you could possibly do soemthing like this

buy a less expensive species of jaw fish
dont use safegaurd
see if anything happens to it

nice one...
would feel bad for this canary in the mine jawfish though....

Did not know that they came from the Sea of Cortez thats good to know.
well that should rule that out then.
I am pretty sure it was not Safeguard related as I added that on the first two days and he was fine for 8 days after including water changes, and carbon additions to remove it after. The first one was in the main tank and it has no problems or Safeguard so that rules out that pretty much.
Maybe they were towards the end of thier life I believe they only live for two years.
Oh and yes they really like to jump. I had to remove him from the back two times.
I think I will try a different one first. I picked up a yellow Coris yesterday so far he is doing well in the same tank so will see how this one makes out.