This order contains nine families of small to medium-sized, soft-bodied fishes (Cohen et al. 1990; Nelson 2006). Most are deepsea fishes found below 200 m and many are important commercially. Relationships are treated in Cohen (1989), Howes (1991) and Endo (2002). The classification of this group is in dispute and Nelson (2006) has summarised the various arguments.
Cohen, D.M., Inada, T., Iwamoto, T. & Scialabba, N. 1990. FAO Species Catalogue. Gadiform fishes of the world (order Gadiformes). An annotated and illustrated catalogue of cods, hakes, grenadiers and other gadiform fishes known to date. FAO Fisheries Synopsis No. 125. Rome : FAO Vol. 10 442 pp.
Cohen, D.M. (ed.) 1989. Papers on the systematics of gadiform fishes. Science Series. Natural History Museum of Los Angeles County 32: 1-262
Endo, H. 2002. Phylogeny of the order Gadiformes (Teleostei: Paracanthopterygii). Memoirs of the Graduate School of Fisheries Sciences, Hokkaido University 49(2): 75-149
Howes, G.J. 1991. Anatomy, phylogeny and taxonomy of the gadoid fish genus Macruronus Günther, 1873, with a revised hypothesis of gadoid phylogeny. Bulletin of the British Museum (Natural History) Zoology 57(1): 77-110
Nelson, J.S. 2006. Fishes of the World. Hoboken, New Jersey : John Wiley & Sons, Inc. 601 pp.