I still don't have my shark fursona, but when I'll finally make it, I sure that anatomy and proportions of body are gonna be like this. Really, in my humble opinion, close-to-perfect anthro shark should be looking like this. Sexy humanoid body, a bit changed big shark head with the fin on the back, lips to make "speaking ability" believable, wide shoulders to handle this head and thin and curvy tail.

This time I definitely recommend to watch all renders in max resolution, to see all details: https://www.artstation.com/artwork/Qzg6YL

Rendered in Blender 2.8