ABSTRACT
Seven families, 12 genera and 19 species comprise the order Lampridiformes (Nelson 1994). Except for the velifers (family Veliferidae) that reside in shallow, coastal seas, all lampridiformes are oceanic, usually found in epi-, meso-and bathypelagic habitats. Most species are widely distributed in all oceans except polar seas. Adults of the deep-bodied species (lampridids and veliferids) possess symmetrical caudal fins and strongly developed skeletons and have been termed the bathysomous lampridiformes (Oelschlager 1983). Adults of the other five families (stylephorids, radiicephalids, lophotids, trachipterids, and regalecids) are more elongate with asymmetrical caudal fins and weakly developed skeletons. These species are historically termed the taeniosomes. Together, the lampridiform species constitute a monophyletic group of highly evolved and colorful oceanic fishes that are rarely seen and poorly represented in systematic collections (Olney et al. 1993, Wiley et al. 1998). The oarfish, Regalecus glesne, is the longest bony fish, reported to attain 17 m in total length and possessing crimson fins and a silver body (Olney 1998). Its tendency to be observed in surface waters after the passage of storms may be responsible for historical accounts by ancient mariners of sea monsters. Observations of living lampridiforms suggest that elongate species such as the oarfish and trachipterids normally orient in a vertical, head-up position and move vertically in the water column by undulating their long fin bases. Veliferids and lampridids swim horizontally in a typical teleostean posture. Lampridids are powerful swimmers, using large pectoral fins for forward propulsion (Rosenblatt and Johnson 1976). Several names have been used for this order including Allotriognathi and Lampriformes. The correct spelling of the order is Lampridiformes following the nomenclatorial review of Colin Patterson (Appendix 1 in Olney et al. 1993).
