Pilchard

Sardine and pilchard are common names for various species of small, oily forage fish in the herring family Clupeidae. The term 'sardine' was first used in English during the early 15th century; a somewhat dubious etymology says it comes from the Italian island of Sardinia, around which sardines were once supposedly abundant. The terms 'sardine' and 'pilchard' are not precise, and what is meant depends on the region. The United Kingdom's Sea Fish Industry Authority, for example, classifies sardines as young pilchards. One criterion suggests fish shorter in length than 15 cm are sardines, and larger fish are pilchards.

Source: Wikipedia