ABSTRACT
Adults and larvae of Radiicephalus elongatus are known from only a few specimens captured in the North and South Atlantic Ocean, the eastern North Pacific Ocean and the Indo-west Pacific region (Osario 1917, Harrisson & Palmer 1968, Heemstra & Kannemeyer 1984, Olney 1984, Olney et al. 1993, Charter & Moser 1996c). The species is the monotypic member of the lampridiform family Radiicephalidae and apparently occupies meso-and bathypelagic habitats in all oceans except polar seas. Adults may attain 80 cm and probably feed on small mesopelagic fishes, including myctophids (Harrisson & Palmer 1968). Eggs have not been described but are probably pelagic with chorions tinted red or brown (see Lampridiformes). Charter & Moser (1996c) illustrated a small larva (7.2 NL) and larger larvae (18-20 mm TL) were illustrated and described by Olney (1984) and Charter & Moser (1996c). Little is known of the life history, population and recruitment dynamics, patterns of age and growth, spawning behavior, details of reproductive traits and general ecology of this rare species.
