Manducus

Abstract: Recent studies have suggested that the family Gonostomatidae is monophyletic if Diplophos, Manducus, and Triplophos are excluded, but no supportive characters for this hypothesis have been described. The remaining four genera, Bonapartia, Cyclothone, Gonostoma, and Margrethia, are found to share such derived features as loss of IP photophores, a shortened premaxilla, a peculiar pattern of maxillary dentition, and modified pharyngobranchials. The current analysis shows Cyclothone to be a clade nested within Gonostoma, rendering the latter paraphyletic. With these results Cyclothone should be considered a junior synonym of Gonostoma but the classification is not amended at this time, pending the completion of other studies. The relationships of this restricted Gonostomatidae to other stomiiform subgroups is discussed. Diplophos and Manducus are proposed to be sister groups and together comprise the sister group of all other stomiiforms. The evidence for the interrelationships of Triplophos is contradictory but initial data presented here indicate that this genus is probably more closely related to the photichthyans than to gonostomatans.