Members of the deep-sea and oceanic fish family Oreosomatidae, to which the Ox-eyed Oreo (Oreosoma atlanticum) belongs, are deep bodied and laterally compressed, with large heads and eyes and a protrusible mouth. Oreos are often found at depths below 500 meters over the continental slope in most temperate (and some tropical and subtropical) waters, perhaps especially in the southern hemisphere. Many oreo species are of significant commercial value (although O. atlanticum is not due to its small size), especially in the southern hemisphere around Australia and New Zealand where deep-sea trawling is common. (Eschmeyer et al. 1983; Lowry et al. 1994). Adult Ox-eyed Oreos have a very large eye (eye diameter is ~50-60% of head length) and a prominent horizontal ridge on the operculum (gill cover) (Lowry et al. 1996).
The Ox-eyed Oreo is found in the southeastern Atlantic and western Indian Oceans, occurring around South Africa between 30° and 35° S, and in the southwestern Pacific off Australia (including western and southern Australia) and New Zealand. Depth range range is 220 to 1550 m. (Karrer 1986, cited in Froese and Pauly 2012; Paulin et al. 1989, cited in Froese and Pauly 2012).
Ox-eyed Oreos have 6-8 dorsal spines (total), 29-31 dorsal soft rays (total), 2-3 anal spines, and 28-31 anal soft rays. Pre-juveniles are blackish violet with greenish silvery cones and irregular blotches on the back (prominent cone-like outgrowths are a distinctive feature of juvenile Oreosoma, although some other juvenile oreosomatids have similar but less dramatic protuberances on their bodies). Maximum total adult length is around 21 cm. (Karrer 1986, cited in Froese and Pauly 2012)