Higher and lower-level relationships of the deep-sea fish order Alepocephaliformes (Teleostei: Otocephala) inferred from whole mitogenome sequences

Results from the present study support Alepocephaliformes as a genetically distinct otocephalan order as sister clade to Ostariophysi (mostly freshwater fishes comprising Gonorynchiformes, Cypriniformes, Characiformes, Siluriformes and Gymnotiformes). The disputed family Bathylaconidae was found to be an artificial assemblage of the two genera Bathylaco and Herwigia, with the former as the sister group of the family Alepocephalidae and the latter nested within Alepocephalidae. Platytroctidae was found to be monophyletic as sister clade to the rest of Alepocephaliformes. Previously unrecognized clades within the family Alepocephalidae are presented and a clade comprising Alepocephalus, Conocara and Leptoderma was recovered as the most derived. As long as the current classification is being followed, the genera Alepocephalus, Bathytroctes, Conocara and Narcetes were all found non-monophyletic. (C) 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 923-936.