Honestly the best place to find a Tuso is the western part of Ragnarok, at roughly 50,10. There is a medium sized trench that houses at least a dozen. Here's an easy way to tame.

1) Grab something to breathe underwater. (Scuba or a tek helmet)

2) Grab a beefed up tame with good hp. (I use a Shadowmane because they breathe underwater and have insane natural armor)

3) Let the Tuso Grab your tame and while it's latched, swim up and feed it one stack of 50 black pearls. It has to be 50. Any type of meat will take you 3 hours compared to a couple minutes.

4) Rinse and repeat. Be prepared to die, taming a Tuso for the first time isn't super easy but remember not to panic. Clear the area out around the Tuso you want to tame first and then try.

More Tusoteuthis Taming & KO Tips