I just use it as an imagination thing. Maybe it’s super spooky bacteria or maybe it’s home to mega T-Rex? You can decide!
I think complex life is extremely rare if it exists at all in the Persean Sector. Or space... In the Starsector's universe.
Volturn, Jangala have primitive native life. I think. There is no mention of actual animals at all. There is only that one gas giant in Valhalla if I recall correctly. But that's a conspiracy theory. Inimical biosphere funnily enough doesn't even necessarily imply alien life. The things that terrorise the landscape could be just mutated Terran-analogues left behind by the initial Domain terraforming projects.
The gas giant the life on Chalcedon descended from is also not described. And considering Domain took barely any interest in studying it, it mustn't have been that interesting.
The most complex life besides humanity I think are the hyperspace entities. Whatever they are.
That reminds me... I used to have nightmares about phase giants.