Plaice (Pleuronectes Platessa) may always be identified by their red spots. They are fairly plentiful all round our coasts, and in places afford really good sport to the sea angler. Like most other flat fish, they haunt sandbanks and muddy bottoms, and may often be found in quantities on sandy patches surrounded by rocks. I have caught them in three fathoms of water, or less.
A very perfect mare's nest was once discovered in connection with these fish. The theory was started that they were descended from shrimps, and a naturalist, to test the statement in a praiseworthy practical manner, obtained a few live shrimps and kept them in a tank. At the end of a few days he found in the tank some young plaice, and further investigations tended to show that the eggs of the plaice were sticking to the shrimps when placed in the little aquarium. In the following year he half filled two vessels with salt water, making one the home of a few plaice, devoting the other to plaice and shrimps. In both vessels the plaice spawned, but only in the vessel containing the shrimps did the ova hatch. So the experimenter came to the conclusion that in some way the shrimp was essential to the hatching of a plaice egg. Since that day, however, plaice eggs have been hatched in the laboratory of the Marine Biological Association at Plymouth and other places, and this without the assistance of shrimps.
Plaice are fished for on the bottom with such tackle as that shown on p. 243, and many more will be caught if a rod is used than on a hand line. I prefer a hook about half the size of those used by the fishermen, baited with lugworm, mussel, ragworm, peeled uncooked shrimp, cockle, or any soft bait I have caught not a few of these fish on pieces of sprat, mackerel, and squid. Now and again a plaice as large as seven pounds is captured, and fish of fifteen pounds weight are on record. From three-quarters of a pound to two and a half pounds is the more common size.