I am using Blender 2.83 as a part of my Masters project. I have obtained 3D models of various fishes (.obj files), and I import them using
File > Import > Wavefront (.obj)
The models loads without errors, but the textures are "corrupted". I would appreciate any help and/or pointers on how to fix this. You can see images below. The "dark spots" are transparent spots
Some (maybe all) of the models are obtained from sketchfab, which have 3D previews where the textures look correct. The fish "groups" are the models viewed from left and right.
Beneath you can see a closer look of a model as well as the UV-editor view in case that is relevant.