Well, after a tragic accident while on vacation, I had an empty tank to fill. I went out today to my favorite pet store and picked out a beautiful marbled white-and-blue doubletail. Upon getting him home, I noticed the end of his spine was crooked. A few google searches later I learn this is a common deformity from two doubletail parents, but couldn't find anything about the quality of life for fish who have this problem.
The DT I got is currently swimming without issue, appears very healthy, and has had no trouble going after food. He does not swim with that nice flowing stride like my other bettas however, his movements are quick and almost 'twitchy.' (Which could also be an age or personality thing.)
Can a fish live a full, fulling life with a crooked spine? Is he in any pain? Do I need to expect a shorter lifespan from this fish compared to others?