Plaice are tasty, not particularly fast and have about as much defensive body armour as a bowl of porridge. In evolutionary terms, this means that they needed to find a form of defence pretty quickly or find themselves facing extinction.
The strategy adopted, however, does seem a little drastic, with a complete bodily change taking plaice, sorry place, very soon after the fish has hatched.
Plaice are one of the sea angler's favourite fish. Whether it be from boat or shore there is something about seeing one of these tasty flatfish emerge from the depths that just quickens the pulse, which is why we have dedicated this part of the website to it, starting with a brief account of its fascinating lifestyle.
Starting life as a perfectly normal round fish, the young plaice soon begins an incredible metamorphosis that will completely transform both its body and its life. It hatches, if it is lucky, in the middle of a rich bloom of phytoplankton – tiny plant lifeforms that will keep it alive when it is very young– but then, shortly afterwards, it heads down towards the ocean floor, where it starts swimming on its side.
As if this was not a strange enough thing to do, the creature’s body then starts to flatten, with a startling transformation taking place. Its eyes begin to migrate over its head until they both come to rest on the same side and, while this is going on, its colouration also begins to change. The side that is facing the seabed turns white, becoming a blind side, while the top of the fish begins to turn a dusky brown that will blend in with its surroundings. Then, as the fish grows, so its colouration deepens to the point where the plaice is very well hidden indeed. It can even add to this protective camouflage by assuming spots of different colours, imitating the stones found in its immediate vicinity. The plaice over the Skerries, for example, are often found to have white spots that imitate the shingle over which they are caught.
Camouflage is a useful survival tactic, but it also has other effects on the lifestyles of the creatures that adopt it. In the case of the plaice, for example, its protective camouflage imposes strict limitations on its diet. Basically, if you have to keep your head down, then you are going to have to find your meals on the floor, in this case the ocean floor. Fortunately for the plaice this is a very rich source of food, with ragworm, lugworm, crabs, clams, other shellfish such as razorfish, sandeels and shrimps all readily available for whenever it is feeling peckish.
Its diet is also influenced by its size. At first the plaice has to content itself with smaller meals that its soft mouth and small stature can contend with, such as ragworm, shrimps, lugworm and comparatively fragile shellfish such as telchines. However as it grows so its skin toughens and its jaws become stronger, enabling it to deal with larger, more heavily armoured prey. At this point it begins to feed on the rest of the varied diet available in its chosen environment, pursuing sandeels with predatory gusto, crunching larger crabs and even tackling razorfish, the shells of which its digestive system can grind to powder and then expel as waste material.
Bear this in mind when you are fishing. It is no coincidence that larger plaice are caught on big baits like razorfish. They are used to them. When I fish, I use several ragworm pushed up the trace and then tip the hook with a long strip of sandeel, usually the greater sandeel which is known as launce. These are nice and bright and big enough to interest the really large plaice that I would dearly love to catch. I won’t stint on the bait either, making the strip at least six inches long while the ragworm make up another eight.
If you want to catch bigger fish, try something as simple as using bigger baits!