Finding the Stoplight Loosejaw in the Stellar Basin took me so long that I thought I should save other people some time.
Stoplight Loosejaw for Stellar Basin’s researcher quest
Idk why they introduce the kraken suppression device and imply it is needed for finding the Loosejaw. I couldn’t find the Loosejaw inside the basin at all and it took me forever to find it because the two spawns I could find were on the outer perimeter.
Of the two locations, the first is easier: Facing the Old Fortress:


The second is to the southeast of the basin:


I don’t even know if spawns are randomized or predefined. Hopefully the latter so I didn’t just waste 5 minutes.
Thanks to QuasimodosLump for his excellent guide, all credits belong to his effort. if this guide helps you, please support and rate it via Steam Community. enjoy the game.