My best advice for dealing with the x fish is 'Run'! Went in the hard water cave with a lvl 265 baslo and a MC saddle and 7 of these guys destroyed it in less than a minute. The baslo I was riding had 60K health too.
You know I call these guys big ugly fish because that's what they are, big and ugly, and I have this vendetta because they took me off my mount in the water and mauled me apart while I had valuable items to take home
