BIOGEOGRAPHY OF GADOID FISHES

Fourteen families of gadoid fishes (cods and their allies) are recognized here, each of which is mapped globally. Summaries are given of the distribution of each family and their hypothesized phylogenetic relationships followed by regional accounts in which are recognized specific Atlantic, Caribbean and Indo-Pacific patterns. These patterns are discussed with respect to gadoid phylogeny. It is concluded that discontinuous bipolarity, which among gadoids is centred on the Atlantic, is the result of disruption of a formerly widespread distribution; the northern Pacific gadoids represent recent dispersals of derived taxa (supragadoids). Circumglobal distribution is present essentially in primitive taxa (infragadoids) and is interpreted as a plesiomorphic pattern. The vertical distribution of gadoids is also considered and, in contrast to other paracanthopterygians, the phylogenetic trends appear to have been from oceanic to shelf habitats.