As divers, we are in the unique position to witness the amazing diversity of life that inhabits the oceans. But on any given dive we are often surrounded by life that we don't recognize, or fail to see. Many marine creatures look far different as larvae and undergo several mutations before attaining their more recognizable adult form.

When it comes to appearance there is one fish we are all familiar with that goes against the rules and starts out looking pretty normal before undergoing a metamorphosis that seems more suited to a sci-fi horror flick.

When they hatch, flatfish look like most other larval fishes, less than an inch long and nearly transparent. And, like all other fish, they have one eye on each side of their head. Then, after a specific period of time, different for every species but usually within a few weeks of hatching, they undergo a major structural reorganization of bones, muscles and nerves. The bones of the skull begin to twist and become reshaped. One eye starts to migrate through their head or, in some cases, over the top of it, and takes up residence alongside the other. The body shape deepens and the small fish gradually swims increasingly more lopsided through the water. Eventually the small flatfish settles on its side on the bottom with both eyes now on the same side of its head staring upwards from what has now become its dorsal surface, the blind side of the flatfish becoming its ventral surface.

The flatfish is one of the most common sea creatures divers encounter along the Atlantic and Pacific coasts of Canada. To most of us they may all look very similarif we notice them at all. They spend most of their lives buried up to their eyeballs in the sand or mud bottom and the only time we might take notice is when they are disturbed and erupt from the bottom in a cloud of dust, swimming off with a great burst of speed using an undulating wave motion of their entire body.

For more on flatfish, pick up a copy of the March issue of DIVER Magazine.