There are four Types of general body shapes for most fishes:
Fusiform: Like Tuna Fishes, and most Sharks, this body shape has a larger, rounded on front, and almost pointy in the rear.
Attenuated: Like Eels allows it to wiggle into small crevices where it hunts prey, like a snake.
Depressed: (Flat ventrally) like the Angler fish and most Flat Fishes.
Compressed: (Flat Vertically) reef fishes such as the butter fish gives the fish great agility for movement around the reef and can support sudden bursts of acceleration.
The Triggerfish is flat from side-to-side, it's mostly on reefs and moves around with great agility; and the Hawkfish has a Torpedo-like body, round in front, pointy in the tail. The body shape then is compressed.