Could organisms live in the rings in a planet?

Think of Saturn.

In this book, some people travel to a gas giant with rings and find an ecosystem in the rings of a planet. It has predators and prey. It has plants and animals. Autotrophs and Heterotrophs. Here are details of the organisms living here.

Plants

-they are Autotrophs

-They absorb nutrients slowly from nearby rocks by roots. They anchor themselves to multiple rocks by a strong root system, they break occasiqnly.

-They reproduce by extending roots to other rocks too. Like a quaking aspen.

-They get energy from the nearby star.

-They are adapted to low gravity, no atmosphere, low nutrients (high nutrient, including oxygen, in rocks).

Animals

-They Are Heterotrophs

-They are adapted to low gravity, low nutrients, and no atmosphere.

-They get all energy from plants and other animals.

-They are adapted to jump to rock to rock.

-Extremly strong exoskeleton to withstand the vacuum of space.

-They communicate by vibrations through rocks, thus being on same rock to communicate.

-Reproduce by laying eggs under rocks in asteroids.

-They go around in packs.

-Packs attack other packs.

Question

Now my question is with all their adaptations, could they even exist?