Mr. Hirst often aims to fry the mind (and misses more than he hits), but he does so by setting up direct, often visceral experiences, of which the shark remains the most outstanding.
In keeping with the piece's title, the shark is simultaneously life and death incarnate in a way you don't quite grasp until you see it, suspended and silent, in its tank. It gives the innately demonic urge to live a demonic, deathlike form.