Not really an answer here but something I think is worth mentioning:
TLDR: If we could figure out how to capture, ride, tame, and breed horses: why couldn't we do the same with a biological organism that has a natural ability to survive and travel through space?
I think it may totally be possible given the following conditions that parallel events that have already happened on Earth. For this example, we will treat this biological ship as a space-faring counterpart to a terrestrial horse.
(P.S., I would love for anyone reading this who has more complete knowledge in early civilization to correct some of the assumptions I am making here)
In the future, we discover a biological organism, native to open space, which can survive and travel on its own devices. We will call this organism species-x.
How long did it take for humans to figure out how to ride a horse? Did it end there? No, we learned to domesticate and make them stronger through selective breeding. The same could be done with species-x.
There are different types of horses out there. Each with their own different "uses". Some horses are fast sprinters, some are more suited for long distance travel, some handle heat/cold better than others. The same could be said of species-x: The fast ones are bred for short interplanetary travel; some sub-set of species which are more efficient at storing/generating resources may be slower, but more well suited for interstellar travel.
Later, we learned to use the saddle. A technological tool that enhances not the horse itself, but our ability to ride and control the horse. This is a perfect analogy for technology that could be used to control this organism. Sensors that could be attached (or just monitor) the optic nerves of the organism could interpret the signals that are passing through and let the space traveler see what the organism sees. It could work the other way, in which we are allowed to mount sensors/functions/controls on the creature which is then tied in directly to the nervous system giving it extra "senses".