mentions how it gains nourishment

They fed on the minerals of asteroids, various stellar energy fields, mynocks (another silicon-based lifeform), ships, and other unfortunate creatures that unknowingly passed into its mouth.

but school biology teaches me that all living things need to breathe.

Since Wookieepedia is normally pretty good at collating any ridiculous explanation that might have been given in any form of canon and I don't see anything specified, I fear there may be no answer, but I am still curious.

Answer

Presumably, they don't need to.

As your excerpt hints at, at the Wookieepedia clarifies, the Exogorth is a silicon-based life form.

All of your biology lessons will have been given based on knowledge of terrestrial, carbon-based life forms. Oxygen is used in our physiology as part of a complex process, which includes the need for a highly electronegative element.

If a similar process is needed in this silicon-based lifeform, then in all likelihood they use a different element or molecule that's found within the asteroids, and process it in such a way that:

1. Allows them to use it for their respiration-equivalent process (notice the anatomy picture in the wiki includes no lungs, so they breathe different than many Earth animals)


2. Allows them to store it for long periods of time, as the resource may be hard to find through their limited asteroid-hopping.

However, silicon is a fairly boring element, so far as we know, and doesn't form bonds like our organic chemistry does. In all likelihood, the physiological processes required to sustain such silicon life won't have direct parallels on the microscopic scale.