Galley et al. (2006) sampled cod aged 2 to 4 years old on known spawning grounds in the Irish Sea, the Firth of Clyde, the South Minch, Papa Bank, Shetland, Viking Bank and the Moray Firth and analysed differences in general shape descriptors (e.g. rectangularity, circularity etcetera) and harmonics produced by Carte...