Shad, a common name, with or without an epithet, for several fish of the Herring family, generally ranked with the Herring, but sometimes made a separate genus. They are marine fish, ascending rivers to spawn, depositing their eggs on the bottom. In form and general appearance they resemble Herrings, but are of larger size. Their flesh is valued for food. The Common or Allice Shad (C. alosa) is common on the British coasts and in the estuaries of some of the larger rivers. The Twaite Shad (C. finta) is abundant round our coasts, and is found in the Thames. The American Shad (C. sapidissima), with an average weight of 4 or 5 lbs., is a valuable food-fish.