Low to medium poly Silvertip Reef Shark rigged. Game ready, originally designed to be used in Unity. This is one of my first animals I did a while back.
I appreciate the detailed feedback, thank you. This is one of the first critters I did a few years back, didn't even realize or remember I forgot to apply clipping to the mirror modifier.
[I gave your blend a thumbs-up, what follows is meant to be helpful. Feel free to ignore it.]
I've modelled and rigged a shark or two, so I thought I'd give yours a look.
Nice model, looks like some texture issues (I'd have to check references) - no big deal.
If you don't have MeshLint installed, do a search for meshlint.py and install it.
There are a couple of Tris at the tip of the lower jaw, don't think these can be fixed.
Lots of non-manifold verts (Claspers? 2/3 along bottom edge) which can be a problem when weight-painting.
[I'd guess you didn't enable 'Clipping' on your mirror modifier at the start.]
You don't need to apply Modifiers to export an FBX to Unity, so I wouldn't apply them.
Then there are some options for the SubSurf level.
I would apply the Mirror mod however, a finished model should have some assymetry.
Anyhow, thanks for sharing and feel free to take these comments for whatever they are worth.