The Notacanthiformes comprise the families Halosauridae and Notacanthidae. Both families are found in deep waters on the continental slope, typically in depths greater than 500 m in Australian waters. Like their relatives, the true eels (Anguilliformes), halosaurs and spiny eels have a leptocephalus larval stage.
Forey et al. (1996) placed the Halosauridae and Notacanthidae in the order Notacanthiformes. Wang et al. (2003), who did not include any halosaurs in their phylogeny, recognised the Albulidae and Notacanthidae as belonging to the Albuliformes. Inoue et al. (2004) included the halosaur Aldrovandia in their study and defined the Albuliformes as comprising the Albulidae, Halosauridae and Notacanthidae. Nelson (1994, 2006) included the families Albulidae, Halosauridae and Notacanthidae in the order Albuliformes.
Wiley & Johnson (2010) define the order and follow Forey et al. (1996) in recognising the families Halosauridae and Notacanthidae in the Notacanthiformes. Kanehira et al. (2012) reassessed phylogenetic relationships based on osteological characters.
Forey, P.L., Littlewood, D.T.J., Ritchie, P. & Meyer, A. 1996. Interrelationships of elopomorph fishes. pp. 175-192 in Stiassny, M.L.J., Parenti, L.R. & Johnson, G.D. (eds). Interrelationships of Fishes. San Diego : Academic Press 496 pp.
Inoue, J.G., M. Miya, K. Tsukamoto & M. Nishida 2004. Mitogenomic evidence for the monophyly of elopomorph fishes (Teleostei) and the evolutionary origin of the leptocephalus larva. Molecular Phylogenetics and Evolution 32(1): 274-286.
Kanehira, N., Imamura, H. & Yabe, M. 2012. Phylogenetic relationships of the suborder Notacanthoidei (Teleostei: Albuliformes) reassessed from osteological characters, with a proposed new classification. Memoirs of the Faculty of Fisheries Sciences, Hokkaido University 54: 1–28. PDF Open access
Nelson, J.S. 1994. Fishes of the World. New York : John Wiley & Sons 600 pp.
Nelson, J.S. 2006. Fishes of the World. Hoboken, New Jersey : John Wiley & Sons, Inc. 601 p.
Smith, D.G. 1984. Elopiformes, Notacanthiformes and Anguilliformes: relationships. 94-102 figs 45-54 in Moser, H.G. et al. (eds). Ontogeny and Systematics of Fishes. American Society of Ichthyologists and Herpetologists. Special Publication 1: 1-760
Wang, C.H., Kuo, C.H., Mok, H.K. & Lee, S.C. 2003. Molecular phylogeny of elopomorph fishes inferred from mitochondrial 12S ribosomal RNA sequences. Zoologica Scripta 32(3): 231-241
Wiley, E.O. & D.G. Johnson. 2010. A teleost classification based on monophyletic groups. Pp. 123-182. In Nelson, J.S., H.-P. Schultze & M.V.H. Wilson (eds.) Origin and Phylogenetic Interrelationships of Teleosts. Verlag Dr. Friedrich Pfeil, München, Germany, 480 p.