Today’s fish doesn’t have nearly as neat of a name as most of the fishes I pick, but I still maintain it’s a pretty interesting fish. Despite its name, the lemon sole is neither a lemon nor a sole. It doesn’t even taste like a lemon. It seems the name lemon sole probably originates from the french name ‘sole limande’, limande either coming from the french work ‘lime’, or file, or the word ‘limon’, meaning slit. Whatever the case, this fish is poorly named.
The lemon sole is a flatfish, which is an appropriate name, since flatfish tend to be flat. These fish are adapted to a life on the sea bottom, feeding on invertebrates on the sea floor. Fun fact: the first fish I ever caught was a flatfish, a flounder off the coast of British Columbia. It was delicious. The adaptations flatfish have developed to accomodate their lifestyle are what make the fish so funny looking. Here’s a picture of a lemon sole:
Flatfish differ in their method of being flat; some species (like the lemon sole) are right-sided – the right side of their body faces up and the left side to the sea floor. Others are completely left-sided, while other species have a mix of right- and left-sided fish. Still other flatfish simply are flat from top to bottom; and don’t pick one side or the other.
Interestingly, flatfish are not born like that. In fact, they are born like most fish, with eyes on both sides of their heads, swimming upright. They don’t turn into freaks until later. The lemon sole, at ten days old, looks like any other baby fish. Its body is symmetrical, and it has a has a large, upright skull. At thirteen days, however, the lemon sole begins to change. The skull starts to become compressed and flat, and the left eye starts to move. Yes, move. The left eye of the lemon sole migrates around the fish’s head, until it’s on the animal’s right side. Which is crazy, but makes sense; you wouldn’t want an eye looking down into the sand your whole life.
Many flatfish experience this kind of metamorphosis as they mature, though in some species, instead of moving around the skull, the bottom eye instead moves through it. Can you imagine? Having an eye go through your skull? No thanks. Apparently the lemon sole also thought this was gross, as it opted for the less invasive procedure. At 35 days, the eye finishes migrating and the sole’s upper side starts to develop a distinctive pattern; camouflage for the animal’s bottom dwelling life. This extensive metamorphosis is controlled by the same hormone that initiates transformations in tadpoles, the thyroid hormone.
Overall, this strange method of development seems like a lot of work for not much effort, but it does provide the fish with ample camouflage. And they seem to do okay. I’m just saying, it’s not the lifestyle for me. But then, I’m not a lemon sole. I do however, have a hankering to try one now…