Plaice can live to be 50 but only if their spots don't give them away, says Paul Naylor
EATING ON THE MOVE Plaice are usually seen lyingstationary on sand or mud but they feed while cruising over the seabed, preying on molluscs such as cockles and other small animals - shrimps, brittle stars and worms. Clam siphons protruding from the mud are nipped off before they can be retracted, and are a favourite delicacy. Young plaice appear hardly to feed in winter, undergoing a sort of hibernation.
SEX LIFE BORING Female plaice lay up to half a million eggs at a time. Mating is not very intimate, with eggs and sperm simply being released into the water. It is not totally haphazard, however, because the female releases the buoyant eggs beneath the male, to maximise fertilisation as they float up through his cloud of sperm.
GOING WITH THE FLOW During their migration to spawning grounds, plaice can cover more than 15 miles in a day. Tagging experiments have found them moving from the Yorkshire coast to the English Channel in fewer than three weeks. They adopt the sensible strategy of swimming with the tide when it flows in the direction in which they want to go, and resting on the seabed while it flows against them.
FLATTER & TWISTED As flatfish, plaice have a very odd life-history. Newly hatched from the floating egg, tiny plaice look like conventional fish with the body positioned vertically in the water and an eye on each side. As they develop, still in open water, the body prepares itself for a life lying on its side and the plaice adopts the typically twisted facial expression of all flatfish.
A ROVING EYE By the time young plaice adopt the bottom-living life, their left eye has moved over to join the right eye on that side of the body. The right-hand side lies uppermost and is coloured accordingly. The eyeless left or 'down' side is white. Plaice are termed 'right-sided', in common with most flatfish. A few perverse species like the topknot lie with their left sides up.
CAMOUFLAGE TIPS NEEDED With their characteristic bright orange spots, plaice are the most easily recognisable flatfish in UK waters. The spots often give them away, as the rest of the body coloration is usually a perfect match for their habitat. Plaice can live for 50 years and grow to almost a metre in length but such large specimens are extremely rare.