There is no fish species "red herring", rather it is a name given to a particularly strong kipper, made with fish (typically herring) that has been strongly cured in brine or heavily smoked. This process makes the fish particularly pungent smelling and, with strong enough brine, turns its flesh reddish. In this literal sense, as a strongly cured kipper, the term can be dated to the mid-13th century, in the poem "The Treatise" by Walter of Bibbesworth: "He eteþ no ffyssh But heryng red."