My guess - HRP/mayan/BP shortbody. It doesn't look bloated, it looks like a typical shortbody that's a bit fat. Is it pooping white stringy popp or anything?
Explanation for the tail - Fish have regeneration sections in the fins and tail that tell it what cells need to grow back after an injury or illness to that part. If a fish is injured below the section it has nothing to tell it to grow back those cells anymore and grow will stop with what the previous section tells it. Basically if a fish bites off the tip of the tail is will grow back fine, if a fish bites off a section down to the middle it won't have the 'code' to grow back anymore and it will leave a gap in the tail - which is how this tails appears in the pics you posted at least. I would not say it's genetic at this point.