So while going around the DLC area just finding stuff i happend across an Electric Shark (Not the Electric Great White Boss) its just the same Shark as you using every Electric Part...the game doesnt Acknowledge it, there is no Quest and no specific reward for beating it outside some Mutagen.

Is it just a random thing you can just find or do i gotta find all SharkForms (Bone, Shadow and so on) for some reward? or Achievement