It looks like a barracuda to me.

It's a Barracuda.... In most cases, a barracuda is dark blue, dark green, white, or gray on its upper body, with silvery sides and a chalky-white belly. Coloration varies somewhat between species. For some species, irregular and unorganized black spots or a row of darker cross-bars occur on each side. Their fins may be yellowish or dusky. Barracudas live primarily in oceans, but certain species, such as the great barracuda, live in brackish water.